Potentiation of Carboplatin-Mediated DNA Damage by the Mdm2 Modulator Nutlin-3a in a Humanized Orthotopic Breast-to-Lung Metastatic Model

The quote only partly states this claim.

MCF-7 (wt-p53) cells were more sensitive to single agent Nutlin-3a than mutant p53 cells.

“As expected, MCF-7 (wt-p53) cells were more sensitive to single agent Nutlin-3a (Fig. 1D), and isobologram analysis indicated Nutlin-3a was synergistic with carboplatin (Fig. 1H).”

It may state two separate claims as one.

Combination indices were <1 for all Nutlin-3a:carboplatin ratios tested, indicating synergism between Nutlin-3a and carboplatin.

“In addition, combination indices were <1 for all Nutlin-3a:carboplatin ratios tested, again indicating synergism between Nutlin-3a and carboplatin (Supplemental Fig. S1).”

It may state two separate claims as one.

Following combination treatment, clonogenic growth was inhibited ~50% by 1.5 μM of each compound, consistent with synergism.

“In contrast, following combination treatment, clonogenic growth was inhibited ~50% by 1.5 µM of each compound, consistent with synergism (Fig. 2C).”

It may state two separate claims as one.

p73α was constitutively expressed in TMD231 cells and no large changes in p73α levels were evident following treatment.

“p73α was constitutively expressed in TMD231 cells and no large changes in p73α levels were evident following treatment.”

It may state two separate claims as one.

Body weights were only transiently affected and recovered to normal levels post-treatment.

“In regards to normal tissue toxicity, body weights were only transiently affected, and recovered to normal levels post-treatment.”

It may state two separate claims as one.

In PD study 2, γH2AX increased in single-agent- and combination-treated tumors relative to vehicle, but the increase did not reach statistical significance (p>0.05).

“Analysis of Western blots via densitometry indicated that while γH2AX increased in the single agent- and combination-treated tumors compared to vehicle-treated mice, statistical significance was not reached (p>0.05); mutant p53 levels remained unchanged across the treatment groups (Supplemental Fig. S7B).”

It may state two separate claims as one.

In a third study, complete blood counts and hematopoietic progenitors were significantly decreased in carboplatin-alone and combination groups compared with vehicle or Nutlin-3a alone, but there was no difference between carboplatin-alone and combination groups.

“While complete blood counts and hematopoietic progenitors were significantly decreased in samples from mice treated with carboplatin alone or the combination compared to vehicle or Nutlin-3a alone, there were no differences between carboplatin alone and combination groups (Fig. 6F–I).”

• Also stated in: § Discussion · plain

  “While there was a decrease in hematopoietic progenitor cells in the bone marrow of carboplatin- and Nutlin-3a/carboplatin-treated mice, the inclusion of Nutlin-3a did not lead to further increases in carboplatin-mediated toxicity.”

• AssumptionRests on an assumption: Bone marrow toxicity is a principal side effect of chemotherapeutic drugs.

It may state two separate claims as one.

In vitro exposure of TNBC cells to combination Nutlin-3a/carboplatin caused synergistic inhibition of proliferation that depended at least partly on p73α-mediated signaling.

“However, a sufficient pool of “free” p73 must exist for exposure of TNBC cells in vitro to combination Nutlin-3a/carboplatin treatment led to a synergistic inhibition of cell proliferation, which was dependent, at least in part, on p73α-mediated signaling (Figure 3B).”

• AssumptionRests on an assumption: A sufficient pool of free p73 must be present for the combination to inhibit proliferation through p73α signaling.

It may state two separate claims as one.

TMD231-CR transduced cells expressed high E2-Crimson levels, and fluorescence intensity was linearly related to the number of cells implanted in the mammary fat pad.

“TMD231-CR transduced cells expressed high levels of E2-Crimson (Supplemental Fig. S5A–B), and fluorescence intensity was linearly related to the number of cells implanted in the mammary fat pad (Supplemental Fig. S5C–D).”

It may state two separate claims as one.

Cleaved PARP was measurable in 100% of tumors after combination treatment, whereas only 50-66% of tumors had measurable cleaved PARP after vehicle, Nutlin-3a, or carboplatin treatment.

“Similar results were obtained in tumor samples probed for cleaved PARP with 100% of tumors having measureable levels of cleaved PARP following combination treatment while only 50–66% of tumors contained measureable levels of cleaved PARP following vehicle, Nutlin-3a, or carboplatin treatment (Supplemental Fig. S7D).”

It may state two separate claims as one.

Mutant p53 was highly stable in TMD231 cells, and its stability did not differ between vehicle- and combination-treated cells.

“Cycloheximide experiments indicated that mtp53 was highly stable and no differences in mtp53 stability were observed in vehicle- versus combination treated TMD231 cells (Supplemental Fig. S4).”

The quote only partly states this claim.

In the second orthotopic study, the Nutlin-3a/carboplatin combination significantly increased survival probability compared with single-agent therapy, using primary tumor volume ≥800 mm3 as the survival endpoint.

“In contrast to single-agent therapy, the Nutlin-3a/carboplatin combination significantly increased the probability of survival (Fig. 6D).”

It may state two separate claims as one.

Activated Caspase-3 was detectable in 50% of vehicle-treated tumors and in 100% of tumors treated with Nutlin-3a, carboplatin, or the combination.

“While activated Caspase-3 was detectable in 50% of the vehicle-treated tumors, activated Caspase-3 was detected in 100% of the tumors treated with Nutlin-3a, carboplatin, or combination (Supplemental Fig. S7C).”

It may state two separate claims as one.

Tumor fluorescence in the mammary fat pad was detected as early as 7 days after implantation in nearly all mice, before lung metastatic foci were detected.

“Fluorescence intensity from tumors was detected in the mammary fat pad as early as 7 days post-implantation in nearly 100% of the mice, which is a time point before detection of metastatic foci in the lungs (Fig. 4A–B) and was used to block-randomize mice into treatment groups at day 7 post-implantation (Supplemental Fig. S5F–G).”

It may state two separate claims as one.

In vivo efficacy experiments demonstrated a statistically significant reduction in primary tumor volume as well as lung metastases with significantly increased probability of survival compared to vehicle and single-agent treatments.

“In vivo efficacy experiments, conducted in the TMD231 orthotopic mammary fat pad model in NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice, demonstrated a statistically significant reduction in primary tumor volume as well as lung metastases with significantly increased probability of survival compared to vehicle and single-agent treatments.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

In the TMD231 cells, the predominant form of p73 detected was the alpha isoform.

“In the TMD231 cells, the predominant form of p73 detected was the alpha isoform (~80kDa, A300-126A, Bethyl Laboratories).”

It may state two separate claims as one.

In NSG mice, TMD231 fat pad tumors were palpable by day 7 after implantation but could not be accurately measured by calipers until about day 14 or later, when tumor burden rose rapidly at both primary and lung sites.

“In NSG mice, TMD231 fat pad tumors were palpable by day 7 post-implantation, but the tumors were too small to be accurately measured by calipers until approximately day 14 or later, a time point at which tumor burden rapidly increases at both the primary and lung metastatic sites.”

It may state two separate claims as one.

At 5 days after treatment, total bone marrow cell counts were significantly reduced in combination-treated mice relative to other groups, but by 14-28 days after treatment bone marrow cellularity had recovered to control levels.

“At 5 days post-treatment, total bone marrow cell counts (Fig. 6E, left panel) were significantly reduced in combination-treated mice relative to the other groups. However, by 14–28 days post-treatment (Recovery), bone marrow cellularity had recovered to control levels (Fig. 6E, right panel).”

It may state two separate claims as one.

TMD231 tumors implanted in NSG mice grew more consistently and faster, and lung metastases appeared earlier, than in Nod/Scid mice.

“In contrast to Nod/Scid mice, TMD231 tumors implanted in NSG mice grew more consistently, at a faster rate, and lung metastases were detected earlier following implant (Fig. 4A–B).”

It may state two separate claims as one.

Body weights were transiently reduced by carboplatin and the combination, but by study end all body weights were within normal range.

“Body weights were transiently reduced by carboplatin and the combination of Nutlin-3a/carboplatin; however, by the end of the study, all body weights were within a normal range (Fig. 5B).”

It may state two separate claims as one.

No visual signs of dehydration, diarrhea, or gastrointestinal hemorrhaging were observed.

“In addition, there were no visual signs of dehydration, diarrhea, or hemorrhaging of the gastrointestinal tract.”

It may state two separate claims as one.

In PD study 1, Mdm2 levels were overall higher in Nutlin-3a-treated tumors than in vehicle-treated tumors, but the difference was not significant (p=0.08).

“While Mdm2 levels were overall higher in tumors from the Nutlin-3a treated group versus vehicle, it was not significant (p=0.08).”

It may state two separate claims as one.

In a second orthotopic study, combination treatment significantly reduced tumor volumes compared with vehicle and single-agent treatments, with only a transient decrease in body weights during therapy.

“Similar to the previous study (Fig. 5), the combination treatment led to significantly reduced tumor volumes when compared to vehicle and single agent treatments (Fig. 6A) with only a transient decrease in body weights during therapy (Fig. 6B).”

It may state two separate claims as one.

Median survival in the second study was 40±1.5 days for vehicle, 40±8.1 days for Nutlin-3a, 47±2.6 days for carboplatin, and 54.3±0.9 days for the combination.

“Median survival was 40±1.5 days for vehicle, 40±8.1 for Nutlin-3a, 47±2.6 for carboplatin, and 54.3±0.9 days for the combination (Fig. 6D).”

It may state two separate claims as one.

Median survival in the carboplatin dose-finding study was 41±3.6 days for vehicle, 44±4.3 days for 1 mg/kg, 48±1.9 days for 3 mg/kg, and 58±0 days for 30 mg/kg carboplatin.

“The median survival was 41±3.6 days for vehicle, 44±4.3 days for 1 mg/kg, 48±1.9 days for 3 mg/kg, and 58±0 days for 30 mg/kg of carboplatin (Fig. 4D).”

It may state two separate claims as one.

In MCF10A epithelial and human fibroblast cells, combination treatment reduced in vitro cell growth compared with carboplatin alone but did not reduce growth beyond Nutlin-3a alone.

“In MCF10A epithelial and human fibroblast cells, the combination treatment decreased cell growth in vitro compared to carboplatin alone but did not decrease cell growth beyond that of Nutlin-3a alone.”

Probably not a substantial claim.

Mdm2 is an E3 ubiquitin ligase that targets p53 for proteasomal degradation.

“Mdm2 is a E3 ubiquitin ligase that targets p53 for degradation by the proteasome (7)”

• cites [7] Haupt, 1997, Mdm2 promotes the rapid degradation of p53, Nature sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Clinical studies indicate that platinum-based therapy can provide enhanced efficacy in triple-negative breast cancer.

“Clinical studies have indicated that platinum-based therapy can provide enhanced efficacy in TNBC (4, 5).”

• cites [4] Villarreal-Garza, 2014, Platinum-based chemotherapy in triple-negative advanced breast cancer, Breast Cancer Res Treat sourceNot checked yet
• cites [5] Hurley, 2013, The use of neoadjuvant platinum-based chemotherapy in locally advanced breast cancer that is triple negative: retrospective analysis of 144 patients, Breast Cancer Res Treat sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Mdm2 is a multi-faceted protein involved in cell growth, survival, and invasion.

“Mdm2 is a multi-faceted protein involved in numerous aspects of cell growth, survival, and invasion (6).”

• cites [6] Rayburn, 2005, MDM2 and human malignancies: expression, clinical pathology, prognostic markers, and implications for chemotherapy, Curr Cancer Drug Targets sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Development of effective therapies for triple-negative breast cancer is challenging because the disease is aggressive and lacks targetable hormone receptors.

“The development of efficacious therapies for TNBC has been challenging due to its aggressive nature and lack of hormone receptors that can be therapeutically targeted (1, 2).”

• cites [1] Schnitt, 2010, Classification and prognosis of invasive breast cancer: from morphology to molecular taxonomy, Mod Pathol sourceNot checked yet
• cites [2] Dent, 2007, Triple-negative breast cancer: clinical features and patterns of recurrence, Clin Cancer Res sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Clinical trials are evaluating combination therapies that include carboplatin for metastatic triple-negative breast cancer.

“Furthermore, clinical trials are currently evaluating the utility of combination therapies that include carboplatin to specifically treat TNBCs with metastases (NCT01881230, NCT00691379, and NCT01281150; www.clinicaltrials.gov).”

• cites NCT01881230, NCT00691379, and NCT01281150Not checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Platinum agents such as cisplatin and carboplatin form DNA-platinum adducts that create intra- and interstrand crosslinks, leading to double-strand breaks and cell death.

“Platinum agents, such as cisplatin and carboplatin, form DNA-platinum adducts resulting in intra- and interstrand DNA crosslinks leading to increased double strand breaks and cell death (3).”

• cites [3] Fuertes, 2003, Cisplatin biochemical mechanism of action: from cytotoxicity to induction of cell death through interconnections between apoptotic and necrotic pathways, Curr Med Chem sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Mdm2 gene amplifications are found in 10-60% of breast cancers.

“In breast cancers, studies have shown Mdm2 gene amplifications range from 10–60% with some studies indicating a worse prognosis with overexpression of Mdm2 or gene amplification (6, 8).”

• cites [6] Rayburn, 2005, MDM2 and human malignancies: expression, clinical pathology, prognostic markers, and implications for chemotherapy, Curr Cancer Drug Targets sourceNot checked yet
• cites [8] Araki, 2010, TGF-beta1-induced expression of human Mdm2 correlates with late-stage metastatic breast cancer, J Clin Invest sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Platinum agents lead to S and G2/M accumulation.

“Cell cycle analysis indicated that the TMD231 cell line had both diploid and aneuploid subpopulations and that carboplatin-treated TMD231 cells accumulated in S and G2/M in both subpopulations (Supplemental Fig. S3), which is consistent with previous reports that platinum agents lead to S and G2/M accumulation (31).”

• cites [31] Smith, 1999, Mdm2 sensitizes MCF7 breast cancer cells to cisplatin or carboplatin, Breast Cancer Res Treat sourceNot checked yet

Probably not a substantial claim.

p73 is rarely mutated in cancers.

“in contrast, p73 is rarely mutated in cancers (14, 16).”

• cites [14] Soussi, 2001, Assessing TP53 status in human tumours to evaluate clinical outcome, Nat Rev Cancer sourceNot checked yet
• cites [16] Dotsch, 2010, p63 and p73, the ancestors of p53, Cold Spring Harb Perspect Biol sourceNot checked yet

Probably not a substantial claim. It may state two separate claims as one.

p73 is a member of the p53 family of tumor suppressors and has similar transactivation functions relating to induction of pro-apoptotic genes in response to cellular stress.

“p73 is a member of the p53 family of tumor suppressors and has similar transactivation functions relating to the induction of pro-apoptotic genes in response to cellular stress (17, 18).”

• cites [17] Jost, 1997, p73 is a simian [correction of human] p53-related protein that can induce apoptosis, Nature sourceNot checked yet
• cites [18] Melino, 2004, p73 Induces apoptosis via PUMA transactivation and Bax mitochondrial translocation, J Biol Chem sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

p53 is mutated in approximately 50% of all cancers.

“It is estimated that p53 is mutated in approximately 50% of all cancers with 60% of TNBCs bearing mutations in p53 (14, 15);”

• cites [14] Soussi, 2001, Assessing TP53 status in human tumours to evaluate clinical outcome, Nat Rev Cancer sourceNot checked yet
• cites [15] Shah, 2012, The clonal and mutational evolution spectrum of primary triple-negative breast cancers, Nature sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

60% of triple-negative breast cancers bear mutations in p53.

“It is estimated that p53 is mutated in approximately 50% of all cancers with 60% of TNBCs bearing mutations in p53 (14, 15);”

• cites [14] Soussi, 2001, Assessing TP53 status in human tumours to evaluate clinical outcome, Nat Rev Cancer sourceNot checked yet
• cites [15] Shah, 2012, The clonal and mutational evolution spectrum of primary triple-negative breast cancers, Nature sourceNot checked yet

It may state two separate claims as one.

Nutlin-3a binds the N-terminal hydrophobic pocket of Mdm2 and blocks protein-protein interactions between Mdm2 and p53.

“Nutlin-3a is a small molecule, which binds to the N-terminal hydrophobic pocket of Mdm2 and blocks protein-protein interactions (PPIs) between Mdm2 and p53 (10).”

• cites [10] Vassilev, 2004, In vivo activation of the p53 pathway by small-molecule antagonists of MDM2, Science sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

High Mdm2 levels correlate with a higher incidence of metastasis in vivo.

“Moreover, evidence suggests that high Mdm2 levels correlate with a higher incidence of metastasis in vivo (6, 8, 9).”

• cites [6] Rayburn, 2005, MDM2 and human malignancies: expression, clinical pathology, prognostic markers, and implications for chemotherapy, Curr Cancer Drug Targets sourceNot checked yet
• cites [8] Araki, 2010, TGF-beta1-induced expression of human Mdm2 correlates with late-stage metastatic breast cancer, J Clin Invest sourceNot checked yet
• cites [9] Chen, 2013, MDM2 promotes invasion and metastasis in invasive ductal breast carcinoma by inducing matrix metalloproteinase-9, PLoS One sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Some studies indicate that Mdm2 overexpression or gene amplification is associated with worse prognosis in breast cancer.

“In breast cancers, studies have shown Mdm2 gene amplifications range from 10–60% with some studies indicating a worse prognosis with overexpression of Mdm2 or gene amplification (6, 8).”

• cites [6] Rayburn, 2005, MDM2 and human malignancies: expression, clinical pathology, prognostic markers, and implications for chemotherapy, Curr Cancer Drug Targets sourceNot checked yet
• cites [8] Araki, 2010, TGF-beta1-induced expression of human Mdm2 correlates with late-stage metastatic breast cancer, J Clin Invest sourceNot checked yet

It may state two separate claims as one.

Lau and colleagues showed that Nutlin-3a treatment inhibits p73α binding to Mdm2, leading to p73α-mediated induction of pro-apoptotic downstream targets and increased apoptosis in cells lacking wild-type p53.

“Lau and colleagues showed that when cells were treated with Nutlin-3a, the binding of p73α to Mdm2 was inhibited, leading to p73α-mediated induction of pro-apoptotic downstream targets and increased apoptosis in cells lacking wild-type p53 (12).”

• cites [12] Lau, 2008, HDM2 antagonist Nutlin-3 disrupts p73-HDM2 binding and enhances p73 function, Oncogene sourceNot checked yet

Probably not a substantial claim.

p53 and p73α both interact with Mdm2 in the same N-terminal hydrophobic pocket.

“While p53 and p73α can both interact with Mdm2 in the same N-terminal hydrophobic pocket (12), Mdm2 does not ubiquitinate p73α (44–46).”

• cites [12] Lau, 2008, HDM2 antagonist Nutlin-3 disrupts p73-HDM2 binding and enhances p73 function, Oncogene sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Mice were block-randomized to treatment groups based on tumor fluorescence intensity.

“Mice were optically imaged on day 7 and block-randomized to treatment groups based on tumor fluorescence intensity: vehicle (Veh; PBS+methylcellulose/Tween80), 25 mg/kg carboplatin i.p. (Carb) (in AM), 200 mg/kg Nutlin-3a p.o. (Nut) (in PM), or 25 mg/kg carboplatin+200 mg/kg Nutlin-3a (Combo), and were dosed three times weekly for 2 weeks.”

Probably not a substantial claim. It may state two separate claims as one.

p73α has functions similar to p53 but is regulated differently by Mdm2.

“The p53 family member p73α has functions similar to p53 (17, 18, 42, 43), but is regulated differently by Mdm2.”

• cites [17] Jost, 1997, p73 is a simian [correction of human] p53-related protein that can induce apoptosis, Nature sourceNot checked yet
• cites [18] Melino, 2004, p73 Induces apoptosis via PUMA transactivation and Bax mitochondrial translocation, J Biol Chem sourceNot checked yet
• cites [42] Zawacka-Pankau, 2010, p73 tumor suppressor protein: a close relative of p53 not only in structure but also in anti-cancer approach?, Cell Cycle sourceNot checked yet
• cites [43] Zhu, 1998, The potential tumor suppressor p73 differentially regulates cellular p53 target genes, Cancer ResNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

TMD231 cells are a derivative of the MDA-MB-231 cell line.

“TMD231 cells were obtained from Dr. Harikrishna Nakshatri in 2009 and are a derivative of the MDA-MB-231 cell line (19).”

• cites [19] Helbig, 2003, NF-kappaB promotes breast cancer cell migration and metastasis by inducing the expression of the chemokine receptor CXCR4, J Biol Chem sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Ongoing clinical trials for metastatic TNBC include platinum agents in their treatment regimens.

“Furthermore, ongoing clinical trials for metastatic TNBC are including platinum agents in their treatment regimens (4, 36–38).”

• cites [4] Villarreal-Garza, 2014, Platinum-based chemotherapy in triple-negative advanced breast cancer, Breast Cancer Res Treat sourceNot checked yet
• cites [36] O'Shaughnessy, 2011, Iniparib plus chemotherapy in metastatic triple-negative breast cancer, N Engl J Med sourceNot checked yet
• cites [37] O'Shaughnessy, 2014, Phase III study of iniparib plus gemcitabine and carboplatin versus gemcitabine and carboplatin in patients with metastatic triple-negative breast cancer, J Clin Oncol sourceNot checked yet
• cites [38] Carey, 2012, TBCRC 001: randomized phase II study of cetuximab in combination with carboplatin in stage IV triple-negative breast cancer, J Clin Oncol sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

About 60% of basal TNBCs carry p53 mutations, and roughly 90% of p53 mutations fall in the DNA binding domain.

“Approximately 60% of basal TNBCs bear mutations in p53 (15) and ~90% of mutations in p53 occur in the DNA binding domain.”

• cites [15] Shah, 2012, The clonal and mutational evolution spectrum of primary triple-negative breast cancers, Nature sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

All studies were carried out in accordance with IACUC approval and the Guide for the Care and Use of Laboratory Animals.

“All studies were carried out in accordance with, and approval of, the Institutional Animal Care and Use Committee of Indiana University School of Medicine and the Guide for the Care and Use of Laboratory Animals.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Xu and colleagues showed that mutant p53 R282W and R110P are misfolded/aggregated, which increases aggregation with p73 and inhibits p73 function.

“Xu and colleagues demonstrated that mutant p53 (mtp53) (R282W and R110P) exhibit a misfolded/aggregated state which leads to increased aggregation of mtp53 with p73 causing inhibition of p73 function (35).”

• cites [35] Xu, 2011, Gain of function of mutant p53 by coaggregation with multiple tumor suppressors, Nat Chem Biol sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Authentication of molecular profiles was verified by STR analysis, and cells tested negative for mycoplasma.

“Authentication of molecular profiles was verified by short tandem repeat (STR) analysis (IDEXX BioResearch), and cells tested negative for mycoplasma.”

It may state two separate claims as one.

The rise in chromatin-bound Mdm2 after combination treatment is consistent with inhibition of the MRN complex and may reduce detection of carboplatin-induced DNA damage, increasing cell death.

“These findings are consistent with the interpretation that the increased localization of Mdm2 to chromatin leads to inhibition of the MRN complex (24), and may decrease the ability of cells to sense carboplatin-mediated DNA damage leading to increased cell death.”

• cites [24] Alt, 2005, Mdm2 binds to Nbs1 at sites of DNA damage and regulates double strand break repair, J Biol Chem sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

In some cell types, mutant p53 can sequester p73 and block p73-mediated downstream signaling.

“In some cell types mtp53 can sequester p73, which leads to a blockade of p73-mediated downstream signaling (35).”

• cites [35] Xu, 2011, Gain of function of mutant p53 by coaggregation with multiple tumor suppressors, Nat Chem Biol sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The p73 polyclonal antibody A300-126A recognizes multiple isoforms of p73 but does not recognize ΔNp73.

“While the p73 polyclonal antibody A300-126A recognizes multiple isoforms of p73, it does not recognize ΔNp73.”

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

The mtp53 R280K mutation in MDA-MB-231 and TMD231 cells has been reported to have gain-of-function properties, though its exact role remains unclear.

“The mtp53 R280K mutation in the MDA-MB-231 and the TMD231 cells has been reported to have gain-of function properties (34); however, its exact role is still not well understood.”

• cites [34] Hui, 2006, Mutant p53 in MDA-MB-231 breast cancer cells is stabilized by elevated phospholipase D activity and contributes to survival signals generated by phospholipase D, Oncogene sourceNot checked yet

It may state two separate claims as one.

Although the study did not show direct interaction between chromatin-associated Mdm2 and the MRN complex, the increase in chromatin-bound Mdm2 after Nutlin-3a or combination treatment is consistent with Eischen and colleagues' findings.

“While our studies do not demonstrate a direct interaction of chromatin-associated Mdm2 with the MRN complex, increases in Mdm2 associated chromatin following Nutlin-3a or combination Nutlin-3a/carboplatin are consistent with studies of Eischen and colleagues.”

• cites [48] Carrillo, 2015, Pharmacologically increasing Mdm2 Inhibits DNA repair and cooperates with genotoxic agents to kill p53-inactivated ovarian cancer cells, Mol Cancer Res sourceNot checked yet

It may state two separate claims as one.

Combination Nutlin-3a/carboplatin treatment shows promise for efficacy with minimal normal tissue toxicity compared with carboplatin alone.

“Thus, combination Nutlin-3a/carboplatin treatment shows promise of efficacy with minimal effects on normal tissue toxicity compared to carboplatin-alone.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Jiang et al. reported that Nutlin-3 can protect renal cells from cisplatin-based therapy.

“Jiang et al. previously reported that Nutlin-3 could protect renal cells from cisplatin-based therapy (49).”

• cites [49] Jiang, 2007, Nutlin-3 protects kidney cells during cisplatin therapy by suppressing Bax/Bak activation, J Biol Chem sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it. It may state two separate claims as one.

Eischen and colleagues showed that Nutlin-3a-induced Mdm2 directly inhibits DNA damage response signaling and delays DNA break repair in p53-null MEFs and in ovarian cancer cell lines lacking p53 or carrying mutant p53.

“They demonstrated that Nutlin-3a–induced increased levels of Mdm2 directly inhibit DNA damage response signaling and delayed DNA break repair in p53-null MEFs and in ovarian cancer cell lines that lacked p53 or that contained mutant p53 (48).”

• cites [48] Carrillo, 2015, Pharmacologically increasing Mdm2 Inhibits DNA repair and cooperates with genotoxic agents to kill p53-inactivated ovarian cancer cells, Mol Cancer Res sourceNot checked yet

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Mdm2 binds directly to Nbs1 of the Mre11/Rad50/Nbs1 complex.

“It has been previously demonstrated that Mdm2 binds directly to Nbs1 of the Mre11/Rad50/Nbs1 (MRN) complex, co-localizes with Nbs1 to DNA damage foci, and inhibits the DNA damage response (24, 25).”

• cites [24] Alt, 2005, Mdm2 binds to Nbs1 at sites of DNA damage and regulates double strand break repair, J Biol Chem sourceNot checked yet
• cites [25] Bouska, 2008, Mdm2 promotes genetic instability and transformation independent of p53, Mol Cell Biol sourceNot checked yet

It may state two separate claims as one.

Nutlin-3a blockade of Mdm2 binding to p73α increases the available p73α pool, allowing transcriptional activation of pro-apoptotic genes and apoptosis in mutant p53 and p53-null cells.

“Blockade of the binding of Mdm2 to p73α by Nutlin-3a increases the pool of p73α available to transcriptionally activate pro-apoptotic gene expression and promote apoptosis in mutant p53 and p53 null cells (12).”

• cites [12] Lau, 2008, HDM2 antagonist Nutlin-3 disrupts p73-HDM2 binding and enhances p73 function, Oncogene sourceNot checked yet

It may state two separate claims as one.

The optimized breast-to-lung orthotopic model can be used to test novel platinum-based combination regimens and to study how to potentiate DNA damage in TNBC at primary and metastatic sites.

“The optimized breast-to-lung orthotopic model described here can be used to test novel combination platinum-based regimens and further increase our understanding of how to therapeutically potentiate DNA damage in TNBC at primary and metastatic sites.”

It may state two separate claims as one.

The present studies support Mdm2 as a promising therapeutic target in combination with current TNBC therapies and may lead to new clinical therapies for TNBC and metastases.

“The present studies demonstrate the promise of Mdm2 as a therapeutic target in combination with current therapeutic approaches for TNBC, and may lead to new clinical therapies for TNBC and metastases.”

Probably not a substantial claim. The paper’s conclusions may not depend on it.

Mdm2 co-localizes with Nbs1 at DNA damage foci.

“It has been previously demonstrated that Mdm2 binds directly to Nbs1 of the Mre11/Rad50/Nbs1 (MRN) complex, co-localizes with Nbs1 to DNA damage foci, and inhibits the DNA damage response (24, 25).”

• cites [24] Alt, 2005, Mdm2 binds to Nbs1 at sites of DNA damage and regulates double strand break repair, J Biol Chem sourceNot checked yet
• cites [25] Bouska, 2008, Mdm2 promotes genetic instability and transformation independent of p53, Mol Cell Biol sourceNot checked yet