Publications by authors named "Rakesh S Nair"

The oncoimmunology research has witnessed notable advancements in recent years. Reshaping the tumor microenvironment (TME) approach is an effective method to improve antitumor immune response. The T cell-mediated antitumor response is crucial for favorable therapeutic outcomes in several cancers.

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Article Synopsis
  • The study investigates the role of β-hCG in breast cancer, particularly in Breast Invasive Carcinoma (BRCA), assessing its gene expression and implications for clinical outcomes.
  • Data from various gene expression databases and laboratory techniques were used to analyze β-hCG levels, particularly focusing on its connection to BRCA1 mutations and immune cell presence in tumors.
  • Results indicate that β-hCG is upregulated in breast cancers with BRCA1 mutations, suggesting it could serve as a potential target for treatment in BRCA1-deficient patients.
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Triple-negative breast cancer (TNBC) is difficult to treat breast cancer subtype due to lack or insignificant expressions of targetable estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2). Therefore, finding a targetable protein or signaling pathway in TNBC would impact patient care. Here, we report that a member of the Mixed Lineage Kinase (MLK) family, MLK3, is an effector of G-protein-coupled protease-activated receptors 1 (PAR1) and targeting MLK3 by a small-molecule inhibitor prevented PAR1-mediated TNBC tumorigenesis.

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Advanced hepatocellular carcinoma (HCC) is a lethal disease, with limited therapeutic options. Mixed Lineage Kinase 3 (MLK3) is a key regulator of liver diseases, although its role in HCC remains unclear. Analysis of TCGA databases suggested elevated MAP3K11 (MLK3 gene) expression, and TMA studies showed higher MLK3 activation in human HCCs.

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Missense mutations in the RAS family of oncogenes (HRAS, KRAS, and NRAS) are present in approximately 20% of human cancers, making RAS a valuable therapeutic target (Prior et al., Cancer Res 80:2969-2974, 2020). Although decades of research efforts to develop therapeutic inhibitors of RAS were unsuccessful, there has been success in recent years with the entrance of FDA-approved KRAS-specific inhibitors to the clinic (Skoulidis et al.

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Mixed Lineage Kinase 3 (MLK3) is a viable target for neoplastic diseases; however, it is unclear whether its activators or inhibitors can act as anti-neoplastic agents. We reported that the MLK3 kinase activity was higher in triple-negative (TNBC) than in hormone receptor-positive human breast tumors, where estrogen inhibited MLK3 kinase activity and provided a survival advantage to ER breast cancer cells. Herein, we show that in TNBC, the higher MLK3 kinase activity paradoxically promotes cancer cell survival.

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Trastuzumab is the first-line therapy for human epidermal growth factor receptor 2-positive (HER2) breast cancer, but often patients develop acquired resistance. Although other agents are in clinical use to treat trastuzumab-resistant (TR) breast cancer; still, the patients develop recurrent metastatic disease. One of the primary mechanisms of acquired resistance is the shedding/loss of the HER2 extracellular domain, where trastuzumab binds.

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MAP4K4 is a Ste20 member and reported to play important roles in various pathologies, including in cancer. However, the mechanism by which MAP4K4 promotes pancreatic cancer is not fully understood. It is suggested that MAP4K4 might function as a cancer promoter via specific downstream target(s) in an organ-specific manner.

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The transcription factor Glioma-Associated Oncogene Homolog 1 (GLI1) is activated by sonic hedgehog (SHH) cascade and is an established driver of pancreatic ductal adenocarcinoma (PDAC). However, therapies targeting upstream hedgehog signaling have shown little to no efficacy in clinical trials. Here, we identify Mixed Lineage Kinase 3 (MLK3) as a druggable regulator of oncogenic GLI1.

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Aberrant activation of Wnt/-catenin axis occurs in several gastrointestinal malignancies due to inactivating mutations of adenomatous polyposis coli (in colorectal cancer) or activating mutations of -catenin itself [in hepatocellular carcinoma (HCC)]. These lead to -catenin stabilization, increase in -catenin/T-cell factor (TCF)-mediated transcriptional activation, and target gene expression, many of which are involved in tumor progression. While studying pharmaceutical agents that can target -catenin in cancer cells, we observed that the plant compound berberine (BBR), a potent activator of AMP-activated protein kinase (AMPK), can reduce -catenin expression and downstream signaling in HCC cells in a dose-dependent manner.

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Article Synopsis
  • The study investigates the role of Mixed Lineage Kinase 3 (MLK3) in CD8 T cell survival and function, focusing on its potential as a target for cancer therapy.
  • Researchers used flow cytometry and RT PCR to analyze T cell phenotypes and apoptosis, discovering that inhibiting MLK3 leads to increased apoptosis in CD8 T cells through a CD70-TNFα-TNFRSF1a pathway.
  • The findings suggest that blocking CD70 can enhance CD8 T cell function and infiltration in breast cancer models, indicating that MLK3 is crucial for maintaining CD8 T cell survival and effectiveness.
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Mixed lineage kinase 3 (MLK3), also known as MAP3K11, was initially identified in a megakaryocytic cell line and is an emerging therapeutic target in cancer, yet its role in immune cells is not known. Here, we report that loss or pharmacological inhibition of MLK3 promotes activation and cytotoxicity of T cells. MLK3 is abundantly expressed in T cells, and its loss alters serum chemokines, cytokines, and CD28 protein expression on T cells and its subsets.

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The original version of this Article did not acknowledge Pradeep Sathyanarayana as an author. His affiliation is Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, Maine, USA.

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β-hCG expression in breast cancer is highly controversial with reports supporting both protective and tumorigenic effects. It has also been reported that risk of breast cancer at an early age is increased with full-term pregnancies if a woman is a BRCA1 mutation carrier. We have already demonstrated that BRCA1-defective cells express high levels of β-hCG and that when BRCA1 is restored, β-hCG level is reduced.

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Mixed lineage kinase 3 (MLK3), a MAP3K member has been envisioned as a viable drug target in cancer, yet its detailed function and signaling is not fully elucidated. We identified that MLK3 tightly associates with an oncogene, PAK1. Mammalian PAK1 being a Ste20 (MAP4K) member, we tested whether it is an upstream regulator of MLK3.

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Mixed Lineage Kinase 3 (MLK3), also called as MAP3K11 is a tightly regulated MAP3K member but its cellular function is still not fully understood. Earlier we reported post-translational regulation of MLK3 by estrogen (E2) that inhibited the kinase activity and favored survival of ER+ breast cancer cells. Here we report that MLK3 is also transcriptionally downregulated by E2 in ER+ breast cancer cells.

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Novel chelated metal complexes were synthesized from carbohydrazones to thiocarbohydrazones using metal-based drug designing platforms and their combination effect with Pb, a naphthaquinone were analyzed for anticancer activity in breast cancer cell lines. A panel of BRCA1 wild-type and mutated breast cancer cells: MCF-7 (BRCA1 /ER ), MDA-MB-231 (BRCA1 /ERα ), HCC-1937 (BRCA1 /ERα ), HCC1937/wt BRCA1, MX1 (BRCA1 /ERα ), and MDA-MB-436 (BRCA1 /ERα ) were screened for anti-cancer activity. Cu (HL)(HSO ) · H O]SO  · 6 H O (CS2) is the most potent anticancer agent among the copper carbohydrazone and thiocarbohydrazone complexes analyzed in this study.

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We have earlier shown that Plumbagin (PB) can induce selective cytotoxicity to BRCA1 defective ovarian cancer cells; however, the effect of this molecule in BRCA1 mutated breast cancers has not been analyzed yet. Here, we report that reactive oxygen species (ROS) induced by PB resulted in DNA DSB and activates downstream signaling by ATR/ATM kinases and subsequent apoptosis. PB reduces DNA- dependent protein kinase (DNA-PK) expression and inhibits NHEJ (Non Homologous End Joining) activity in BRCA1 defective breast cancer cells.

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Eventhough the role of BRCA1/2 in hereditary prostatic cancer is being unleashed at a rapid rate; their optimal clinical management remains undefined. Cancer stem cells are thought to be responsible for cancer chemoresistance and relapse, thus they represent a significant concern for cancer prognosis and therapy. In this study, we have analyzed the effect of Plumbagin (PB) and structurally related naphthaquinones on BRCA1/2 silenced prostate cancer cells and the ability of PB to target stem cells.

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Human epidermal growth factor receptor 2 (HER2) is amplified in ∼ 15-20% of human breast cancer and is important for tumor etiology and therapeutic options of breast cancer. Up-regulation of HER2 oncogene initiates cascades of events cumulating to the stimulation of transforming PI3K/AKT signaling, which also plays a dominant role in supporting cell survival and efficacy of HER2-directed therapies. Although investigating the underlying mechanisms by which HER2 promotes cell survival, we noticed a profound reduction in the kinase activity of a pro-apoptotic mixed lineage kinase 3 (MLK3) in HER2-positive (HER2+) but not in HER2-negative (HER2-) breast cancer tissues, whereas both HER2+ and HER2- tumors expressed a comparable level of MLK3 protein.

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Aims: Hydrazones belonging to the class of NNO donor Schiff bases are reported to have extensive anti-viral activity and anti-neoplastic activity against certain cancers such as colon cancer, hepatocellular carcinoma and testicular cancer. Here we aim to study the possible effects of two novel nicotinoyl hydrazones on Human papillomavirus (HPV) infected cervical cancers.

Main Methods: The effect of vanadium complexes on the proliferation of SiHa and HeLa cells was analyzed using MTT assay.

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It has been shown earlier that plumbagin, a naturally occurring naphthaquinone has specific anticancer activity in BRCA1 blocked ovarian cancer cells. Plumbagin can induce estrogen dependent cell signaling and apoptosis in BRCA1 blocked ovarian cancer cells. Being a reactive oxygen species (ROS) generator and apoptosis inducing agent, plumbagin has immense potential as a promising anticancer agent.

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Aloe emodin (AE), a natural anthraquinone, is reported to have antiproliferative activity in various cancer cell lines. In this study we analyzed molecular mechanisms involved in the antimigratory and antiangiogenic activity of this hydroxy anthraquinone in colon cancer cell, WiDr. Our results show that a relatively non toxic concentration of AE suppressed the phorbol-12-myristyl-13-acetate (PMA) induced migration and invasion of tumor cells.

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It has been reported that Breast Cancer Susceptibility gene-1 & 2 (BRCA1 & 2 are potential molecular targets for chemoprevention by isoflavone genistein (4' 5, 7-trihydroxy isoflavone), in breast and prostate cancer cells. It is also known that BRCA1 has inhibitory activity on estrogen receptor-alpha and genistein's action on cells is mainly through modulation of estrogen receptor activity. The action of genistein with respect to BRCA1 status in ovarian cancer cells has not been reported so far.

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