Biology subjects

Lazebnik, Y.

Publications and source records attributed to Lazebnik, Y..

3 recordsLinked to original sources

bioRxiv2019

Peculiar cases of a \"sleeping\" brain in alert cancer patients

Cognitive and constitutional symptomatology is common in cancer patients but the causes are not well understood. To investigate whether cancers cause these symptoms by changing cerebral metabolism, we measured the cerebral rate of glucose consumption (CMRglc) in patients diagnosed with a lung lesion.\n\nMethodsThe CMRglc was quantified in 20 patients undergoing 18F-FDG PET for lesion staging. The cognitive status was assessed by neuropsychological testing.\n\nResultsParadoxically, despite being alert three of the patients had CMRglc typical of people who are in deep sleep or anesthetized. All three had cancers, two died within 2 months of scanning. Remaining patients including four with early stage cancer had CMRglc within normal range.\n\nConclusionsWe speculate that the low CMRglc reflects a switch to an alternative energy source that is mediated by cancers remotely. Identifying the underlying mechanism and the alternative energy sources may help to understand how cancers can change body metabolism.

cancer biology↗

bioRxiv2019

Cancer-type specific aneuploidies hard-wire chromosome-wide gene expression patterns of their tissue of origin

Most carcinomas have characteristic chromosomal aneuploidies specific to the tissue of tumor origin. The reason for this specificity is unknown. As aneuploidies directly affect gene expression, we hypothesized that cancer-type specific aneuploidies, which emerge at early stages of tumor evolution, confer adaptive advantages to the physiological requirements of the tissue of origin. To test this hypothesis, we compared chromosomal aneuploidies reported in the TCGA database to chromosome arm-wide gene expression levels of normal tissues from the GTEx database. We find that cancer-type specific chromosomal aneuploidies mirror differential gene expression levels specific to the respective normal tissues which cannot be explained by copy number alterations of resident cancer driver genes. We propose that cancer-type specific aneuploidies "hard-wire" chromosome arm-wide gene expression levels present in normal tissues, favoring clonal expansion and tumorigenesis. One sentence summaryThe clonal evolution of cancer is initiated by tissue-specific transcriptional requirements

cancer biology↗

bioRxiv2017

Science with no fiction: measuring the veracity of scientific reports by citation analysis

The current crisis of veracity in biomedical research is enabled by the lack of publicly accessible information on whether the reported scientific claims are valid. One approach to solve this problem is to replicate previous studies by specialized reproducibility centers. However, this approach is costly or unaffordable and raises a number of yet to be resolved concerns that question its effectiveness and validity. We propose to use an approach that yields a simple numerical measure of veracity, the R-factor, by summarizing the outcomes of already published studies that have attempted to test a claim. The R-factor of an investigator, a journal, or an institution would be the average of the R-factors of the claims they reported. We illustrate this approach using three studies recently tested by a replication initiative, compare the results, and discuss how using the R-factor can help improve the veracity of scientific research.

scientific communication and education↗