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Primary effusion lymphoma (PEL) is an aggressive form of non-Hodgkin lymphoma of B cells caused by Kaposi's Sarcoma-associated Herpes Virus (KSHV). KSHV encoded latent and lytic antigens promote oncogenic transformation and evade apoptosis through the modulation of various host cellular signaling pathways. Nm23-H1 is a known metastatic suppressor whose expression inversely correlates with the metastatic potential of different cancers. Here, we set out to assess the role of Nm23-H1 in PEL development.Flow cytometry and real-time PCR assays were performed for Nm23-H1 expression analysis. Induction of apoptosis was assessed using Western blotting and flow cytometry-based assays in Nm23-H1 overexpressing cells. Co-immunoprecipitation assays, confocal microscopy and imaging flow cytometry were performed to determine Nm23-H1 and vFLIP K13 protein-protein interaction. A PEL cell-induced xenograft model was established in non-obese diabetic/severely combined immunodeficient (NOD/SCID) mice to validate the effect of Nm23-H1 overexpression.We found that Nm23-H1 expression was significantly downregulated both at transcriptional and protein levels in PEL cell lines and that its overexpression triggered mitochondrial-mediated caspase-dependent apoptosis. We revealed Nm23-H1 interacts with the latent protein vFLIP K13 and that Nm23-H1 overexpression leads to inhibition of vFLIP K13 driven nuclear factor-kappa B (NF-κB) signaling with concurrent inhibition of autocrine and paracrine growth factors and downregulation of latent KSHV antigens without induction of active lytic reactivation. We also confirmed the effects of Nm23-H1 overexpression in a PEL cell-induced xenograft model in NOD/SCID mice.Downregulation of Nm23-H1 expression in KSHV-infected PEL cells and its overexpression trigger apoptosis by impairing vFLIP K13-driven NF-κB signaling, suggesting therapeutic implications of Nm23-H1 for primary effusion lymphomas.

A simple and efficient visible-light-induced methodology has been developed for the selective synthesis of dihydro-4H-furo[3,2-c]chromen-4-one derivatives via dehydrogenative coupling reaction. The methodology is highly useful for the synthesis of varieties of dihydro-4H-furo[3,2-c]chromen-4-ones from readily accessible reactants under oxygen atmosphere. Importantly, the additive-free approach has been also demonstrated for this transformation. The results of the mechanistic investigation showed that this dehydrogenative reaction proceeded through a radical pathway. Additionally, the synthesized dihydro-4H-furo[3,2-c]chromen-4-one has been transformed into different 4H-furo[3,2-c]chromen-4-ones through simple protocols.

1-Butane sulfonic acid-3-methylimidazolium tosylate, [BSMIM]OTs, is a remarkable catalyst for the cascade synthesis of coumarin-functionalized indole derivatives via a tandem cyclization reaction of aniline and phenylglyoxal monohydrate.

Background: The association of BAX -248 G>A and BCL2 -938 C>A with different cancers created conflicts. We studied the correlation and the effect of these polymorphisms in patients with Nasopharyngeal Carcinoma (NPC). Methods: PCR-RFLP and Sanger sequencing were used to detect polymorphisms. Statistical analysis including forest plot and Kaplan-Meier Log-rank test was conducted to investigate the association and effect of these SNPs on the NPC patients’ survival. The computational study was performed to investigate the possible regulatory role between these polymorphisms and the poor survival of NPC patients. Meta-analysis was executed to check the tissue-specific association of these polymorphisms in the context of global cancer prognosis. Results: We observed an increased and significant association of BAX -248 G>A [GA:OR=5.29, 95%CI=1.67,16.67, P=0.004; GA+AA:OR=5.71, 95%CI=1.82,17.90, P =0.002; A:OR=5.33, 95%CI=1.76,16.13, P=0.003], and BCL2 -938 C>A [CA:OR=2.26, 95%CI=1.03,4.96, P=0.04; AA:OR=3.56, 95%CI=0.97,13.05, P=0.05; CA+AA:OR=3.10, 95%CI=1.51,6.35, P=0.002; A:OR=2.90, 95% CI=1.59,5.29, P=0.0005] with the risk of NPC. Also, these SNPs were strongly correlated with poor survival in NPC patients (lower estimated survival mean, lower estimated proportion surviving at 5 years with pA showed a significant correlation with carcinomas [A vs G:OR=1.60, 95%CI=1.09,2.34, P=0.01; AA vs GG:OR=2.61, 95%CI=1.68,4.06, PA with other malignancies [A vs C:OR=1.45, 95%CI=1.26,1.66, PA and BCL2 -938 C>A was associated with poor survival in NPC patients. It may increase cancer susceptibility through transcriptional regulation. Moreover, these SNPs’ effects could be tissue-specific.

SARS-CoV-2, or novel coronavirus, is causing the fatal and contagious coronavirus disease-2019 (COVID-19) affecting thousands of people every single day. Researchers are continuously searching for any possible cure and/or vaccine, but no conclusive report is available till date. Like many others, we realize that a rapid, immediate, and elaborate strategy must be adopted to protect mankind. To avoid the time-loss due to clinical trials, we have performed in silico analyses on some FDA-approved drugs to combat COVID-19. We accessed information from public databases and publications, and studied the mechanism of infection of SARS-CoV-2 and the interactions of various drugs with SARS-CoV-2 proteins in silico. We found a few antivirals and antiparasitic drugs to show significant interactions with important SARS-CoV-2 proteins. Particularly Galidesivir, Remdesivir, and Pirodavir have been chosen as suggested antiviral drugs; and Proguanil, Mefloquine, and Artesunate have been chosen as suggested antiparasitic drugs based on such predicted interactions. In addition, inhibitors to prevent host-cell entry and a few supportive immune-boosters can be used in different combinations. Our study proposes a four-way attack to this fatal virus for the possible management of COVID-19 armed up with an antiviral, an antiparasitic drug, a cell-entry inhibitor, and a few supportive immune-boosters, which can be used in different combinations in different groups of people. Electronic supplementary material The online version of this article (10.1007/s13337-020-00631-w) contains supplementary material, which is available to authorized users.

Nasopharyngeal Carcinoma (NPC) is one of the leading cancers in India's north-eastern (NE) region affecting a section of the population each year. A proportion of the NPC cases are observed to recur even after therapy, indicating the involvement of other factors. We aimed to explore the NPC and Epstein-Barr virus (EBV) burden in the NE region and investigate the prognostic factors for the NPC patients' poor survival and recurrence. NPC patients' information was obtained from different state hospitals between 2014 and 2019. PCR and Sanger sequencing were performed to detect EBV types. Statistical analysis, including forest plot analysis, Kaplan-Mayer survival plot, Log-rank test, cox hazard regression, and Aalen's additive regression model, were performed to determine prognostic factors for the NPC patients' lower survival and recurrence. We observed an increased incidence of NPC and EBV infection in the past five years. Step-wise statistical analyses pointed out that variable such as non-professionals (B = 1.02, HR = 2.8, 95%CI = 1.5,4.9) workers (B = 0.92, HR = 2.5, 95%CI = 1.4,4.4), kitchen cum bedroom (B = 0.61, HR = 1.8, 95%CI = 1.2,2.8), mosquito repellent (B = 0.60, HR = 1.7, 95%CI = 1.1,2.7), nasal congestion (B = 0.60, HR = 1.8, 95%CI = 1.2,2.8), lower haemoglobin level (B = 0.92, HR = 2.5, 95%CI = 1.3,4.9), tumor stage IV (B = 2.8, HR = 1.8, 95%CI = 1.6,14.3), N2 (B = 1.4, HR = 4.0, 95%CI = 1.8,9.1), N3 (B = 1.9, HR = 6.4, 95%CI = 2.8,15.3), and M+ (B = 2.02, HR = 7.5, 95%CI = 4.1,13.7) revealed significant correlation with NPC patients' poor prognosis (p 0.05). The presence of viral factors also showed a significant association with NPC patients' decreased survival. We concluded that factors related to day-to-day life with EBV infection could be the individual predictor for NPC incidence, lower survival, and disease recurrence.The online version contains supplementary material available at 10.1007/s13337-022-00789-5.

Synthetic and modified natural derivatives are reported as potential bioactive compounds and are being used therapeutically against various diseases in a widespread manner nowadays. Cancerous cells exhibit high levels of reactive oxygen species (ROS) internally, and thus successfully manage to sustain themselves and proliferate via antioxidative mechanisms that maintain a redox balance. On this note, various antioxidants are applied as anticancer compounds, which strategically affects the ongoing oncogenic stress management system in both a pro‑ and antioxidative manner, resulting in cancer restriction, as well as sustaining cell proliferation via antioxidative mechanisms that promote cancer progression. Alike non‑viral cancers, viral cancers exhibit varying levels of ROS during different stages of cancer progression. Hence, successful stress balance should be addressed, depending on the cancer cell stress response during the therapeutic management. The application of antioxidants is crucial and needs to be carefully designed in such cases; the respective underlying mechanisms are less understood. The role of antioxidants controlling the varied levels of stress response at different stages of Kaposi's sarcoma‑associated herpes virus malignancy have not been fully reported. Therefore, the present study aimed to analyze the activity of certain antioxidants in KSHV‑infected oncogenic cells. For this purpose, two naturally derived flavonoid‑based antioxidants (theaflavin and novel curcumin derivatives) were selected and tested in different KSHV‑infected cell lines. The findings presented herein demonstrate that these compounds can successfully induce the death of different KSHV‑positive cells and can restrict the growth of KSHV‑infected cell lines restricting viral reactivation by counteracting the oncogenic stress management system.

Previous studies have demonstrated the interaction between the Epstein-Barr virus (EBV) nuclear antigen 3C (EBNA3C) and the metastatic suppressor Nm23-H1 both in vitro and in vivo (C. Subramanian, M. A. Cotter II, and E. S. Robertson, Nat. Med. 7:350-355, 2001). EBNA3C can reverse the ability of Nm23-H1 to suppress migration of Burkitt's lymphoma and breast carcinoma cell lines in vitro. EBNA3C contributes to EBV-associated human cancers by regulating transcription of a number of cellular and viral promoters and by targeting and altering the transcription activities of the metastasis suppressor Nm23-H1. Cyclo-oxygenase-2 (COX-2), an inducible enzyme important in inflammation, is overexpressed in a variety of cancers and can influence cell migration. In this report we show that Nm23-H1 and EBNA3C can modulate expression of COX-2 in the context of EBV infection and transformation. The levels of COX-2 were consistently higher in EBV-positive cells than in EBV-negative cells. Additionally, we show that Nm23-H1 can upregulate the COX-2 promoter element in luciferase reporter assays, whereas EBNA3C alone did not affect the level of response but clearly contributed to an additive increase when coexpressed with Nm23-H1. The downstream effect of COX-2 expression was also evaluated and showed that prostaglandin E2 levels increased with Nm23-H1 and that there was some level of cooperativity in the presence of EBNA3C. The majority of this response was mediated through the cyclic AMP response element and NF-κB sites. These studies suggest a potential role for COX-2 in EBV-associated human cancers.

Parvovirus B-19, a single human pathogenic member of the Parvoviridae family with it's small ssDNA and non-enveloped structure, is known to cause diseases in erythroid progenitor cells. But a wide range of clinical association of this virus with cells of non-erythroid origins has recently been discovered and many of those are being investigated for such association. Higher substitution rates in due course of evolution has been suggested for this cellular tropism and persistence. In this report, we have summarized the different disease manifestations of B-19 virus and have tried to find out a pattern of pathogenesis. Finally, we have focused on the vaccination strategies available against B-19 virus to correlate these with the mechanisms involved in various diseases caused by this virus.

SARS-CoV-2, or novel coronavirus, is causing the fatal and contagious coronavirus disease-2019 (COVID-19) affecting thousands of people every single day. Researchers are continuously searching for any possible cure and/or vaccine, but no conclusive report is available till date. SARS-CoV-2 is a positive-sense single-stranded RNA virus (+ssRNA virus) which uses its RNA as its genetic material as well as mRNA for the viral protein production. The severity and mode of infection of SARS-CoV-2 are attributed to the presence of a cleavage site for furin endoproteases in the junction of the S1 and S2 domains of the spike glycoprotein. The S1 part attaches the virion to host ACE2 (angiotensin-converting enzyme 2), a cell-surface receptor found in various tissue types including the alveolar epithelial cells, and is internalized inside the endosome. This primes the S2 by cleaving the S1/S2 junction by the cellular serine protease, transmembrane protease serine 2 (TMPRSS2), which actually is a furin endoprotease, and unmasks it for the fusion of the viral and cellular endosome membranes. This fusion facilitates the viral genome to enter into the cytoplasm of the host cell and establish infection. Immediately after entering, the viral RNA uses the host cell’s protein synthesis machinery for producing its own proteins. SARS-CoV-2 does not lyse the host cell; instead, they “bud” off from the cell and infect nearby cells in the same way. As most of the human epithelial cells express ACE2, particularly the alveolar cells and cells of the intestine, those infectious virions eventually spread throughout the body and may pose the host toward a critical condition. The complex signaling required for activating innate and adaptive immunity needs a lot of proteins to be expressed by the host. But in COVID-19, the initial stages of pathogenesis may suppress the immune responses of the host by suppressing the protein production, as stated earlier.

SARS-CoV-2, or novel coronavirus, is causing the fatal and contagious coronavirus disease-2019 (COVID-19) affecting thousands of people every single day. Researchers are continuously searching for any possible cure and/or vaccine, but no conclusive report is available till date. Like many others, we realize that a rapid, immediate, and elaborate strategy must be adopted to protect mankind. To avoid the time-loss due to clinical trials, we have tested some FDA-approved drugs to combat COVID-19. We accessed information from public databases and publications, and studied the mechanism of infection of SARS-CoV-2 and the interactions of various drugs with SARS-CoV-2 proteins in silico. We found a few antivirals and antiparasitic drugs to interact with important SARS-CoV-2 proteins. Particularly Galidesivir, Remdesivir, and Pirodavir are the chosen antiviral drugs; and Proguanil, Mefloquine, and Artesunate are the chosen antiparasitic drugs. In addition, inhibitors to prevent host-cell entry and a few supportive immuneboosters can be used in different combinations. Our study proposes a four-way attack to this fatal virus for the possible management of COVID-19 armed up with an antiviral, an antiparasitic drug, a cell-entry inhibitor, and a few supportive immune-boosters, which can be used in different combinations in different groups of people.

The sudden emergence of SARS-CoV-2 causing the global pandemic is a major public health concern. Though the virus is considered as a novel entity, it is not a completely new member. It is just a new version of previously emerged human SARS corona virus. The rapid evolving nature by changing host body environment and extreme environmental stability, collectively makes SARS-CoV-2 into an extremely virulent genetic variant. The evolution of the virus has been occurred by the continuous process of molecular genetic manipulation, through mutation, deletion and genetic recombinationevents. Different host body environment acts as the supportive system for the pathogen which creates extreme selective pressure. By the process of genetic evolution the pathogen developes new characters. Then the new version of the virus has been naturally selected by susceptible human host and adapt itself inside the host body causing deadly effect. Moreover, extreme environmental stability helps in the process of viral survival outside the host and its transmission. Thus both the host body or internal environment and the external environment performs equally as a source, responsible for shaping the genetic evolution of the SARS-CoV-2 towards theCOVID-19 disease fitness in nature in a pandemic form.

Summary Nasopharyngeal carcinoma (NPC) is a rare malignancy in most parts of the world, but is endemic in some ethnic groups. The association of NPC with the Epstein-Barr virus (EBV) is firmly established; however, the mechanism is still unclear. TLR9 is well known for its essential role in viral pathogen recognition and activation of innate immunity. Here, we report a set of TLR9 polymorphisms in the TIR-2 domain of the TLR9 protein collected from the EBV-infected NPC samples from northeast Indian populations sharing the aforesaid ethnicity. The occurrence of mutations is significantly high in these samples as we found a p value of, Graphical Abstract, Highlights • EBV-associated nasopharyngeal carcinoma (NPC) is endemic in Mongoloids • TLR9 is essential for virus recognition and immunity against cancers • Polymorphisms are common in TLR9 protein in EBV-infected Mongoloids with NPC • NPC susceptibility prediction by TLR9 mutation screening in people for prevention, Biological Sciences; Human Genetics; Cancer

Kaposi’s sarcoma-associated herpesvirus (KSHV) is associated with viral malignancy, related to HIV-AIDS. With a wide geographical discrimination in its occurrence, Asian countries shows low to moderate prevalence with higher occurrence in some particular areas. India is one of the largest countries in Asia, having various geographical and cultural variations where KSHV has been considered as an unthinkable entity to cause any of its associated disease. India has been reported as a low prevalent zone for KSHV malignancy till date. Also there are no reports so far, describing the occurrence pattern of this malignancy. So this review approaches towards figuring out the tendency of prevalence pattern of this malignancy and associated risk factors found to be present in Indian population. From this study it is revealed that, KSHV related malignancy is a relatively newly reported and emerging disease in India and may exist in hidden pockets throughout India in association with tuberculosis. India shows prevalence in HIV-associated Kaposi’s sarcoma in regions where socially discriminated LGBT (lesbian, gay, bisexual, and transgender) groups, unprotected sexual behavior and heterosexuality are the important risk factors for sexually transmitted viral diseases. Anti-retro viral therapy is not sufficient to combat the virus and may act adversely. On a note regarding the clinical representations of Kaposi’s sarcoma, oral, mucosal, pleural and abdominal involvements are observed in worst cases and these can be considered as the main manifesting criteria for this malignancy among Indians. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13337-020-00573-3) contains supplementary material, which is available to authorized users.

Background Interleukin-28B (IL28B) locus on a human chromosomal region mapped to 19q13 execute immune defense against viruses. During Hepatitis C Virus (HCV) infection the IL28B has a promising role in deciding the consequence of infection for spontaneous clearance of viruses or causing chronic liver infection. Treatment of chronic hepatitis C includes use of direct acting antivirals, Pegylated-Interferon (PEG-IFN) and Ribavirin (RBV) therapy. Also, interferon free regimens are suggested to be useful in resistant patients. Numerous reports including Genome-Wide Association Studies (GWAS), comprehensive meta-analysis and independent case-control studies in different population have revealed the association between certain Il-28B polymorphisms and response to the PEGIFN- RBV therapy in patients infected with HCV. Method We searched all peer-reviewed relevant and recent literature manually for the present review. Conclusion The GWAS studies have revealed an important role of IL28B in HCV infection, which was supported by many independent studies and meta-analysis by different groups in different ethnicities. IL28B genotyping may be use as predictors of response for IFN-based therapy and personalized treatment of hepatitis C patient.

Kaposi’s sarcoma associated herpesvirus (KSHV) a gammaherpesvirus establishes perennial latency in the host with periodic reactivation. Occasionally change in the physiological condition like hypoxia, host cell differentiation can trigger the lytic switch and reactivation of the virus. The biologically active form of 1, 25(OH)2 D3 plays a critical role in the regulation of various physiological processes (e.g. regulation of mineral homeostasis and control of bone metabolism). Apart from its role in host physiology, 1, 25(OH)2 D3 has been implicated as a potential agent for the prevention and/or treatment of many a tumors. Here we show that 1, 25(OH)2 D3 induces both death of Kaposi sarcoma associated herpesvirus infected PEL cells and KSHV replication. 1, 25(OH)2 D3 mediated inhibition of proliferation was associated with apoptosis of the PEL cells, and virus reactivation. In addition, p38 signalling is required for KSHV reactivation. Furthermore, treatment of PEL cells with p38 inhibitor abrogated the expression of ORF57, thus blocking lytic switch. Furthermore, silencing of VDR resulted in reduced ORF57 expression compared to the control cells, signifying the potential role of 1, 25(OH)2 D3 in KSHV reactivation. Thus, our studies have revealed a novel role of 1, 25(OH)2 D3 in the regulation of KSHV reactivation and PEL cell death.

Kaposi's sarcoma associated herpes virus (KSHV) infected primary effusion lymphoma (PEL) is a rare aggressive form of non-Hodgkin's lymphoma of B cells. KSHV latent and lytic antigens modulate several host cellular signalling pathways especially mammalian target of rapamycin (mTOR), STAT-3 and nuclear factor-kappa B (NF-κB) for rapid tumor progression and immune evasion. Current chemotherapeutic strategies are becoming ineffective as they kill only dividing cells and inefficient to target molecular pathways crucial for active virus replication and its survival. In this study, we evaluated the efficacy of everolimus, an mTOR inhibitor in inducing apoptosis of PEL cells. Dose-dependent treatment of everolimus triggered mitochondria-mediated caspase-dependent apoptosis in PEL cells. Everolimus downregulated KSHV latent antigen expression with concurrent blocking of lytic reactivation for active virus replication. Everolimus also inhibited latent antigen mediated constitutively active STAT-3 and NF-κB signalling. We co-cultured everolimus treated PEL cells with immature dendritic cells and found activation of dendritic cells with increase in surface expression of CD86 and HLA-DR. As everolimus targets and disrupts KSHV antigens as well as antigen facilitated multiple signalling pathways necessary for KSHV survival and maintenance of infection with synchronised boosting of immune system against viral infection, it can be a better therapeutic approach towards treatment of PEL.

Nasopharyngeal carcinoma (NPC) is a rare variety of head and neck cancers. The risk factors include three major causes: genetic factors, viral infection, and environmental and dietary factors. The types of NPC show strong ethnic and geographic variations. The keratinizing and non-keratinizing types are prevalent in the lower incidence regions like North America and Europe; whereas the undifferentiated type is mostly found in the regions with higher incidences like China, North Africa, Arctic, and Nagaland of North-East India. These suggest a possible major role of the internal genetic factors for generation and promotion of this disease. Viral infections might accelerate the process of carcinogenesis by helping in cellular proliferation and loss of apoptosis. Diet and other environmental factors promote these neoplastic processes and further progression of the disease occurs.

Nasopharyngeal carcinoma (NPC) is one the most confusing and rare malignancy in most part of the world with significantly high occurrence in some populations of Southeast Asia, North Africa and Alaska. Apart from the dietary and environmental factors, NPC is well-associated with Epstein-Barr virus (EBV) infection in these ethnic groups. However, the internal molecular mechanism(s) for such association in specific populations is not known till date. Polymorphisms in the genes of histocompatibility locus antigens (HLA) are reported in NPC, but association of any particular polymorphism with ethnicity is not established yet. Here, we report a set of HLA polymorphisms in EBV-infected NPC samples from Northeast Indian population. These polymorphisms might play an important role for the lack of proper immune function against EBV infection and thus, eventually, for NPC generation in endemic populations like those of Northeast India.

p53, p63, and p73, the members of the p53 family of proteins, are structurally similar proteins that play central roles regulating cell cycle and apoptotic cell death. Alternative splicing at the carboxyl terminus and the utilization of different promoters further categorizes these proteins as having different isoforms for each. Among such isoforms, TA and ΔN versions of each protein serve as the pro and the anti-apoptotic proteins, respectively. Changes in the expression patterns of these isoforms are noted in many human cancers. Proteins of certain human herpesviruses, like Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV), interact with p53 family members and alter their expressions in many malignancies. Upon infections in the B cells and epithelial cells, EBV expresses different lytic or latent proteins during viral replication and latency respectively to preserve viral copy number, chromosomal integrity and viral persistence inside the host. In this review, we have surveyed and summarised the interactions of EBV gene products, known so far, with the p53 family proteins. The interactions between P53 and EBV oncoproteins are observed in stomach cancer, non-Hodgkin's lymphoma (NHL) of the head and neck, Nasopharyngeal Cancer (NPC), Gastric carcinoma (GC) and Burkitt's lymphoma (BL). EBV latent protein EBNA1, EBNA3C, LMP-1, and lytic proteins BZLF-1 can alter p53 expressions in many cancer cell lines. Interactions of p63 with EBNA-1, 2, 5, LMP-2A and BARF-1 have also been investigated in several cancers. Similarly, associations of p73 isoform with EBV latent proteins EBNA3C and LMP-1 have been reported. Methylation and single nucleotide polymorphisms in p53 have also been found to be correlated with EBV infection. Therefore, interactions and altered expression strategies of the isoforms of p53 family proteins in EBV associated cancers propose an important field for further molecular research., Epstein-Bar virus (EBV); p53, p63 and p73 isoforms; Malignancies; Cell biology; Cell death; Cell differentiation; Viruses; Cancer research

The p73 protein has structural and functional homology with the tumor suppressor p53, which plays an important role in cell cycle regulation, apoptosis, and DNA repair. The p73 locus encodes both a tumor suppressor (TAp73) and a putative oncogene (ΔNp73). p73 May play a significant role in p53-deficient lymphomas infected with Epstein–Barr virus (EBV). EBV produces an asymptomatic infection in the majority of the global population, but it is associated with several human B-cell malignancies. The EBV-encoded Epstein–Barr virus nuclear antigen 3C (EBNA3C) is thought to disrupt the cell cycle checkpoint by interacting directly with p53 family proteins. Doxorubicin, a commonly used chemotherapeutic agent, induces apoptosis through p53 and p73 signaling such that the lowΔNp73 level promotes the p73-mediated intrinsic pathway of apoptosis. In this report, we investigated the mechanism by which EBV infection counters p73α-induced apoptosis through EBNA3C.

Cigarette smoking is a crucial factor in the development and progression of multiple cancers including breast. Here, we report that repeated exposure to a fixed, low dose of cigarette smoke condensate (CSC) prepared from Indian cigarettes is capable of transforming normal breast epithelial cells, MCF-10A, and delineate the biochemical basis for cellular transformation. CSC transformed cells (MCF-10A-Tr) were capable of anchorage-independent growth, and their anchorage dependent growth and colony forming ability were higher compared to the non-transformed MCF-10A cells. Increased expression of biomarkers representative of oncogenic transformation (NRP-1, Nectin-4), and anti-apoptotic markers (PI3K, AKT, NFκB) were also noted in the MCF-10A-Tr cells. Short tandem repeat (STR) profiling of MCF-10A and MCF-10A-Tr cells revealed that transformed cells acquired allelic variation during transformation, and had become genetically distinct. MCF-10A-Tr cells formed solid tumors when implanted into the mammary fat pads of Balb/c mice. Data revealed that CSC contained approximately 1.011μg Cd per cigarette equivalent, and Cd (0.0003μg Cd/1×10(7) cells) was also detected in the lysates from MCF-10A cells treated with 25μg/mL CSC. In similar manner to CSC, CdCl2 treatment in MCF-10A cells caused anchorage independent colony growth, higher expression of oncogenic proteins and increased PI3K-AKT-NFκB protein expression. An increase in the expression of PI3K-AKT-NFκB was also noted in the mice xenografts. Interestingly, it was noted that CSC and CdCl2 treatment in MCF-10A cells increased ROS. Collectively, results suggest that heavy metals present in cigarettes of Indian origin may substantially contribute to tumorigenesis by inducing intercellular ROS accumulation and increased expression of PI3K, AKT and NFκB proteins.

Aim: The authors have systematically investigated the anticancer potentiality of silver-based nanoparticles (AgNPs) and the mechanism underlying their biological activity in human colon cancer cells. Materials & methods: Starch-capped AgNPs were synthesized, characterized and their biological activity evaluated through multiple biochemical assays. Results: AgNPs decreased the growth and viability of HCT116 colon cancer cells. AgNP exposure increased apoptosis, as demonstrated by an increase in 4´,6-diamidino-2-phenylindole-stained apoptotic nuclei, BAX/BCL-XL ratio, cleaved poly(ADP-ribose) polymerase, p53, p21 and caspases 3, 8 and 9, and by a decrease in the levels of AKT and NF-κB. The cell population in the G1 phase decreased, and the S-phase population increased after AgNP treatment. AgNPs caused DNA damage and reduced the interaction between p53 and NF-κB. Interestingly, no significant alteration was noted in the levels of p21, BAX/BCL-XL and NF-κB after AgNP treatment in a p53-knockout HCT116 cell line. Conclusion: AgNPs are bona fide anticancer agents that act in a p53-dependent manner. Original submitted 16 March 2012; Revised submitted 25 August 2012; Published online 21 March 2013

Background Breast cancer is considered as an increasing major life-threatening concern among the malignancies encountered globally in females. Traditional therapy is far from satisfactory due to drug resistance and various side effects, thus a search for complementary/alternative medicines from natural sources with lesser side effects is being emphasized. Andrographis paniculata, an oriental, traditional medicinal herb commonly available in Asian countries, has a long history of treating a variety of diseases, such as respiratory infection, fever, bacterial dysentery, diarrhea, inflammation etc. Extracts of this plant showed a wide spectrum of therapeutic effects, such as anti-bacterial, anti-malarial, anti-viral and anti-carcinogenic properties. Andrographolide, a diterpenoid lactone, is the major active component of this plant. This study reports on andrographolide induced apoptosis and its possible mechanism in highly proliferative, invasive breast cancer cells, MDA-MB-231 lacking a functional p53 and estrogen receptor (ER). Furthermore, the pharmacokinetic properties of andrographolide have also been studied in mice following intravenous and oral administration. Results Andrographolide showed a time- and concentration- dependent inhibitory effect on MDA-MB-231 breast cancer cell proliferation, but the treatment did not affect normal breast epithelial cells, MCF-10A (>80 %). The number of cells in S as well as G2/M phase was increased after 36 h of treatment. Elevated reactive oxygen species (ROS) production with concomitant decrease in Mitochondrial Membrane Potential (MMP) and externalization of phosphatidyl serine were observed. Flow cytometry with Annexin V revealed that the population of apoptotic cells increased with prolonged exposure to andrographolide. Activation of caspase-3 and caspase-9 were also noted. Bax and Apaf-1 expression were notably increased with decreased Bcl-2 and Bcl-xL expression in andrographolide-treated cells. Pharmacokinetic study with andrographolide showed the bioavailability of 9.27 ± 1.69 % with a Cmax, of 0.73 ± 0.17 μmol/L and Tmax of 0.42 ± 0.14 h following oral administration. AG showed rapid clearance and moderate terminal half lives (T1/2) of 1.86 ± 0.21 and 3.30 ± 0.35 h following IV and oral administration respectively. Conclusion This investigation indicates that andrographolide might be useful as a possible chemopreventive/chemotherapeutic agent for human breast cancers. Electronic supplementary material The online version of this article (doi:10.1186/s12929-016-0257-0) contains supplementary material, which is available to authorized users.

Andrographolide-induced externalization of phosphatidyl serine and apoptosis in MCF-7 cells. Figure S1. Effect of andrographolide treatment on apoptosis in MCF-7 cells. Cells were treated with IC50 concentration of andrographolide for 48Â h, double stained with annexin V-FITC/PI and analyzed in a FACSVerseâ ˘ (Becton Dickinson, USA) flow cytometer. The percentage Annexin V-positive population refers apoptosis induction (region 2 and 4). Data are representative of three independent experiments. (PDF 88Â kb)

Effect of andrographolide on caspase-9 and caspase-7 activities in MCF-7 cells. Figure S3. Activation of caspase-9 (A) and caspase-7 (B) after treatment with different concentrations (0, 20, 40, 60 and 80 μM) of andrographolide in MCF-7 cells for 24 h. Results shown are representative of three independent experiments. *P

Andrographolide-induced ROS accumulation and MMP loss in MCF-7 cells. Figure S2. (A) Effect of andrographolide treatment on ROS generation in MCF-7 cells. Cells were pretreated with or without 5 mM NAC for 1 h followed by different concentrations (0, 20, 40, 60 and 80 μM) of andrographolide and incubated for the indicated times (24 h and 48 h). Intracellular ROS production was monitored by spectrofluorometer, using 2′, 7′-dichlorofluorescein diacetate (DCF-DA). (B) Loss of MMP (∆ψm) in MCF-7 cells upon treatment with andrographolide (0–80 μM) in presence and absence of NAC. MMP was measured by spectrofluorometer using a fluorescent probe Rhodamine 123. Results shown are representative of three independent experiments. *P

Background: Epstein-Barr virus (EBV) is closely associated with the development of a number of tumors. During latent infection, EBV continuously expresses a number of viral genes which are essential for cell transformation and maintenance of the malignant phenotype of EBV-related tumors. There has been no previous link between EBV and T-cell prolymphocytic leukemia (T-PLL), a distinctive form of leukemia derived from T-cells at an intermediate stage of differentiation between a cortical thymocyte and a mature peripheral blood T-cell. Objective: To determine if EBV was present in the T-PLL cells collected. Study design: T-PLL cells were isolated from the peripheral blood of a patient diagnosed with T-PLL and continuously cultured for about 1 year. The existence of EBV in these cells was detected using multiple strategies including PCR, Western blotting, immunofluorescent assay and flow cytometry analysis. Results: The EBV genome was present in these T-PLL cells by PCR analysis across multiple sites in the viral genome. In addition, these T-PLL cells expressed a number of EBV latent antigens. The EBV oncoproteins LMP1, EBNA1 and EBNA3C were expressed in the majority of the infected cells. Conclusion: This report suggests a potential link between EBV infection and T-PLL and provides new information about the potential contribution of EBV in the initiation or maintenance of T-PLL.

SummaryMembers of the herpesviridae family including Kaposi's sarcoma-associated herpesvirus (KSHV) persist latently in their hosts and harbor their genomes as closed circular episomes. Propagation of the KSHV genome into new daughter cells requires replication of the episome once every cell division and is considered critically dependent on expression of the virus encoded latency-associated nuclear antigen (LANA). This study demonstrates a LANA-independent mechanism of KSHV latent DNA replication. A cis-acting DNA element within a discreet KSHV genomic region termed the long unique region (LUR) can initiate and support replication of plasmids lacking LANA-binding sequences or a eukaryotic replication origin. The human cellular replication machinery proteins ORC2 and MCM3 associated with the LUR element and depletion of cellular ORC2 abolished replication of the plasmids indicating that recruitment of the host cellular replication machinery is important for LUR-dependent replication. Thus, KSHV can initiate replication of its genome independent of any trans-acting viral factors.

Kaposi's sarcoma-associated herpesvirus (KSHV) persists as episomes in infected cells by circularizing at the terminal repeats (TRs). The KSHV episome carries multiple reiterated copies of the terminal repeat, and each copy is capable of supporting replication. Expression of the latency-associated nuclear antigen (LANA) is critical for the replication of TR-containing plasmids. A 32-bp sequence upstream of LANA binding site 1 (LBS1), referred to as RE (replication element), along with LANA binding sites 1 and 2 (RE-LBS1/2), is sufficient to support replication (J. Hu and R. Renne, J. Virol. 79:2637-2642, 2005). In this report we demonstrate that the minimal replicator element (RE-LBS1/2) replicates in synchrony with the host cellular DNA, and only once, in a cell-cycle-dependent manner. Overexpression of the mammalian replication inhibitor geminin blocked replication of the plasmid containing the minimal replicator element, confirming the involvement of the host cellular replication control mechanism, and prevented rereplication of the plasmid in the same cell cycle. Overexpression of Cdt1 also rescued the replicative ability of the RE-LBS1/2-containing plasmids. A chromatin immunoprecipitation assay performed using anti-origin recognition complex 2 (α-ORC2) and α-LANA antibodies from cells transfected with RE-LBS1/2, RE-LBS1, LBS1, or RE showed the association of ORC2 with the RE region. Expression of LANA increased the number of copies of chromatin-bound DNA of replication elements, suggesting that LANA is important for the recruitment of ORCs and may contribute to the stabilization of the replication protein complexes at the RE site.

Kaposi’s sarcoma-associated herpesvirus (KSHV) infects a variety of human cells including cells of epithelial, mesenchymal and endothelial origin. The latency associated nuclear antigen (LANA) of this virus regulates the transcription of a number of viral and cellular genes essential for the survival of the virus in the host cell. TAp63α can induce apoptosis in stressed cells by upregulating various death receptors and loss of mitochondrial membrane potential. The present study demonstrates that LANA inhibits TAp63α-mediated apoptosis by a direct interaction with each other. This interaction also results in a reduction in loss of mitochondrial membrane potential caused by TAp63α. Therefore the present study indicates a possible mechanism of KSHV-infected cells to escape apoptosis and facilitate survival.

K1 is the first open reading frame encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) and lies positionally to the immediate right of the terminal repeats. K1 is a transmembrane glycoprotein having a functional immunoreceptor tyrosine-based activation motif (ITAM) capable of activating B-cell receptor signaling. K1 is expressed mostly during the lytic cycle of the virus and its promoter lies within the terminal repeat which contains the binding sites for latency-associated nuclear antigen (LANA). The K1 promoter (K1p) having LANA binding sites assayed by reporter assay demonstrated that LANA is capable of down-regulating K1 promoter transcriptional activity. However, the KSHV replication transcription activator RTA up-regulates K1p transcriptional activity. The promoter deleted of LANA binding sites showed loss in LANA-mediated down-regulation but was unaffected for RTA-mediated up-regulation. Increasing amounts of RTA rescued LANA-mediated repression of K1p transcriptional activity in cotransfection experiments. Reporter assay data suggest that LANA binding to its cognate sequence is critical for LANA-mediated repression of K1p as a LANA construct lacking the DNA binding domain was unable to repress K1p transcription. Additionally, KSHV primary infection experiments suggest that K1 is expressed during early infection but is repressed on the establishment of latency and so follows an expression profile similar to that of RTA during infection. Analysis of the promoter sequence revealed the presence of Oct-1 transcription factor binding sites within the −116 to +76 region. Mutational analysis of the Oct-1 sites abolished RTA-mediated transcriptional activation, suggesting that RTA up-regulates K1p transcription through binding to this transcription factor.

Background: The true therapeutic benefit of the use of natural products, especially acceptable dietary components such as curcumin, which can spare the normal cells and boost host immunity, has opened new horizons in cancer prevention and treatment. Methods: In our model system we used Ehrlich's ascites carcinoma cells grown in peritoneal carity of Swiss albino mice and curcumin was fed every alternative day. Results: Here, we report that curcumin administration to tumor-bearing mice decreased tumor cell number significantly in a dose-dependent manner. Furthermore, tumor-induced depletion of immune cell number of the host, as was evidenced from the decrease in bone marrow progenitor as well as thymic and splenic mononuclear cell numbers, was reintrated by curcumin. In fact, curcumin inhibited tumor-induced apoptosis of both thymocytes and splenocytes thereby restoring immune cell numbers to normal level in treated Ehrlich's ascites carcinoma-bearing mice. Moreover, curcumin was not toxic to the host; rather in tumor-bearing mice it inhibited hematopoietic toxicity, acted as a hepatoprotective agent and activated depressed anti-oxidant and detoxification systems. Conclusion: The ability of curcumin to regress tumor as well as to protect the host from tumor-induced immunosuppression and toxicity strongly supports the candidacy of curcumin as a potential agent for the dietary therapy of cancer.

Next to water, tea is the most ancient and widely consumed beverage in the world. Epidemiological studies have suggested a cancer protective effect, but the results obtained so far are not conclusive. In the current study, mechanisms of the apoptogenic effect of black tea extract were delineated. Black tea administration to Ehrlich's ascites carcinoma (EAC)-bearing Swiss albino mice caused a significant decrease in the tumor cell count in a dose-dependent manner. Flowcytometric analysis showed an increase in the number of cells in the sub-G(0)/G(1) population signifying tumor cell apoptosis by black tea. These results were further confirmed by nuclear staining that demonstrated distinct morphological features of apoptosis. Our data also revealed an increase in the expression of pro-apoptotic protein p53 in EAC. It is known that upon p53 induction, multiple downstream factors contribute to the decision making between growth arrest and apoptosis. Among those, pro-apoptotic gene Bax is up regulated during p53-mediated apoptosis. On the other hand, p53-mediated growth arrest involves p21 as a major effecter. In our system, increase in p53 expression was followed by moderate expression of p21/Waf-1 and high expression of Bax at protein levels. Interestingly, anti-apoptotic protein Bcl-2 was down regulated resulting in decrease in Bcl-2/Bax ratio. All these observations together signify that black tea-induced apoptogenic signals overrode the growth-arresting message of p21, thereby leading the tumor cells towards death.

The Kaposi's sarcoma-associated herpesvirus infects the human population and maintains latency stage of viral life cycle in a variety of cell types including cells of epithelial, mesenchymal and endothelial origin. The establishment of latent infection by KSHV requires the expression of an unique repertoire of genes among which latency associated nuclear antigen (LANA) plays a critical role in the replication of the viral genome. LANA regulates the transcription of a number of viral and cellular genes essential for the survival of the virus in the host cell. The present study demonstrates the disruption of the host G2/M cell cycle checkpoint regulation as an associated function of LANA. DNA profile of LANA expressing human B-cells demonstrated the ability of this nuclear antigen in relieving the drug (Nocodazole) induced G2/M checkpoint arrest. Caffeine suppressed nocodazole induced G2/M arrest indicating involvement of the ATM/ATR. Notably, we have also shown the direct interaction of LANA with Chk2, the ATM/ATR signalling effector and is responsible for the release of the G2/M cell cycle block.

We have previously reported that 4-(3-(tert-butylamino)imidazo[1,2-α]pyridine-2-yl)benzoic acid, a bicyclic N-fused aminoimidazoles derivative (BNFA-D), possesses anticancer potentiality against breast and kidney cancer cells with minimal toxicities to corresponding normal cells. Here, we explored the mechanism of action of BNFA-D in breast cancer cells using multiple cell-based assays such as MTT, DAPI, FACS, Western blot, and immunoprecipitation. BNFA-D caused apoptosis by upregulating PTEN leading to inhibition of Wnt/TCF signaling cascade and arresting S phase in breast cancer cells. Expression levels of β-catenin, cyclin D1, C-MYC, and phospho-AKT (Ser473) decreased with simultaneous increase in the levels of GSK3β, CK1, and PTEN in BNFA-D-treated MCF-7 cells. Interestingly, silencing of PTEN in breast cancer cells reversed the phenomenon of Wnt/TCF signaling cascade inhibition after BNFA-D treatment.

We previously showed that quinacrine (QC), a small molecule antimalarial agent, also presented anticancer activity in breast cancer cells through activation of p53, p21, and inhibition of topoisomerase activity. Here we have systematically studied the detailed cell death mechanism of this drug using three colon cancer cell lines (HCT-116 parental, isogenic HCT-116 p53-/-, and HCT-116 p21-/- sublines). QC caused a dose-dependent reduction in cell viability in all three cell lines. However, the parental cells were more susceptible to QC-mediated cell death, suggesting that p53- and p21-dependent processes were involved. QC-mediated cell death was measured with the following endpoints: the Bax/Bcl-xL ratio, cleaved PARP, apoptotic nuclei visualized by DAPI staining, and COMET formation. In addition, markers of autophagy were measured. Acridine orange staining revealed increased accumulation of autophagic vacuoles (AVs) after QC treatment in a dose-dependent manner in parental cells, and decreased staining in isogenic HCT-116 p53-/- and HCT-116 p21-/- cells. Immunofluorescence of LC3B was significantly lowered in QC-treated cells lacking p53 or p21, compared to the parental cells. Interestingly, the expression of the autophagy marker LC3B-II after exposure to QC was decreased in either p53 or p21 null cells compared to parental cells. After deletion of p21 in HCT-116 p53-/- cells, no change in LC3B-II expression was noted following QC treatment. Collectively, the results suggest that QC-mediated autophagy and apoptosis dependent on p53 and p21.

We previously reported that quinacrine (QC) has anticancer activity against breast cancer cells. Here, we examine the mechanism of action of QC and its ability to inhibit Wnt-TCF signaling in two independent breast cancer cell lines. QC altered Wnt-TCF signaling components by increasing the levels of adenomatous polyposis coli (APC), DAB2, GSK-3β and axin and decreasing the levels of β-catenin, p-GSK3β (ser 9) and CK1. QC also reduced the activity of the Wnt transcription factor TCF/LEF and its downstream targets cyclin D1 and c-MYC. Using a luciferase-based Wnt-TCF transcription factor assay, it was shown that APC levels were inversely associated with TCF/LEF activity. Induction of apoptosis and DNA damage was observed after treatment with QC, which was associated with increased expression of APC. The effects induced by QC depend on APC because the inhibition of Wnt-TCF signaling by QC is lost in APC-knockdown cells, and consequently, the extent of apoptosis and DNA damage caused by QC is reduced compared with parental cells. Because we previously showed that QC inhibits topoisomerase, we examined the effect of another topoisomerase inhibitor, etoposide, on Wnt signaling. Interestingly, etoposide treatment also reduced TCF/LEF activity, β-catenin and cyclin D1 levels commensurate with induction of DNA damage and apoptosis. Lycopene, a plant-derived antioxidant, synergistically increased QC activity and inhibited Wnt-TCF signaling in cancer cells without affecting the MCF-10A normal breast cell line. Collectively, the data suggest that QC-mediated Wnt-TCF signal inhibition depends on APC and that the addition of lycopene synergistically increases QC anticancer activity.