Cited by 147Gene expression and cancer classificationTopological and Geometric Data AnalysisAdvanced Clustering Algorithms Research

Sorting points into neighborhoods (SPIN): data analysis and visualization by ordering distance matrices

Open access
Tsafrir, D., Tsafrir, I., Ein-Dor, L., Zuk, O., Notterman, D.A., Domany, E.·2005·Bioinformatics

Abstract

SUMMARY: We introduce a novel unsupervised approach for the organization and visualization of multidimensional data. At the heart of the method is a presentation of the full pairwise distance matrix of the data points, viewed in pseudocolor. The ordering of points is iteratively permuted in search of a linear ordering, which can be used to study embedded shapes. Several examples indicate how the shapes of certain structures in the data (elongated, circular and compact) manifest themselves visually in our permuted distance matrix. It is important to identify the elongated objects since they are often associated with a set of hidden variables, underlying continuous variation in the data. The problem of determining an optimal linear ordering is shown to be NP-Complete, and therefore an iterative search algorithm with O(n3) step-complexity is suggested. By using sorting points into neighborhoods, i.e. SPIN to analyze colon cancer expression data we were able to address the serious problem of sample heterogeneity, which hinders identification of metastasis related genes in our data. Our methodology brings to light the continuous variation of heterogeneity--starting with homogeneous tumor samples and gradually increasing the amount of another tissue. Ordering the samples according to their degree of contamination by unrelated tissue allows the separation of genes associated with irrelevant contamination from those related to cancer progression. AVAILABILITY: Software package will be available for academic users upon request.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1093/bioinformatics/bti329

Cites

23 of 23 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Pseudoalignment reduces quantification time by two orders of magnitude without compromising accuracy.

    “by replacing read alignment with pseudoalignment, i.e., by only identifying the transcripts from which a read could have originated without determining the exact sequence alignments between them, the time required to perform quantification (assigning expression values to genes) is decreased by two orders of magnitude without compromising accuracy.”
  • scRNA-seq reads can be used to cluster cells using features other than explicitly quantified gene expression.

    “Interestingly, scRNA-seq reads can be used to cluster cells based on features other than explicitly quantified gene expression.”
  • The BackSPIN algorithm has been extensively validated using computational and biological validation tools.

    “The algorithm has by now been extensively validated using both computational (including comparisons to PCA, and independent-component analysis, tSNE, and GP-LVM) biological validation tools 9, 63–66.”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Tsafrir,D. et al. (2004) A novel mathematical approach to analyzing gene expression data: results from an international colon cancer consortium. In Proceedings of AACR 2004.

Cited by

Sorted by citations

Authors
Tsafrir, D., Tsafrir, I., Ein-Dor, L., Zuk, O., Notterman, D. A., & Domany, E.
Affiliations
Weizmann Institute of Science (IL)
Corresponding author
Tsafrir, D.
ORCID
Zuk, O.
Venue
Bioinformatics
Published
2005-02-18
Volume
21
Issue
10
Pages
2301-2308
ISSN
  • 0266-7061 (ISSN-L)
  • 1367-4803
  • 1460-2059
OpenAlex
W2136941630
Cited by
146
References
23
Citations by year
2026: 5 · 2025: 7 · 2024: 2 · 2023: 11 · 2022: 4 · 2021: 8 · 2020: 10 · 2019: 12 · 2018: 6 · 2017: 4 · 2016: 14 · 2015: 14 · 2014: 2 · 2013: 2 · 2012: 4
FWCI
3.15
Type
journal article
Language
en
Open access
Locations
  • Computer applications in the biosciences (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Rutgers Cancer Institute of New Jersey
  • National Institutes of Health
  • National Cancer Institute (5 P01 CA 65930-06, P01CA065930)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Gene expression and cancer classification
  • Physical Sciences › Computer Science › Computational Theory and Mathematics › Topological and Geometric Data Analysis
  • Physical Sciences › Computer Science › Artificial Intelligence › Advanced Clustering Algorithms Research
Keywords
high-dimensional data visualization, linear ordering, NP-completeness, sample heterogeneity, metastasis-associated genes, tissue contamination
MeSH terms
Algorithms, Colonic Neoplasms, Computer Graphics, Computer Simulation, Data Interpretation, Statistical, Diagnosis, Computer-Assisted, Humans, Models, Biological, Neoplasm Proteins, Pattern Recognition, Automated, Software, Biomarkers, Tumor, User-Computer Interface, Cluster Analysis, Information Storage and Retrieval, Gene Expression Profiling

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review