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Biology subjects

Kundra, R.

Publications and source records attributed to Kundra, R..

4 recordsLinked to original sources

Integrative analysis of the MD Anderson Prostate Cancer Patient-Derived Xenograft Series (MDA PCa PDX)

Progress in understanding prostate cancer (PCa) metastasis and therapy resistance has been hampered by the lack of models, representative of the clinical spectrum and biologic complexity of the disease. Our laboratory is home to one of the largest worldwide repositories of PCa patient-derived xenografts (PDXs), the MDA PCa PDX series, a collection of clinically annotated PDXs reflecting the full spectrum of potentially lethal disease, that includes tumors that are not end stage and not castration-resistant PCa. We performed whole genome sequencing, targeted sequencing and RNA sequencing of 46 MDA PCa PDX models derived from biopsy and surgical specimens from 39 patients, selected in order to reflect the clinicopathological PCa subtypes (data available in cBioPortal). MDA PCa PDXs genomic characterization shows that the cohort recapitulates the mutational landscape found in PCa, highlighting the clinical relevance of these models. Interestingly and consistently with the clinic, certain models lack the typical PCa driver alterations, thus providing a suitable tool for discovery of novel drivers. Our cohort also includes PDXs derived from different areas of the same tumor and longitudinal samples, allowing to study disease heterogeneity and progression. Finally, we have developed a procedure to grow organoids from PDXs, thus providing a powerful in vitro platform that supports hypothesis generation, and testing of clinically relevant observations. Genomic and transcriptomic characterization of MDA PCa PDXs together with the ability to grow them as organoids for in vitro experimentation, provides a unique resource to address the existing clinical gap in PCa, helping to better understand mechanisms of response and resistance. One Sentence SummaryMDA PCa PDX series is a dynamic resource capturing the molecular landscape of prostate cancer; a platform for discovery and personalized medicine

cancer biology↗

Immune and malignant cell phenotypes of ovarian cancer are determined by distinct mutational processes

High-grade serous ovarian cancer (HGSOC) is an archetypal cancer of genomic instability patterned by distinct mutational processes, intratumoral heterogeneity and intraperitoneal spread. We investigated determinants of immune recognition and evasion in HGSOC to elucidate co- evolutionary processes underlying malignant progression and tumor immunity. Mutational processes and anatomic sites of tumor foci were key determinants of tumor microenvironment cellular phenotypes, inferred from whole genome sequencing, single-cell RNA sequencing, digital histopathology and multiplexed immunofluorescence of 160 tumor sites from 42 treatment-naive HGSOC patients. Homologous recombination-deficient (HRD)-Dup (BRCA1 mutant-like) and HRD- Del (BRCA2 mutant-like) tumors harbored increased neoantigen burden, inflammatory signaling and ongoing immunoediting, reflected in loss of HLA diversity and tumor infiltration with highly- differentiated dysfunctional CD8+ T cells. Foldback inversion (FBI, non-HRD) tumors exhibited elevated TGF{beta} signaling and immune exclusion, with predominantly naive/stem-like and memory T cells. Our findings implicate distinct immune resistance mechanisms across HGSOC subtypes which can inform future immunotherapeutic strategies. HIGHLIGHTSO_LIMulti-region, multi-modal profiling of malignant and immune cell phenotypes in ovarian cancer C_LIO_LIAnatomic site specificity is a determinant of cancer cell and intratumoral immune phenotypes C_LIO_LITumor mutational processes impact mechanisms of immune control and immune evasion C_LIO_LISpatial topology of HR-deficient tumors is defined by immune interactions absent from immune inert HR-proficient subtypes C_LI

cancer biology↗

Genomic characterization of metastatic patterns from prospective clinical sequencing of 25,000 patients

Progression to metastatic disease remains the main cause of cancer death. Yet, the underlying genomic mechanisms driving metastasis remain largely unknown. Here, we present MSK-MET, an integrated pan-cancer cohort of tumor genomic and clinical outcome data from more than 25,000 patients. We analyzed this dataset to identify associations between tumor genomic alterations and patterns of metastatic dissemination across 50 tumor types. We found that chromosomal instability is strongly correlated with metastatic burden in some tumor types, including prostate adenocarcinoma, lung adenocarcinoma and HR-positive breast ductal carcinoma, but not in others, such as colorectal adenocarcinoma, pancreatic adenocarcinoma and high-grade serous ovarian cancer. We also identified specific somatic alterations associated with increased metastatic burden and specific routes of metastatic spread. Our data offer a unique resource for the investigation of the biological basis for metastatic spread and highlight the crucial role of chromosomal instability in cancer progression.

cancer biology↗

Cytosolic aggregation of mitochondrial proteins disrupts cellular homeostasis by stimulating other proteins aggregation

Mitochondria are organelles with their own genomes, but they rely on the import of nuclear-encoded proteins that are translated by cytosolic ribosomes. Therefore, it is important to understand whether failures in the mitochondrial uptake of these nuclear-encoded proteins can cause proteotoxic stress and identify response mechanisms that may counteract it. Here, we report that upon impairments in mitochondrial protein import, high-risk precursor and immature forms of mitochondrial proteins form aberrant deposits in the cytosol. These deposits then cause further cytosolic accumulation and consequently aggregation of other mitochondrial proteins and disease-related proteins, including -synuclein and amyloid {beta}. This aggregation triggers a cytosolic protein homeostasis imbalance that is accompanied by specific molecular chaperone responses at both the transcriptomic and protein levels. Altogether, our results provide evidence that mitochondrial dysfunction, specifically protein import defects, contributes to impairments in protein homeostasis, thus revealing a possible molecular mechanism by which mitochondria are involved in neurodegenerative diseases.

molecular biology↗