Nidhi Singh

Prostate cancer (CaP) remains a major cause of cancer death in men, underscoring the need for mechanistically novel therapies. We previously identified the action of the mitotic kinase citron (CIT) kinase as a key driver of CaP progression and promising therapeutic target, but selective CIT inhibitors are not available. We therefore asked whether a better understanding of the action of CIT substrates, which execute CIT kinase action in CaP cells, can lead to novel approaches and/or alternative targets to indirectly interfere with CIT’s activity during CaP progression. In view of the enrichment in functions in alternative splicing among CIT substrates, we focus on the RNA splicing regulator THRAP3 as a representative substrate. Direct THRAP3 phosphorylation by CIT determined THRAP3’s RNA binding to CIT-controlled pre–messenger RNA targets. Cross-linking and immunoprecipitation sequencing identified a subset of CIT-dependent THRAP3-bound genes that were preferentially involved in cell proliferation. THRAP3 RNA binding was enriched in genes that undergo alternative splicing during CaP progression. CIT-dependent THRAP3-bound transcripts stimulated the growth of CaP cell lines, xenografts, patient-derived organoids, and patient-derived xenograft (PDX)–derived organoids, whereas CIT-independent THRAP3-bound transcripts from the same gene did not. An antisense oligo that blocks THRAP3’s recruitment to a CIT-dependent RNA binding site prevented the production of CIT- and THRAP3-dependent transcripts and inhibited the growth of cell lines and PDX-derived organoids representing different CaP stages and lineages but not of benign cells. Thus, CIT-mediated alternative splicing drives CaP progression, and its inhibition is a new therapeutic strategy in treatment-resistant CaP.

Prostate cancer remains the second leading cause of cancer death in men in Western cultures. A deeper understanding of the mechanisms by which prostate cancer cells divide to support tumor growth could help devise strategies to overcome treatment resistance and improve survival. Here, we identified that the mitotic AGC family protein kinase citron kinase (CIT) is a pivotal regulator of prostate cancer growth that mediates prostate cancer cell interphase progression. Increased CIT expression correlated with prostate cancer growth induction and aggressive prostate cancer progression, and CIT was overexpressed in prostate cancer compared with benign prostate tissue. CIT overexpression was controlled by an E2F2–Skp2–p27 signaling axis and conferred resistance to androgen-targeted treatment strategies. The effects of CIT relied entirely on its kinase activity. Conversely, CIT silencing inhibited the growth of cell lines and xenografts representing different stages of prostate cancer progression and treatment resistance but did not affect benign epithelial prostate cells or nonprostatic normal cells, indicating a potential therapeutic window for CIT inhibition. CIT kinase activity was identified as druggable and was potently inhibited by the multikinase inhibitor OTS-167, which decreased the proliferation of treatment-resistant prostate cancer cells and patient-derived organoids. Isolation of the in vivo CIT substrates identified proteins involved in diverse cellular functions ranging from proliferation to alternative splicing events that are enriched in treatment-resistant prostate cancer. These findings provide insights into the regulation of aggressive prostate cancer cell behavior by CIT and identify CIT as a functionally diverse and druggable driver of prostate cancer progression.Significance: The poorly characterized protein kinase citron kinase is a therapeutic target in prostate cancer that drives tumor growth by regulating diverse substrates, which control several hallmarks of aggressive prostate cancer progression.See related commentary by Mishra et al., p. 4008

Introduction: Even in a tertiary health-care setting, obstructive sleep apnea (OSA) patients often remain underdiagnosed. OSA and metabolic syndrome (MS) share many essential cardiovascular risk factors, including obesity, hypertension, and insulin resistance. Despite numerous studies, the relationship between OSA and MS still remains debatable. Aim: The purpose of our study was to see how frequently MS occurred in OSA patients and also if the presence of MS had any correlation with age, sex, or severity of OSA. Methodology: This cross-sectional study included 50 OSA patients being evaluated on outpatient department basis. All the patients were screened with detailed history; examination; hematological, biochemical parameters; and polysomnography. Results: In this study, out of 50 OSA patients, 41 were male and 9 were female; with age, body mass index (BMI), Apnea–Hypopnea Index (AHI), neck circumference, and waist circumference having mean of 42.5 years, 27.028 kg/m², 33.49/h, 39.7 cm, and 37.23 inch, respectively. Out of 28 obese patients, 22 had AHI >30 and 6 had AHI P = 0.01). Conclusion: Our study has shown a positive association between OSA and MS and OSA may represent an important risk factor for development of MS. Therefore, it is prudent for clinicians to systematically evaluate the presence of metabolic abnormalities in OSA patients and vice versa.

We aimed to evaluate the significance of the RANTES‐CCR5 axis and resulting immunomodulatory status in Dengue pathogenesis involving a Guwahati, India based population where Dengue cases have increased alarmingly. An increased CC‐chemokine receptor type 5 (CCR5) messenger RNA expression and CCR5 positive cell count profile was observed in Dengue cases, the highest being in severe cases. CCR5 ligand RANTES expression was significantly decreased in Dengue cases and inversely correlated with Dengue viremia fold change in severe cases. Monocytes are involved in Dengue virus homing and replication. Its levels and activation profile were higher in Dengue cases. A hyper Th1‐biased immunomodulatory profile with upregulated tumor necrosis factor‐α levels, and downregulated expression of antiviral cytokine interferon‐γ and key regulatory Th2 anti‐inflammatory cytokine interleukin 10 was observed in severe Dengue cases compared with mild Dengue cases and controls. The results, therefore, suggest the significance of RANTES‐CCR5 axis deregulation and resulting altered immunomodulation in Dengue pathogenesis, and holds prognostic and therapeutic significance.

Gallbladder cancer (GBC) is a fatal condition with dismal prognosis and aggressive local invasiveness; and with uncharacterised molecular pathology relating to non-specific therapeutic modalities. Given the importance of oxidative stress in chronic diseases and carcinogenesis, and the lacunae in literature regarding its role in gallbladder diseases, this study aimed to study the involvement of oxidative stress and deregulation in the base excision repair (BER) pathway in the pathogenesis of gallbladder diseases including GBC. This study involved patients from the North-East Indian population, where the numbers of reported cases are increasing rapidly and alarmingly. Oxidative stress, based on 8-OH-dG levels, was found to be significantly higher in gallbladder anomalies (cholelithiasis [CL] and cholecystitis [CS]) and GBC at the plasma and DNA level, and was associated with GBC severity. The expressions of key BER pathway genes were downregulated in gallbladder anomalies and GBC compared to controls, and in GBC compared to both non-neoplastic controls and gallbladder anomalies. Expression of XRCC1 and hOGG1 was significantly associated with both susceptibility and severity of GBC. The XRCC1 codon280 polymorphism was associated with disease susceptibility; and significantly higher oxidative stress was observed in hOGG1 genotypic variants. The genomes of GBC patients were found to be more hypermethylated compared to controls, with the promoters of XRCC1 and hOGG1 being hypermethylated and, therefore, being silenced. This study underlined the prognostic significance of the oxidative stress marker 8-OH-dG and BER pathway genes, especially hOGG1 and XRCC1, in gallbladder anomalies and GBC, as well as stated their potential for therapeutic targeting.

A genomewide transcriptome assay of two subtropical genotypes of maize was used to observe the expression of genes at seedling stage of drought stress. The number of genes expressed differentially was greater in HKI1532 (a drought tolerant genotype) than in PC3 (a drought sensitive genotype), indicating primary differences at the transcriptional level in stress tolerance. The global coexpression networks of the two genotypes differed significantly with respect to the number of modules and the coexpression pattern within the modules. A total of 174 drought-responsive genes were selected from HKI1532, and their coexpression network revealed key correlations between different adaptive pathways, each cluster of the network representing a specific biological function. Transcription factors related to ABA-dependent stomatal closure, signalling, and phosphoprotein cascades work in concert to compensate for reduced photosynthesis. Under stress, water balance was maintained by coexpression of the genes involved in osmotic adjustments and transporter proteins. Metabolism was maintained by the coexpression of genes involved in cell wall modification and protein and lipid metabolism. The interaction of genes involved in crucial biological functions during stress was identified and the results will be useful in targeting important gene interactions to understand drought tolerance in greater detail.

Gallbladder carcinoma (GBC) has been stated as an Indian disease, with the highest number of cases being reported from certain districts of northeast India, which has an ethnically distinct population. Unfortunately there are no scientific reports on the underlying molecular mechanisms associated with the pathogenesis of the disease from this region. The present study evaluated the role of differential expression of human telomerase reverse transcriptase (hTERT) in the development of gall bladder anomalies. Blood and tissue samples were collected from patients undergoing routine surgical resection for clinically proven cases of gallbladder disease {cholelithiasis (CL, n=50), cholecystitis (CS, n=40) and GBC (n=30) along with adjacent histopathologically proved non-neoplastic controls (n=15)} with informed consent. Whole blood was also collected from age and sex matched healthy controls (n=25) for comparative analysis. Differential hTERT mRNA expression was evaluated by semi-quantitative rt-PCR and real-time PCR based analysis using β-actin as an internal control. Evaluation of differential hTERT protein expression was studied by Western blot analysis and immunoflourescence. Statistical analysis for differential expression and co-relation was performed by SPSSv13.0 software. Gallbladder anomalies were mostly prevalent in females. The hTERT mRNA and protein expression increased gradiently from normal<CL<CS<GBC cases. Serum expression correlated statistically significantly with the tissue based mRNA expression pattern of hTERT, with highest expression observed in GBC cases and the lowest expression in normal gall bladder. Higher hTERT expression is associated with gallbladder disease susceptibility and severity; and may be a useful prognostic marker for gallbladder anomalies.