Publications by authors named "Somnath Mahapatra"

Inadequate response to androgen deprivation therapy (ADT) frequently arises in prostate cancer, driven by cellular mechanisms that remain poorly understood. Here, we integrated single-cell RNA sequencing, single-cell multiomics, and spatial transcriptomics to define the transcriptional, epigenetic, and spatial basis of cell identity and castration response in the mouse prostate. Leveraging these data along with a meta-analysis of human prostates and prostate cancer, we identified cellular orthologs and key determinants of ADT response and resistance.

View Article and Find Full Text PDF

How cancer cells escape immune surveillance and resist immune checkpoint blockade (ICB) remains to be fully elucidated. By screening candidate genes frequently gained in cancer, we identified expression of ubiquitin-like modifier activating enzyme 1 (UBA1) as being the most negatively correlated with signatures related to effector CD8+ T-cells. High UBA1 expression was strongly predictive of treatment resistance and poor survival in ICB cohorts.

View Article and Find Full Text PDF

Selective degradation of cyclin-dependent kinases 12 and 13 (CDK12/13) emerges as a new potential therapeutic approach for triple-negative breast cancer (TNBC) and other human cancers. While several proteolysis-targeting chimera (PROTAC) degraders of CDK12/13 were reported, none are orally bioavailable. Here, we report the discovery of as a potent, selective, and orally bioavailable CDK12/13 PROTAC degrader.

View Article and Find Full Text PDF
Article Synopsis
  • Biallelic loss of CDK12 is linked to a specific subtype of metastatic castration-resistant prostate cancer (mCRPC), raising questions about its role in cancer development versus exposing drug targets.
  • Research shows that loss of CDK12 leads to early cancer-like changes and enhances cancer cell growth when combined with mutations in other genes like Trp53, while it inhibits tumor growth in the absence of another tumor suppressor gene, Pten.
  • CDK12 loss causes genomic instability and makes tumors sensitive to treatments targeting another protein, CDK13, highlighting CDK12 as a crucial tumor suppressor and suggesting new therapeutic approaches for CDK12-mutant mCRPC.
View Article and Find Full Text PDF

Cyclin-dependent kinases 12/13 play pivotal roles in orchestrating transcription elongation, DNA damage response, and maintenance of genomic stability. Biallelic CDK12 loss has been documented in various malignancies. Here, we develop a selective CDK12/13 PROTAC degrader, YJ9069, which effectively inhibits proliferation in subsets of prostate cancer cells preferentially over benign immortalized cells.

View Article and Find Full Text PDF
Article Synopsis
  • The androgen receptor (AR) is important for prostate cell differentiation, but its role changes in cancer, leading to enhanced tumor traits due to altered chromatin interactions.
  • This study reveals that the NSD2 enzyme, which is overexpressed in prostate cancer, is crucial for the function of tumor-specific AR enhancers by affecting their chromatin makeup.
  • Targeting both NSD1 and NSD2 may provide an effective treatment strategy for advanced prostate cancer, especially seen with a specialized degrader that shows strong effects in AR-driven cancer models.
View Article and Find Full Text PDF

The POU2F3-POU2AF2/3 transcription factor complex is the master regulator of the tuft cell lineage and tuft cell-like small cell lung cancer (SCLC). Here, we identify a specific dependence of the POU2F3 molecular subtype of SCLC (SCLC-P) on the activity of the mammalian switch/sucrose non-fermentable (mSWI/SNF) chromatin remodeling complex. Treatment of SCLC-P cells with a proteolysis targeting chimera (PROTAC) degrader of mSWI/SNF ATPases evicts POU2F3 and its coactivators from chromatin and attenuates downstream signaling.

View Article and Find Full Text PDF

Nephrogenic adenoma (NA) is a benign, reactive lesion seen predominantly in the urinary bladder and often associated with antecedent inflammation, instrumentation, or an operative history. Its histopathologic diversity can create diagnostic dilemmas and pathologists use morphologic evaluation along with available immunohistochemical (IHC) markers to navigate these challenges. IHC assays currently do not designate or specify NA's potential putative cell of origin.

View Article and Find Full Text PDF

There is tremendous need for improved prostate cancer models. Anatomically and developmentally, the mouse prostate differs from the human prostate and does not form tumors spontaneously. Genetically engineered mouse models lack the heterogeneity of human cancer and rarely establish metastatic growth.

View Article and Find Full Text PDF

Prostate cancer is an exemplar of an enhancer-binding transcription factor-driven disease. The androgen receptor (AR) enhanceosome complex comprised of chromatin and epigenetic coregulators assembles at enhancer elements to drive disease progression. The paralog lysine acetyltransferases p300 and CBP deposit histone marks that are associated with enhancer activation.

View Article and Find Full Text PDF

Mammalian switch/sucrose nonfermentable (mSWI/SNF) ATPase degraders have been shown to be effective in enhancer-driven cancers by functioning to impede oncogenic transcription factor chromatin accessibility. Here, we developed AU-24118, an orally bioavailable proteolysis-targeting chimera (PROTAC) degrader of mSWI/SNF ATPases (SMARCA2 and SMARCA4) and PBRM1. AU-24118 demonstrated tumor regression in a model of castration-resistant prostate cancer (CRPC) which was further enhanced with combination enzalutamide treatment, a standard of care androgen receptor (AR) antagonist used in CRPC patients.

View Article and Find Full Text PDF

Mammalian switch/sucrose non-fermentable (mSWI/SNF) ATPase degraders have been shown to be effective in enhancer-driven cancers by functioning to impede oncogenic transcription factor chromatin accessibility. Here, we developed AU-24118, a first-in-class, orally bioavailable proteolysis targeting chimera (PROTAC) degrader of mSWI/SNF ATPases (SMARCA2 and SMARCA4) and PBRM1. AU-24118 demonstrated tumor regression in a model of castration-resistant prostate cancer (CRPC) which was further enhanced with combination enzalutamide treatment, a standard of care androgen receptor (AR) antagonist used in CRPC patients.

View Article and Find Full Text PDF

The POU2F3-POU2AF2/3 (OCA-T1/2) transcription factor complex is the master regulator of the tuft cell lineage and tuft cell-like small cell lung cancer (SCLC). Here, we found that the POU2F3 molecular subtype of SCLC (SCLC-P) exhibits an exquisite dependence on the activity of the mammalian switch/sucrose non-fermentable (mSWI/SNF) chromatin remodeling complex. SCLC-P cell lines were sensitive to nanomolar levels of a mSWI/SNF ATPase proteolysis targeting chimera (PROTAC) degrader when compared to other molecular subtypes of SCLC.

View Article and Find Full Text PDF

Background: Targeted therapies like vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) are the first-choice treatment in several types of cancers. We aim to determine the comparative risk of bleeding events associated with the VEGFR-TKIs through a network meta-analysis.

Methods: Published data search up to November 2018 reporting bleeding in cancer patients treated with VEGFR-TKIs was performed.

View Article and Find Full Text PDF

Purpose: Retinal nerve fibre layer (RNFL) is a sensitive structure, which is affected by anaemia due to hypoxia. A timely detection of RNFL thinning may aid preventing devastating complications. Optical coherence tomography (OCT) measures RNFL thinning with accuracy and helps in detecting thinning of the retinal layer in anaemic patients.

View Article and Find Full Text PDF