Focal adhesion kinase confers lenvatinib resistance in hepatocellular carcinoma via the regulation of lysine-deficient kinase 1.

Lenvatinib is a clinically effective multikinase inhibitor approved for first-line therapy of advanced hepatocellular carcinoma (HCC). Although resistance against lenvatinib often emerges and limits its antitumor activity, the underlying molecular mechanisms involved in endogenous and acquired resistance remain elusive. In this study, we identified focal adhesion kinase (FAK) as a critical contributor to lenvatinib resistance in HCC. The elevated expression and phosphorylation of FAK were observed in both acquired and endogenous lenvatinib-resistant (LR) HCC cells. Furthermore, inhibition of FAK reversed lenvatinib resistance in vitro and in vivo. Mechanistically, FAK promoted lenvatinib resistance through regulating lysine-deficient kinase 1 (WNK1). Phosphorylation of WNK1 was significantly increased in LR-HCC cells. Further, WNK1 inhibitor WNK463 resensitized either established or endogenous LR-HCC cells to lenvatinib treatment. In addition, overexpression of WNK1 desensitized parental HCC cells to lenvatinib treatment. Conclusively, our results establish a crucial role and novel mechanism of FAK in lenvatinib resistance and suggest that targeting the FAK/WNK1 axis is a promising therapeutic strategy in HCC patients showing lenvatinib resistance.

Erythropoietin mitigated thioacetamide-induced renal injury via JAK2/STAT5 and AMPK pathway.

The kidney flushes out toxic substances and metabolic waste products, and homeostasis is maintained owing to the kidney efforts. Unfortunately, kidney disease is one of the illnesses with a poor prognosis and a high death rate. The current investigation was set out to assess erythropoietin (EPO) potential therapeutic benefits against thioacetamide (TAA)-induced kidney injury in rats. EPO treatment improved kidney functions, ameliorated serum urea, creatinine, and malondialdehyde, increased renal levels of reduced glutathione, and slowed the rise of JAK2, STAT5, AMPK, and their phosphorylated forms induced by TAA. EPO treatment also greatly suppressed JAK2, Phosphatidylinositol 3-kinases, and The Protein Kinase R-like ER Kinase gene expressions and mitigated the histopathological alterations brought on by TAA toxicity. EPO antioxidant and anti-inflammatory properties protected TAA-damaged kidneys. EPO regulates AMPK, JAK2/STAT5, and pro-inflammatory mediator synthesis.

Platelets' morphology, metabolic profile, exocytosis, and heterotypic aggregation with leukocytes in relation to severity and mortality of COVID-19-patients.

Roles of platelets during infections surpass the classical thrombus function and are now known to modulate innate immune cells. Leukocyte-platelet aggregations and activation-induced secretome are among factors recently gaining interest but little is known about their interplay with severity and mortality during the course of SARS-Cov-2 infection. The aim of the present work is to follow platelets' bioenergetics, redox balance, and calcium homeostasis as regulators of leukocyte-platelet interactions in a cohort of COVID-19 patients with variable clinical severity and mortality outcomes. We investigated COVID-19 infection-related changes in platelet counts, activation, morphology (by flow cytometry and electron microscopy), bioenergetics (by Seahorse analyzer), mitochondria function (by high resolution respirometry), intracellular calcium (by flow cytometry), reactive oxygen species (ROS, by flow cytometry), and leukocyte-platelet aggregates (by flow cytometry) in non-intensive care unit (ICU) hospitalized COVID-19 patients (Non-ICU, n=15), ICU-survivors of severe COVID-19 (ICU-S, n=35), non-survivors of severe COVID-19 (ICU-NS, n=60) relative to control subjects (n=31). Additionally, molecular studies were carried out to follow gene and protein expressions of mitochondrial electron transport chain complexes (ETC) in representative samples of isolated platelets from the studied groups. Our results revealed that COVID-19 infection leads to global metabolic depression especially in severe patients despite the lack of significant impacts on levels of mitochondrial ETC genes and proteins. We also report that severe patients' platelets exhibit hyperpolarized mitochondria and significantly lowered intracellular calcium, concomitantly with increased aggregations with neutrophil. These changes were associated with increased populations of giant platelets and morphological transformations usually correlated with platelets activation and inflammatory signatures, but with impaired exocytosis. Our data suggest that hyperactive platelets with impaired exocytosis may be integral parts in the pathophysiology dictating severity and mortality in COVID-19 patients.

Targeting CDC7 sensitizes resistance melanoma cells to BRAFV600E-specific inhibitor by blocking the CDC7/MCM2-7 pathway.

Although the utilization of selective BRAFV600E inhibitors is associated with improved overall survival in patients with metastatic melanoma, a growing challenge of drug resistance has  emerged. CDC7 has been shown to be overexpressed and associated with poor prognosis in various cancers including melanoma. Thus, we aimed to elucidate the biological role of CDC7 in promoting Vemurafenib resistance and the anticipated benefits of dual targeting of BRAFV600E and CDC7 in melanoma cells. We performed exosomes-associated microRNA profiling and functional assays to determine the role of CDC7 in drug resistance using Vemurafenib-sensitive and resistant melanoma cells. Our results demonstrated that Vemurafenib-resistant cells exhibited a persistent expression of CDC7 in addition to prolonged activity of MCM2 compared to drug-sensitive cells. Reconstitution of miR-3613-3p in resistant cells downregulated CDC7 expression and reduced the number of colonies. Treatment of cells with low concentrations of CDC7 inhibitor TAK-931 sensitized resistant cells to Vemurafenib and reduced the number of cell colonies. Taken together, CDC7 overexpression and downregulation of miR-3613-3p were associated with Vemurafenib resistance in BRAFV600E- bearing melanoma cells. Dual targeting of CDC7 and BRAFV600E reduced the development of resistance against Vemurafenib. Further studies are warranted to investigate the clinical effect of targeting CDC7 in metastatic melanoma.

Dysregulated gene expression predicts tumor aggressiveness in African-American prostate cancer patients.

Molecular mechanisms underlying the health disparity of prostate cancer (PCa) have not been fully determined. In this study, we applied bioinformatic approach to identify and validate dysregulated genes associated with tumor aggressiveness in African American (AA) compared to Caucasian American (CA) men with PCa. We retrieved and analyzed microarray data from 619 PCa patients, 412 AA and 207 CA, and we validated these genes in tumor tissues and cell lines by Real-Time PCR, Western blot, immunocytochemistry (ICC) and immunohistochemistry (IHC) analyses. We identified 362 differentially expressed genes in AA men and involved in regulating signaling pathways associated with tumor aggressiveness. In PCa tissues and cells, NKX3.1, APPL2, TPD52, LTC4S, ALDH1A3 and AMD1 transcripts were significantly upregulated (p < 0.05) compared to normal cells. IHC confirmed the overexpression of TPD52 (p = 0.0098) and LTC4S (p < 0.0005) in AA compared to CA men. ICC and Western blot analyses additionally corroborated this observation in PCa cells. These findings suggest that dysregulation of transcripts in PCa may drive the disparity of PCa outcomes and provide new insights into development of new therapeutic agents against aggressive tumors. More studies are warranted to investigate the clinical significance of these dysregulated genes in promoting the oncogenic pathways in AA men.