Biology subjects

Thillaiyampalam, G.

Publications and source records attributed to Thillaiyampalam, G..

3 recordsLinked to original sources

bioRxiv2025

Targeting FOXA1 and FOXA2 Disrupts the Lineage-Specific Oncogenic Output Program in Prostate Cancer

Activation of the androgen receptor (AR) is the key lineage-specific oncogenic pathway and the primary therapeutic target in prostate cancer. While AR signaling is enabled by the pioneer transcription factor FOXA1, its homolog FOXA2 is specifically expressed in advanced lineage plasticity prostate cancers that have lost the AR signaling axis. However, their roles and utility as drug targets remain incompletely characterized. Here, we show an unexpected collaboration of FOXA1 and FOXA2 in mediating AR-independent cell proliferation in different lineage plasticity cancer subtypes. Conversely, joint loss-of-function or pharmacologic disruption of FOXA1 and FOXA2 leads to the collapse of lineage-specific oncogenic transcription factors followed by cell cycle arrest. In summary, our findings uncover a druggable dependency for AR-positive and - negative prostate cancers.

cancer biology↗

bioRxiv2023

The IRE1α-endonuclease regulates PD-1 expression through a novel XBP1/miRNA-34a axis within Natural Killer cells

Activation of the IRE1-endonuclease is critical for Natural Killer (NK)-cell function. We describe a novel regulatory role for IRE1-endonuclease in fine-tuning NK-cell effector functions through an inter-connected activation of the transcription factor XBP1s and inhibition of microRNA-34a-5p (miR-34a-5p) to modulate PD-1 immune checkpoint expression. NK-cells, when exposed to cancer cells, activate IRE1-endonuclease mediated decay of miR-34a-5p. This reduces miR-34a-5p and consequently increases the expression of the target genes XBP1 and PD-1. IRE1-endonuclease activation not only enhances NK-cell effector function but also promotes PD-1 expression. PD-1 is itself directly regulated by miR-34a-5p, which binds to the 3UTR of PD-1 messenger RNA to repress PD-1 protein at the NK-cell surface. IRE1-pathway activation is impaired in the NK-cells of patients with Hodgkin Lymphoma, and miR-34a-5p and PD-1 expression are inversely correlated. The IRE1-pathway plays a dual role in regulating the XBP1/miRNA-34a axis and PD-1 expression within NK-cells, that is disrupted in cancer patients.

cancer biology↗

bioRxiv2022

An Alzheimer's disease patient-derived olfactory cell model identifies gene expression changes associated with cognition

An early symptom of Alzheimers disease (AD) is an impaired sense of smell, for which the molecular basis remains elusive. Here, we generated human olfactory neurosphere-derived (ONS) cells from people with AD and mild cognitive impairment (MCI), and performed global RNA sequencing to determine gene expression changes. ONS cells expressed markers of neuroglial differentiation, providing a unique cellular model to explore early AD-associated disease pathways. Our transcriptomics data from ONS cells revealed differentially expressed genes (DEGs) associated with cognitive processes in AD cells compared to MCI, or matched healthy controls (HC). A-Kinase Anchoring Protein 6 (AKAP6) was the most significantly altered gene in AD compared to both MCI and HC, and has been linked to cognitive function. The greatest change in gene expression of all DEGs occurred between AD and MCI. Gene pathway analysis revealed defects in multiple cellular processes with aging, intellectual deficiency and alternative splicing being the most significantly dysregulated in AD ONS cells. Our results demonstrate that ONS cells can provide a cellular model for AD that recapitulates disease-associated differences. We have revealed potential novel genes, including AKAP6 that may have a role in AD, particularly MCI to AD transition, and should be further examined.

neuroscience↗