Microrchidia 2/histone deacetylase 1 complex regulates E-cadherin gene expression and function.

Although Microrchidia 2 (MORC2) is widely overexpressed in human malignancies and linked to cancer cell proliferation, metabolism, and metastasis, the mechanism of action of MORC2 in cancer cell migration and invasion is yet undeciphered. Here, we identified for the first time that MORC2, a chromatin remodeler, regulates E-cadherin expression and, subsequently regulates breast cancer cell migration and invasion. We observed a negative correlation between the expression levels of MORC2 and E-cadherin in breast cancer. Furthermore, the overexpression of MORC2 resulted in decreased expression levels of E-cadherin. In addition, co-immunoprecipitation and chromatin immunoprecipitation assays revealed that MORC2 interacts with HDAC1 and gets recruited onto the E-cadherin promoter to inhibit its transcription, thereby suppress its expression. Consequently, knockdown of HDAC1 in MORC2-overexpressing cells led to reduced cancer cell migration and invasion. Interestingly, we noticed that MORC2-regulated glucose metabolism via c-Myc, and LDHA, also modulates the expression of E-cadherin. Collectively, these results demonstrate for the first time a mechanistic role for MORC2 as an upstream regulator of E-cadherin expression and its associated functions in breast cancer.

MORC2 and MAX contributes to the expression of glycolytic enzymes, breast cancer cell proliferation and migration.

Cancer cell proliferation is a high energy demanding process, where the cancer cells acquire energy by high rates of glycolysis, and this phenomenon is known as the "Warburg effect". Microrchidia 2 (MORC2), an emerging chromatin remodeler, is over expressed in several cancers including breast cancer and found to promote cancer cell proliferation. However, the role of MORC2 in glucose metabolism in cancer cells remains unexplored. In this study, we report that MORC2 interacts indirectly with the genes involved in glucose metabolism via transcription factors MAX (MYC-associated factor X) and MYC. We also found that MORC2 co-localizes and interacts with MAX. Further, we observed a positive correlation of expression of MORC2 with glycolytic enzymes Hexokinase 1 (HK1), Lactate dehydrogenase A (LDHA) and Phosphofructokinase platelet (PFKP) type in multiple cancers. Surprisingly, the knockdown of either MORC2 or MAX not only decreased the expression of glycolytic enzymes but also inhibited breast cancer cell proliferation and migration. Together, these results demonstrate the involvement of the MORC2/MAX signaling axis in the expression of glycolytic enzymes and breast cancer cell proliferation and migration.

MORC2/ß-catenin signaling axis promotes proliferation and migration of breast cancer cells.

Although Microrchidia 2 (MORC2) is overexpressed in many types of human cancer, its role in breast cancer progression remains unknown. Here, we report that the chromatin remodeler MORC2 expression positively correlates with ß-catenin expression in breast cancer cell lines and patients. Overexpression of MORC2 augmented the expression of ß-catenin and its target genes, cyclin D1 and c-Myc. Consistent with these results, we found MORC2 knockdown resulted in decreased expression of ß-catenin and its target genes. Surprisingly, we observed that c-Myc, the target gene of ß-catenin, regulated the MORC2-ß-catenin signaling axis through a feedback mechanism. We demonstrated that MORC2 regulates ß-catenin expression and function by modulating the phosphorylation of AKT. In addition, we observed reduced proliferation and migration of MORC2 overexpressing breast cancer cells upon ß-catenin inhibition. Overall, our results demonstrate that MORC2 promotes breast cancer cell proliferation and migration by regulating ß-catenin signaling.

Virtual screening of curcumin and its analogs against the spike surface glycoprotein of SARS-CoV-2 and SARS-CoV.

COVID-19, a new pandemic caused by SARS-CoV-2, was first identified in 2019 in Wuhan, China. The novel corona virus SARS-CoV-2 and the 2002 SARS-CoV have 74% identity and use similar mechanisms to gain entry into the cell. Both the viruses enter the host cell by binding of the viral spike glycoprotein to the host receptor, angiotensin converting enzyme 2 (ACE2). Targeting entry of the virus has a better advantage than inhibiting the later stages of the viral life cycle. The crystal structure of the SARS-CoV (6CRV: full length S protein) and SARS-CoV-2 Spike proteins (6M0J: Receptor binding domain, RBD) was used to determine potential small molecule inhibitors. Curcumin, a naturally occurring phytochemical in Curcuma longa, is known to have broad pharmacological properties. In the present study, curcumin and its derivatives were docked, using Autodock 4.2, onto the 6CRV and 6M0J to study their capability to act as inhibitors of the spike protein and thereby, viral entry. The curcumin and its derivatives displayed binding energies, ΔG, ranging from -10.98 to -5.12 kcal/mol (6CRV) and -10.01 to -5.33 kcal/mol (6M0J). The least binding energy was seen in bis-demethoxycurcumin with: ΔG = -10.98 kcal/mol (6CRV) and -10.01 kcal/mol (6M0J). A good binding energy, drug likeness and efficient pharmacokinetic parameters suggest the potential of curcumin and few of its derivatives as SARS-CoV-2 spike protein inhibitors. However, further research is necessary to investigate the ability of these compounds as viral entry inhibitors.Communicated by Ramaswamy H. Sarma.

The chromatin modifier MORC2 affects glucose metabolism by regulating the expression of lactate dehydrogenase A through a feed forward loop with c-Myc.

Microrchidia family CW-type zinc finger 2 (MORC2) is a recently identified chromatin modifier with an emerging role in cancer metastasis. However, its role in glucose metabolism, a hallmark of malignancy, remains to be explored. We found that MORC2 is a glucose-inducible gene and a target of c-Myc. Our meta-analysis revealed that MORC2 expression is positively correlated with the expression of enzymes involved in glucose metabolism in breast cancer patients. Furthermore, overexpression of MORC2 in MCF-7 and BT-549 cells augmented the expression and activity of a key glucose metabolism enzyme, lactate dehydrogenase A (LDHA). Conversely, selective knockdown of MORC2 by siRNA markedly decreased LDHA expression and activity and in turn reduced cancer cell migration. Collectively, these findings provide evidence that MORC2, a glucose-inducible gene, modulates the migration of breast cancer cells through the MORC2-c-Myc-LDHA axis.

MTA1 coregulator regulates LDHA expression and function in breast cancer.

Metastasis Associated Protein1 (MTA1) is a chromatin modifier and its expression is significantly associated with prognosis of many cancers. However, its role in glucose metabolism remains unexplored. Here, we report that MTA1 has a significant role in glucose metabolism where MTA1 regulates the LDHA expression and activity and subsequently its function in breast cancer motility. The results showed that MTA1 expression is positively correlated with the LDHA expression levels in breast cancer patients. Further, it was found that MTA1 is necessary for the optimal expression of LDHA. The underlying molecular mechanism involves the interaction of MTA1 with c-Myc and recruitment of MTA1-c-Myc complex on to the LDHA promoter to regulate its transcription. Consequently, the LDHA knock down using LDHA specific siRNA in MCF7 cells stably expressing MTA1 reduced the migration of MCF7 cells. Altogether these findings revealed the regulatory role for MTA1 in LDHA expression and its resulting biological function.

DenHunt - A Comprehensive Database of the Intricate Network of Dengue-Human Interactions.

Dengue virus (DENV) is a human pathogen and its etiology has been widely established. There are many interactions between DENV and human proteins that have been reported in literature. However, no publicly accessible resource for efficiently retrieving the information is yet available. In this study, we mined all publicly available dengue-human interactions that have been reported in the literature into a database called DenHunt. We retrieved 682 direct interactions of human proteins with dengue viral components, 382 indirect interactions and 4120 differentially expressed human genes in dengue infected cell lines and patients. We have illustrated the importance of DenHunt by mapping the dengue-human interactions on to the host interactome and observed that the virus targets multiple host functional complexes of important cellular processes such as metabolism, immune system and signaling pathways suggesting a potential role of these interactions in viral pathogenesis. We also observed that 7 percent of the dengue virus interacting human proteins are also associated with other infectious and non-infectious diseases. Finally, the understanding that comes from such analyses could be used to design better strategies to counteract the diseases caused by dengue virus. The whole dataset has been catalogued in a searchable database, called DenHunt (http://proline.biochem.iisc.ernet.in/DenHunt/).

Translational up-regulation and high-level protein expression from plasmid vectors by mTOR activation via different pathways in PC3 and 293T cells.

BACKGROUND: Though 293T cells are widely used for expression of proteins from transfected plasmid vectors, the molecular basis for the high-level expression is yet to be understood. We recently identified the prostate carcinoma cell line PC3 to be as efficient as 293T in protein expression. This study was undertaken to decipher the molecular basis of high-level expression in these two cell lines. METHODOLOGY/PRINCIPAL FINDINGS: In a survey of different cell lines for efficient expression of platelet-derived growth factor-B (PDGF-B), ß-galactosidase (ß-gal) and green fluorescent protein (GFP) from plasmid vectors, PC3 was found to express at 5-50-fold higher levels compared to the bone metastatic prostate carcinoma cell line PC3BM and many other cell lines. Further, the efficiency of transfection and level of expression of the reporters in PC3 were comparable to that in 293T. Comparative analyses revealed that the high level expression of the reporters in the two cell lines was due to increased translational efficiency. While phosphatidic acid (PA)-mediated activation of mTOR, as revealed by drastic reduction in reporter expression by n-butanol, primarily contributed to the high level expression in PC3, multiple pathways involving PA, PI3K/Akt and ERK1/2 appear to contribute to the abundant reporter expression in 293T. Thus the extent of translational up-regulation attained through the concerted activation of mTOR by multiple pathways in 293T could be achieved through its activation primarily by the PA pathway in PC3. CONCLUSIONS/SIGNIFICANCE: Our studies reveal that the high-level expression of proteins from plasmid vectors is effected by translational up-regulation through mTOR activation via different signaling pathways in the two cell lines and that PC3 is as efficient as 293T for recombinant protein expression. Further, PC3 offers an advantage in that the level of expression of the protein can be regulated by simple addition of n-butanol to the culture medium.