Recent Advances in Employment Practices across Industries in India

Employment practices liability is an area that deals with wrongful termination, sexual harassment, discrimination, invasion of privacy, false imprisonment, breach of contract, emotional distress, and wage and hour law violations.As one of the most promising future world markets, India attracts many workers from abroad. Thriving IT centers such as Bangalore, Madras or Hyderabad offers great career opportunities for expatriates.Working in India demonstrates the willingness to work in a new culture and international market. As India’s importance in world economy increases, work experience in this country will become increasingly profitable

A Comprehensive Corpus Callosum Segmentation Tool for Detecting Callosal Abnormalities and Genetic Associations from Multi Contrast MRIs

Structural alterations of the midsagittal corpus callosum (midCC) have been associated with a wide range of brain disorders. The midCC is visible on most MRI contrasts and in many acquisitions with a limited field-of-view. Here, we present an automated tool for segmenting and assessing the shape of the midCC from T1w, T2w, and FLAIR images. We train a UNet on images from multiple public datasets to obtain midCC segmentations. A quality control algorithm is also built-in, trained on the midCC shape features. We calculate intraclass correlations (ICC) and average Dice scores in a test-retest dataset to assess segmentation reliability. We test our segmentation on poor quality and partial brain scans. We highlight the biological significance of our extracted features using data from over 40,000 individuals from the UK Biobank; we classify clinically defined shape abnormalities and perform genetic analyses

PPM1D modulates hematopoietic cell fitness and response to DNA damage and is a therapeutic target in myeloid malignancy

PPM1D encodes a phosphatase that is recurrently activated across cancer, most notably in therapy-related myeloid neoplasms. However, the function of PPM1D in hematopoiesis and its contribution to tumor cell growth remain incompletely understood. Using conditional mouse models, we uncover a central role for Ppm1d in hematopoiesis and validate its potential as a therapeutic target. We find that Ppm1d regulates the competitive fitness and self-renewal of hematopoietic stem cells (HSCs) with and without exogenous genotoxic stresses. We also show that while Ppm1d activation confers cellular resistance to cytotoxic therapy, it does so to a lesser degree than p53 loss, informing the clonal competition phenotypes often observed in human studies. Notably, loss of Ppm1d sensitizes leukemias to cytotoxic therapies in vitro and in vivo, even in the absence of a Ppm1d mutation. Vulnerability to PPM1D inhibition is observed across many cancer types and dependent on p53 activity. Importantly, organism-wide loss of Ppm1d in adult mice is well tolerated, supporting the tolerability of pharmacologically targeting PPM1D. Our data link PPM1D gain-of-function mutations to the clonal expansion of HSCs, inform human genetic observations, and support the therapeutic targeting of PPM1D in cancer

Improved reference genome of Aedes aegypti informs arbovirus vector control

Female Aedes aegypti mosquitoes infect more than 400 million people each year with dangerous viral pathogens including dengue, yellow fever, Zika and chikungunya. Progress in understanding the biology of mosquitoes and developing the tools to fight them has been slowed by the lack of a high-quality genome assembly. Here we combine diverse technologies to produce the markedly improved, fully re-annotated AaegL5 genome assembly, and demonstrate how it accelerates mosquito science. We anchored physical and cytogenetic maps, doubled the number of known chemosensory ionotropic receptors that guide mosquitoes to human hosts and egg-laying sites, provided further insight into the size and composition of the sex-determining M locus, and revealed copy-number variation among glutathione S-transferase genes that are important for insecticide resistance. Using high-resolution quantitative trait locus and population genomic analyses, we mapped new candidates for dengue vector competence and insecticide resistance. AaegL5 will catalyse new biological insights and intervention strategies to fight this deadly disease vector

Therapy for B-cell Lymphoma

B-cell non-Hodgkin lymphoma (NHL) is the fifth most common cancer comprised of indolent and aggressive subtypes. Current therapeutic approaches result in short term survival, urging the development of better therapeutics. This dissertation involves design and evaluation of novel therapeutic approaches for the treatment of B-cell lymphomas. Primary effusion lymphoma (PEL), a rare form of aggressive NHL is caused by Kaposi’s sarcoma-associated herpesvirus (KSHV) and/or Epstein-barr virus (EBV). An attractive option for treating PEL and other γ-herpesvirus induced cancers is targeting endogenous latent viruses with drugs that reactivate their lytic replication, thereby eradicating virally-infected reservoirs. Here we demonstrate that the combination of proteasome inhibitor bortezomib (Btz) with the HDAC inhibitor, vorinostat (SAHA), potently reactivates KSHV lytic replication and induces PEL cell death resulting in significantly prolonged survival of PEL-bearing mice (p<0.001, compared to single agent). Importantly, Btz blocks KSHV late lytic gene expression thus terminally inhibiting the full lytic cascade and production of infectious virus in vivo. Btz also led to caspase activation, and induced DNA damage and in synergy with SAHA induces early acetylation of p53 resulting in reduced interaction with its negative regulator MDM2 to facilitate p53 stabilization. Consequently we propose the antineoplastic and lytic-inductive paradigm combining proteasome and HDAC inhibitors to eradicate KSHV-infected PEL without increased viremia. In a second targeting strategy, we first demonstrate that majority of PEL tumors express CD30 antigen, an attractive target for immunotherapy. Brentuximab vedotin, anti-CD30 monoclonal antibody conjugated to anti-mitotic agent is clinically approved for against CD30-expressing Hodgkin’s and systemic anaplastic large cell lymphomas. In our study we showed for the first time that brentuximab vedotin has anti-lymphoma activity against PEL. In vitro treatment with brentuximab vedotin decreases cell proliferation, induces cell cycle arrest and triggers apoptosis of PEL cell lines. Furthermore, in vivo brentuximab vedotin promotes tumor regression and prolongs survival of UM-PEL-1 as well as UM-PEL-3 xenograft mice. In third approach, we evaluated the anti-tumor potential of interleukin 21 (IL-21), in mantle cell lymphoma (MCL), a distinct subtype of NHL which is highly chemoresistant. IL-21 is a member of the IL-2 cytokine family, possesses potent anti-tumor activity against a variety of cancers not expressing IL-21 receptor (IL-21R) through activation of the immune system. Previously study from the lab has established that apart from immuno-stimulatory effects, IL-21 exerts direct cytotoxicity on IL-21R-expressing diffuse large B cell lymphoma cells (DLBCL). Here we found that IL-21 also possess potent cytotoxicity against MCL tumors. IL-21-induced direct cytotoxicity is mediated through STAT3-dependent cMyc upregulation resulting in activation of Bax and inhibition of Bcl-2 and Bcl-XL. Importantly, IL-21-mediated cMyc upregulation is only observed in IL-21-sensitive MCL cell lines and primary tumors. We also discover that IL-21 leads to NK-cell dependent lysis of the MCL cell lines that showed resistance to direct cytotoxicity and also demonstrate potent in vivo activity of IL-21 in MCL mouse model (FcmuMCL1). To further improve anti-tumor potential of IL-21, we designed a fusion protein comprising IL-21 linked to the N-terminus of anti-CD20 antibody (αCD20-IL-21 fusokine). We demonstrate that cytotoxic effects induced by αCD20-IL-21 fusokine in DLBCL and MCL cell lines and primary tumors markedly increase compared to its individual components (IL-21 and parent αCD20-IgG1 antibody). Importantly, fusokine treatment results into cell death of MCL cell lines that are found to be resistant to IL-21 alone treatment. Notably, αCD20-IL-21 fusokine has shown increased ADCC activity in comparison to parent antibody plus IL-21 in NHL cell lines and primary tumors. These data strongly suggest that together with direct apoptotic potential, αCD20- IL-21 fusokine retains the ability to trigger indirect cell killing via activation of immune effector cells. These dual effects may give remarkable advantage to the fusokine over existing anti-CD20 antibodies for the treatment of NHL tumors. Collectively, this dissertation demonstrates pre-clinical efficacy of novel therapeutic approaches for the treatment of B-cell lymphomas which is crucial for clinical intervention.</p

Dynamic BH3 profiling method for rapid identification of active therapy in BH3 mimetics resistant xenograft mouse models

Summary: The clinical effectiveness of BH3 mimetics therapy is limited by the inevitable emergence of acquired resistance. We present a protocol to model in vivo acquired resistance to BH3 mimetics in patient-derived xenograft (PDX) mouse models of acute myeloid leukemia. Using resistant PDXs as a valuable model, we next introduce a protocol for dynamic BH3 profiling (DBP) method. DBP allows functional identification of effective drug therapies based on measurements of drug-induced apoptosis signaling to overcome in vivo BH3 mimetics resistance.For complete details on the use and execution of this protocol, please refer to Bhatt et al. (2020)

Interleukin 21 - its potential role in the therapy of B-cell lymphomas

Interleukin-21 (IL-21), a member of IL-2 cytokine family, has pleotropic biological effects on lymphoid and myeloid cells. During the past 15 years, since the discovery of IL-21, great advances have been made regarding its biological activity and the mechanisms controlling IL-21-mediated cellular responses, especially in hematological malignancies. Preclinical studies have shown that IL-21R is expressed on healthy and neoplastic B-cells and exogenous IL-21 can induce direct apoptosis of IL-21R expressing B-cell non-Hodgkin lymphomas (NHL), making it a potentially attractive anti-lymphoma therapy. However, in some hematological malignancies such as multiple myeloma, Hodgkin lymphoma and Burkitt lymphoma, IL-21 can induce proliferation of neoplastic B-cells. In NHL, the underlying mechanism of cell death was found to be different between the various subtypes, including activation of different JAK/STAT signal transduction pathways or other factors. Immunomodulatory effects of IL-21 have also been reported to contribute to its anti-tumor effects as described by earlier studies in solid tumors and B-cell associated malignancies. These effects are predominantly mediated by IL-21's ability to activate cytolytic activities by NK-cells and CD4 + /CD8 + T-cells. In this review, we provide an overview of IL-21's effects in NHL, results from clinical trials utilizing IL-21, and propose how IL-21 can be therapeutically exploited for treating these lymphomas

Abstract LB-328: Preclinical activity of interleukin 21 in mantle cell lymphoma

Abstract Mantle cell lymphoma (MCL) is a distinct subtype of non-Hodgkin lymphoma characterized by overexpression of cyclin D1 (CCND1) in 95% of patients due to the t(11;14)(q13;q32) chromosomal translocation. This incurable lymphoma is highly chemoresistant with short duration response, frequent relapses and eventual death, even with the most aggressive chemotherapeutic regimens. Interleukin 21 (IL21), a member of the IL2 cytokine family, has shown anti-tumor effects in solid tumors, chronic lymphocytic leukemia (CLL) and diffuse large B-cell lymphoma (DLBCL) and it is currently in clinical trials for renal cell carcinoma and metastatic melanoma. Herein, we carried out a comprehensive study to delineate the effects of IL21 on MCL cell lines and primary tumors. Flow-cytometric analysis revealed that all MCL cell lines (Mino, HBL-2, Jeko-1, G-519, IRM-2, SP53, Z138, UPN1 and L-128) as well as primary tumors expressed surface IL21R at variable levels. Treatment of Mino, HBL-2 and SP53 cells with IL21 (100ng/mL) led to a marked time-dependent decrease in cell proliferation and increased cell death. In contrast, Jeko1, IRM2, L128, Z138, UPN1 and G519 cells exhibited resistance to IL21 treatment. Similarly, primary MCL tumors treated with IL21 in vitro exhibited significant cell death in 3 of 5 cases. To decipher the mechanism of IL21-induced apoptosis, responsive and resistant cell lines as well as primary tumors were utilized. Similarly to our previous study in DLBCL, IL21 stimulation resulted in dramatic phosphorylation of STAT1 and STAT3 in IL-21 responsive cell lines (Mino, HBL-2, SP53) and a primary tumor, while minimal phosphorylation of STAT5 was observed only in Mino. However, observed levels of phosphorylated STAT1, 3 and 5 were significantly lower in the resistant cells (Jeko-1) and primary tumor. We have previously demonstrated that IL21-induced cell death in DLBCL is mediated by STAT3-induced upregulation of c-Myc expression. Correspondingly, IL21 led to c-Myc upregulation in IL21-sensitive MCL cell lines and primary tumors. Strikingly, IL21 failed to induce c-Myc in the resistant cell line and primary tumor despite expressing similar level of IL21R. IL21 treatment also resulted in upregulation of the pro-apoptotic protein Bax and downregulation of the anti-apoptotic proteins Bcl-XL and Bcl2, as previously observed in DLBCL. Moreover, knockdown of STAT3, c-Myc or Bax using specific siRNAs in Mino cells resulted in abrogation of the IL21-induced cell death. In contrast to a previous report, knockdown of STAT1 did not prevent IL21-induced Mino cell death. Overall, these observations suggest that in vitro IL21 induces cell death and apoptosis in a subset of MCL cell lines and primary tumors by activating the STAT3-cMyc pathway and not through the STAT1 signaling pathway. Additionally, from our observations, MCL resistance to IL21 may be due to abolition of STAT3-c-Myc activation in response to IL21. Citation Format: Shruti Bhatt, Kristopher A. Sarosiek, Izidore S. Lossos. Preclinical activity of interleukin 21 in mantle cell lymphoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-328. doi:10.1158/1538-7445.AM2013-LB-32