Methyl CpG binding protein MBD2 has a regulatory role on the BRCA1 gene expression and its modulation by resveratrol in ER+, PR+ & triple-negative breast cancer cells.

BACKGROUND: Resveratrol has demonstrated its ability to regulate BRCA1 gene expression in breast cancer cells, and previous studies have established the binding of MBD proteins to BRCA1 gene promoter regions. However, the molecular mechanism underlying these interactions remains to be elucidated. The aimed to evaluate the impact of MBD proteins on the regulation of BRCA1, BRCA2, and p16 genes and their consequential effects on breast cancer cells. METHODS: Efficacy of resveratrol was assessed using the MTT assay. Binding interactions were investigated through EMSA, ChIP, & MeIP assay. Expression analyses of MBD genes and proteins were conducted using qRT-PCR and western blotting, respectively. Functional assays, including clonogenic, migratory, and sphere formation assays were used to assess cancer cells' colony-forming, metastatic, and tumor-forming abilities. The cytotoxicity of resveratrol on cancer cells was also tested using an apoptosis assay. RESULTS: The study determined an IC50 of 30µM for resveratrol. MBD proteins were found to bind to the BRCA1 gene promoter. Resveratrol exhibited regulatory effects on MBD gene expression, subsequently impacting BRCA1 gene expression and protein levels. Higher concentrations of resveratrol resulted in reduced colony and sphere formation, decreases migration of cancer cells, and an increases number of apoptotic cells in breast cancer cells. Impact Identification of MBD2-BRCA1 axis indicates their significant role in the induction of apoptosis and reduction of metastasis and proliferation in breast cancer cells. Further therapy can be designed to target these MBD proteins and resveratrol could be used along with other anticancer drugs to target breast cancer. CONCLUSIONS: In conclusion MBD2 protein interact to the BRCA1 gene promoter, and resveratrol modulates MBD2 gene expression, which in turn regulates BRCA1 gene expression, and inhibits cell proliferation, migration, and induces apoptosis in ER+, PR+ & Triple negative breast cancer cells.

Long-Term Follow-Up of Abatacept, Post-Transplantation Cyclophosphamide, and Sirolimus-Based Haploidentical Transplantation in Younger Patients with Nonmalignant Diseases.

Haploidentical (haplo) hematopoietic cell transplantation (HCT) for nonmalignant disease (NMD) carries inherent challenges of both alloreactivity and graft failure. Building on promising results from pilot studies in which abatacept was combined with post-transplantation cyclophosphamide (PTCy) and sirolimus (AbaCyS) in younger NMD patients undergoing haplo-HCT, we present the long-term outcomes of this protocol. On the back of uniform disease-specific conditioning regimens containing antithymocyte globulin 4.5 mg/kg from day -9 to day -7, GVHD prophylaxis with AbaCyS consisted of abatacept administered on days 0, +5, +20, +35, and monthly until 180 days with PTCy and sirolimus. The patients were followed up with longitudinal assessment of immune reconstitution, growth, and reproductive development and quality of life (QoL) analyses. Among 40 patients (aplastic anemia, n = 24; hemoglobinopathies, n = 14; and primary immunodeficiencies, n = 2) with a median age of 10 years (range, 2 to 25 years), 95% achieved sustained engraftment. Post-transplantation hemophagocytic syndrome was detected in 3 patients, leading to graft failure in 2 cases. The incidence of acute graft-versus-host disease (GVHD) was 2.6%, and that of chronic GVHD (cGVHD) was 14.3%. Cytomegalovirus, adenovirus, and Epstein-Barr virus infections were observed in 45%, 5%, and 0% respectively. Rates of nonrelapse mortality, overall survival, event-free survival, and GVHD-free, event-free survival were 5%, 95%, 90%, and 82%, respectively, at a median follow-up of 4.6 years. Absence of cGVHD correlated with younger patient age and early sustained recovery of regulatory T cells and mature natural killer cells, which in turn was associated with improved QoL and lack of late infections. The AbaCyS protocol was associated with excellent long-term survival, with attenuation of both early and late alloreactivity in >80% of younger patients undergoing haplo-HCT for NMD. This study sheds light on predispositions to cGVHD and its impact on QoL, warranting further optimization of this approach.

Saliva as a potential non-invasive liquid biopsy for early and easy diagnosis/prognosis of head and neck cancer.

Head and neck squamous cell carcinomas (HNSCCs) are the most devastating diseases in India and southeast Asia. It is a preventable and curable disease if detected early. Tobacco and alcohol consumption are the two major risk-factors but infection of high-risk HPVs are also associated with development of predominantly oral and oropharyngeal carcinomas. Interestingly, unlike cervical cancer, HPV-induced HNSCCs show good prognosis and better survival in contrast, majority of tobacco-associated HPV-ve HNSCCs are highly aggressive with poor clinical outcome. Biomarker analysis in circulatory body-fluids for early cancer diagnosis, prognosis and treatment monitoring are becoming important in clinical practice. Early diagnosis using non-invasive saliva for oral or other diseases plays an important role in successful treatment and better prognosis. Saliva mirrors the body's state of health as it comes into direct contact with oral lesions and needs no trained manpower to collect, making it a suitable bio-fluid of choice for screening. Saliva can be used to detect not only virus, bacteria and other biomarkers but variety of molecular and genetic markers for an early detection, treatment and monitoring cancer and other diseases. The performance of saliva-based diagnostics are reported to be highly (≥95 %) sensitive and specific indicating the test's ability to correctly identify true positive or negative cases. This review focuses on the potentials of saliva in the early detection of not only HPV or other pathogens but also identification of highly reliable gene mutations, oral-microbiomes, metabolites, salivary cytokines, non-coding RNAs and exosomal miRNAs. It also discusses the importance of saliva as a reliable, cost-effective and an easy alternative to invasive procedures.

Arsenicum album Induces Cell Cycle Arrest and Apoptosis, and Inhibits Epithelial-Mesenchymal Transition in Hormone-Dependent MCF7 Breast Cancer Cells.

BACKGROUND: Arsenic trioxide (As2O3) has been in therapeutic use since the 18th century for various types of cancers including skin and breast; however, it gained popularity following FDA approval for its use against acute promyelocytic leukemia. This present work was designed to evaluate the anti-cancer potential of a homeopathic potency of arsenic trioxide (Arsenicum album 6C) in hormone-dependent breast cancer. METHODS: Breast cancer cells (MCF7) were treated with Arsenicum album (Ars 6C) to evaluate its anti-proliferative and apoptotic potential. We examined the effect of Ars 6C on the cell cycle, wound healing, reactive oxygen species (ROS) generation, and modulation of expression of key genes which are aberrant in cancer. RESULTS: Treating breast cancer cells with Ars 6C halted the cell cycle at the sub-G0 and G2/M phases, which could be attributed to DNA damage induced by the generation of ROS. Apoptotic induction was associated with upregulation of Bax expression, with concurrent downregulation of the Bcl-2 gene. Ars 6C was also seen to reverse epithelial to mesenchymal transition and reduce the migration of breast cancer cells. CONCLUSION: The findings suggest that Ars has significant anti-proliferative and apoptotic potential against breast cancer cells. Further studies are required to elucidate the mechanism by which Ars exerts its effect in the in vivo setting.

Computational and In Vitro Approaches to Elucidate the Anti-cancer Effects of Arnica montana in Hormone-Dependent Breast Cancer.

BACKGROUND: Breast cancer is the most common cancer in women worldwide. Use of homeopathic medicines for the treatment of cancers has increased in the last several years. Arnica montana is an anti-inflammatory homeopathic medicine used in traumatic conditions and because of this property we performed investigations for its potential as a chemotherapeutic agent against breast cancer. METHODS: An ethanolic extract of Arnica montana (mother tincture, MT), prepared according to the Homoeopathic Pharmacopoeia of India, was characterized by gas chromatography-mass spectroscopy (GC-MS), followed by computational (in silico) analysis using molecular docking, to identify specific compounds that can bind and modulate the activity of key proteins involved in breast cancer survival and progression. To validate the in silico findings, in a controlled experiment breast cancer cells (MCF7) were treated in vitro with Arnica montana and the cytotoxic effects assessed by flowcytometry, fluorescence microscopy, scratch assay, clonogenic potential and gene expression analysis. RESULTS: Phytochemical characterization of ethanolic extract of Arn MT by GC-MS allowed identification of several compounds. Caryophyllene oxide and 7-hydroxycadalene were selected for molecular docking studies, based on their potential drug-like properties. These compounds displayed selective binding affinity to some of the recognized target proteins of breast cancer, which included estrogen receptor alpha (ERα), progesterone receptor (PR), epidermal growth factor receptor (EGFR), mTOR (mechanistic target of rapamycin) and E-cadherin. In vitro studies revealed induction of apoptosis in MCF7 cells following treatment with Arn MT. Furthermore, treatment with Arn MT revealed its ability to inhibit migration and colony forming abilities of the cancer cells. CONCLUSION: Considering the apoptotic and anti-migratory effects of Arnica montana in breast cancer cells in vitro, there is a need for this medicine to be further validated in an in vivo model.

Urinary concentration of endocrine-disrupting phthalates and breast cancer risk in Indian women: A case-control study with a focus on mutations in phthalate-responsive genes.

BACKGROUND: Phthalates are known endocrine-disrupting chemicals used indiscriminately as constituents in consumer products including food processing, and packaging, cosmetics, personal care and household items. Although, few studies have assessed the risk of breast cancer on exposure to phthalates, their association with breast cancer risk in Indian women have not yet been evaluated. METHODS: We conducted a case-control study involving 171 participants. Urinary concentrations of six phthalate dieters; DMP (Dimethyl phthalate), DEP (Diethyl phthalate), DBP (Dibutyl phthalate), BBP (benzyl butyl phthalate), DEHP (Di-2-ethyl-hexyl phthalate), DINOP (Di-n-octyl phthalate) were estimated by GC-MS and geometric means were calculated. Univariate and multivariable logistic regression was performed to assess breast cancer risk on exposure to phthalates. Genes responsive to phthalates were identified through literature search and matched with NGS data, and gene-enrichment analysis was performed. RESULTS: Significant associations were observed between urinary phthalate concentrations and increased risk of breast cancer for di-butyl phthalate (OR=1.5, 95% CI; 1.06, 2.11, p = 0.002) and di-2-ethyl-hexyl phthalate (>median vs ≤ median; OR=2.97, 95% CI; 1.18, 7.47, p = 0.005) in multivariable analyses. We also found several phthalate-responsive gene mutations in paired breast tumor tissues, which include PTPRD (76.19%), AR (42.86%), CYP1A1 (42.86%), CYP19A1 (23.81%), AHRR (19.05%), PIK3CA (19.05%), CYP1B1 (9.52%), RB1 (9.52%) and MMP9 (9.52%). Gene-enrichment analysis revealed that these genes form a major part of ER/PR, PPAR and HIF-1α-TGF-ß signaling cascades involved in breast cancer CONCLUSION: Although the sample size is small, in this first case-control study from India, DBP and DEHP were found to be associated with increased risk of invasive breast cancer and tumor tissues revealed mutations in several phthalate-responsive genes. It is, therefore suggested that human biomonitoring in India and larger studies evaluating the early life genetic and epigenetic alterations on phthalates exposure are required to establish their role in breast carcinogenesis.

In silico prediction and interaction of resveratrol on methyl-CpG binding proteins by molecular docking and MD simulations study.

Resveratrol enhances the BRCA1 gene expression and the MBD family of proteins bind to the promoter region of the BRCA1 gene. However, the molecular interaction is not yet reported. Here we have analyzed the binding affinity of resveratrol with MBD proteins. Our results suggest that resveratrol binds to the MBD proteins with higher binding affinity toward MeCP2 protein (ΔG = -6.5) by sharing four hydrogen bonds as predicted by molecular docking studies. Further, the molecular dynamics simulations outcomes showed that the backbones of all three protein-ligand complexes are stabilized after the period of 75 ns, constantly fluctuating around the deviations of 0.4 Å, 0.5 Å and 0.7 Å for MBD1, MBD2 and MeCP2, respectively. The inter-molecular hydrogen bonding trajectory analysis for protein-ligand complexes also support the strong binding between MeCP2-resveratrol complex. Further, binding free energy calculations showed binding energy of -94.764 kJ mol-1, -53.826 kJ mol-1 and -36.735 kJ mol-1 for MeCP2-resveratrol, MBD2-resveratrol and MBD1-resveratrol complexes, respectively, which also supported our docking results. Our study also highlighted that the MBD family of proteins forms a binding interaction with other signaling proteins that are involved in various cancer initiation pathways.

Schleichera oleosa Seed Extract Reduced the Proliferation of Breast Cancer by Regulating the BRCA1 and p16 Genes.

BACKGROUND: Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death in females worldwide. Schleichera oleosa (kusum tree) belongs to the Sapindaceae family commonly found in many states of India. This plant is traditionally being used in various pathological conditions. METHODS: In vitro studies were performed using seed extract of Schleichera oleosa. Different concentrations of seed extracts were treated on MCF-7 breast cancer cell line and its effect on migration and colony formation were observed. BRCA1 and p16 gene expression was analyzed by real-time PCR and Western blotting. RESULTS: We have analyzed anticancer and anti-metastatic effects of seed extract in breast cancer and IC50 was 140µg/ml concentration. Further, its inhibitory role in cell migration and colony formation was at 140µg/ml (P<0.0001) concentration and reduced significantly growth of sphere at 140 µg (P<0.0031) and 150µg (P<0.0010) concentration after 5 days of treatment. The apoptosis study was shown a significant increase at 140 µg (P<0.0001) in apoptotic cells. Expression of BRCA1 and p16 were found to be over-expressed as 1.4 and 1.7 fold, respectively, at 140µg/ml concentration after 24 h of treatment at the transcription level. BRCA1 protein was up-regulated but p16 expression down-regulated at 140 to 150µg/ml (One-Way ANOVA, P<0.0001) concentration. CONCLUSION: In this study, we found a significant role of S. Oleosa seed extract has an anti-cancer as well as anti-metastatic via up-regulation of BRCA1 and p16 genes in breast cancer cells.

miRNAs as novel immunoregulators in cancer.

The immune system is a well-known vital regulator of tumor growth, and one of the main hallmarks of cancer is evading the immune system. Immune system deregulation can lead to immune surveillance evasion, sustained cancer growth, proliferation, and metastasis. Tumor-mediated disruption of the immune system is accomplished by different mechanisms that involve extensive crosstalk with the immediate microenvironment, which includes endothelial cells, immune cells, and stromal cells, to create a favorable tumor niche that facilitates the development of cancer. The essential role of non-coding RNAs such as microRNAs (miRNAs) in the mechanism of cancer cell immune evasion has been highlighted in recent studies. miRNAs are small non-coding RNAs that regulate a wide range of post-transcriptional gene expression in a cell. Recent studies have focused on the function that miRNAs play in controlling the expression of target proteins linked to immune modulation. Studies show that miRNAs modulate the immune response in cancers by regulating the expression of different immune-modulatory molecules associated with immune effector cells, such as macrophages, dendritic cells, B-cells, and natural killer cells, as well as those present in tumor cells and the tumor microenvironment. This review explores the relationship between miRNAs, their altered patterns of expression in tumors, immune modulation, and the functional control of a wide range of immune cells, thereby offering detailed insights on the crosstalk of tumor-immune cells and their use as prognostic markers or therapeutic agents.

Long noncoding RNAs: A novel insight in the leukemogenesis and drug resistance in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a common hematological disorder with heterogeneous nature that resulted from blocked myeloid differentiation and an enhanced number of immature myeloid progenitors. During several decades, different factors, including cytogenetic, genetic, and epigenetic have been reported to contribute to the pathogenesis of AML by inhibiting the differentiation and ensuring the proliferation of myeloid blast cells. Recently, long noncoding RNAs (lncRNAs) have been considered as potential diagnostic, therapeutic, and prognostic factors in different human malignancies including AML. Altered expression of lncRNAs is correlated with the transformation of hematopoietic stem and progenitor cells into leukemic blast cells because of their distinct role in the key cellular processes. We discuss the significant role of lncRNAs in the proliferation, survival, differentiation, leukemic stem cells in AML and their involvement in different molecular pathways (insulin-like growth factor type I receptor, FLT3, c-KIT, Wnt, phosphatidylinositol 3-kinase/protein kinase-B, microRNAs), and associated mechanisms such as autophagy, apoptosis, and glucose metabolism. In addition, we aim to highlight the role of lncRNAs as reliable biomarkers for diagnosis, prognosis, and drug resistance for precision medicine in AML.

Non-homologous dsODN increases the mutagenic effects of CRISPR-Cas9 to disrupt oncogene E7 in HPV positive cells.

Genome editing tools targeting high-risk human papillomavirus (HPV) oncogene could be a promising therapeutic strategy for the treatment of HPV-related cervical cancer. We aimed to improve the editing efficiency and detect off-target effects concurrently for the clinical translation strategy by using CRISPR-Cas9 system co-transfected with 34nt non-homologous double-stranded oligodeoxynucleotide (dsODN). We firstly tested this strategy on targeting the Green Fluorescent Protein (GFP) gene, of which the expression is easily observed. Our results showed that the GFP+ cells were significantly decreased when using GFP-sgRNAs with dsODN, compared to using GFP-sgRNAs without donors. By PCR and Sanger sequencing, we verified the dsODN integration into the break sites of the GFP gene. And by amplicon sequencing, we observed that the indels% of the targeted site on the GFP gene was increased by using GFP-sgRNAs with dsODN. Next, we went on to target the HPV18 E7 oncogene by using single E7-sgRNA and multiplexed E7-sgRNAs respectively. Whenever using single sgRNA or multiplexed sgRNAs, the mRNA expression of HPV18 E7 oncogene was significantly decreased when adding E7-sgRNAs with dsODN, compared to E7-sgRNAs without donor. And the indels% of the targeted sites on the HPV18 E7 gene was markedly increased by adding dsODN with E7-sgRNAs. Finally, we performed GUIDE-Seq to verify that the integrated dsODN could serve as the marker to detect off-target effects in using single or multiplexed two sgRNAs. And we detected fewer on-target reads and off-target sites in multiplexes compared to the single sgRNAs when targeting the GFP and the HPV18 E7 genes. Together, CRISPR-Cas9 system co-transfected with 34nt dsODN concurrently improved the editing efficiency and monitored off-target effects, which might provide new insights in the treatment of HPV infections and related cervical cancer.

Insights into the role of complement regulatory proteins in HPV mediated cervical carcinogenesis.

The persistent infection of high-risk Human papillomavirus (HR-HPV) induced cervical cancer remains a challenge in women worldwide including India. Recent advances in cancer research have paved the way for advanced cancer treatment modalities including immunotherapy by manipulating the function or number of cytotoxic T cells. It is well established that anaphylatoxins like C3a and C5a of complement system influence tumor growth by evading apoptosis leading to progression of cancer. The role of the complement system, particularly the complement regulatory proteins (CRPs) which are important determinants of immune response play a crucial role in carcinogenesis. In a tumor microenvironment (TME) assisted suppression of immune effector cells may be achieved through CRPs. However, recent advances in pharmacogenomics including drug designing and combination of these approaches have provided a holistic understanding of signaling pathways and their crosstalk, to regulate cellular communications.This review describes the role of complement system; particularly CRPs in HPV induced cervical carcinogenesis which may be used for designing anti- HPV or cervical cancer therapeutics.

"Smart" drug delivery: A window to future of translational medicine.

Chemotherapy is the mainstay of cancer treatment today. Chemotherapeutic drugs are non-selective and can harm both cancer and healthy cells, causing a variety of adverse effects such as lack of specificity, cytotoxicity, short half-life, poor solubility, multidrug resistance, and acquiring cancer stem-like characteristics. There is a paradigm shift in drug delivery systems (DDS) with the advent of smarter ways of targeted cancer treatment. Smart Drug Delivery Systems (SDDSs) are stimuli responsive and can be modified in chemical structure in response to light, pH, redox, magnetic fields, and enzyme degradation can be future of translational medicine. Therefore, SDDSs have the potential to be used as a viable cancer treatment alternative to traditional chemotherapy. This review focuses mostly on stimuli responsive drug delivery, inorganic nanocarriers (Carbon nanotubes, gold nanoparticles, Meso-porous silica nanoparticles, quantum dots etc.), organic nanocarriers (Dendrimers, liposomes, micelles), antibody-drug conjugates (ADC) and small molecule drug conjugates (SMDC) based SDDSs for targeted cancer therapy and strategies of targeted drug delivery systems in cancer cells.

The comparison of ZFNs, TALENs, and SpCas9 by GUIDE-seq in HPV-targeted gene therapy.

Zinc-finger nucleases (ZFNs), transcription activator-like endonucleases (TALENs), and CRISPR-associated Cas9 endonucleases are three major generations of genome editing tools. However, no parallel comparison about the efficiencies and off-target activity of the three nucleases has been reported, which is critical for the final clinical decision. We for the first time developed the genome-wide unbiased identification of double-stranded breaks enabled by sequencing (GUIDE-seq) method in ZFNs and TALENs with novel bioinformatics algorithms to evaluate the off-targets. By targeting human papillomavirus 16 (HPV16), we compared the performance of ZFNs, TALENs, and SpCas9 in vivo. Our data showed that ZFNs with similar targets could generate distinct massive off-targets (287-1,856), and the specificity could be reversely correlated with the counts of middle "G" in zinc finger proteins (ZFPs). We also compared the TALENs with different N-terminal domains (wild-type [WT]/αN/ßN) and G recognition modules (NN/NH) and found the design (αN or NN) to improve the efficiency of TALEN inevitably increased off-targets. Finally, our results showed that SpCas9 was more efficient and specific than ZFNs and TALENs. Specifically, SpCas9 had fewer off-target counts in URR (SpCas9, n = 0; TALEN, n = 1; ZFN, n = 287), E6 (SpCas9, n = 0; TALEN, n = 7), and E7 (SpCas9, n = 4; TALEN, n = 36). Taken together, we suggest that for HPV gene therapies, SpCas9 is a more efficient and safer genome editing tool. Our off-target data could be used to improve the design of ZFNs and TALENs, and the universal in vivo off-target detection pipeline for three generations of artificial nucleases provided useful tools for genome engineering-based gene therapy.

Urine miRNA signature as a potential non-invasive diagnostic and prognostic biomarker in cervical cancer.

MicroRNAs as cancer biomarkers in serum, plasma, and other body fluids are often used but analysis of miRNA in urine is limited. We investigated the expression of selected miRNAs in the paired urine, serum, cervical scrape, and tumor tissue specimens from the women with cervical precancer and cancer with a view to identify if urine miRNAs could be used as reliable non-invasive biomarkers for an early diagnosis and prognosis of cervical cancer. Expression of three oncomiRs (miR-21, miR-199a, and miR-155-5p) and three tumor suppressors (miR-34a, miR-145, and miR-218) as selected by database search in cervical pre-cancer, cancer, and normal controls including cervical cancer cell lines were analyzed using qRT-PCR. The expression of miRNAs was correlated with various clinicopathological parameters, including HPV infection and survival outcome. We observed a significant overexpression of the oncomiRs and the downregulation of tumor suppressor miRNAs. A combination of miR-145-5p, miR-218-5p, and miR-34a-5p in urine yielded 100% sensitivity and 92.8% specificity in distinguishing precancer and cancer patients from healthy controls and it well correlates with those of serum and tumor tissues. The expression of miR-34a-5p and miR-218-5p were found to be independent prognostic factors for the overall survival of cervical cancer patients. We conclude that the evaluation of the above specific miRNA expression in non-invasive urine samples may serve as a reliable biomarker for early detection and prognosis of cervical cancer.

Specific targeting cancer cells with nanoparticles and drug delivery in cancer therapy.

Nanotechnology has been the latest approach for diagnosis and treatment for cancer, which opens up a new alternative therapeutic drug delivery option to treat disease. Nanoparticles (NPs) display a broad role in cancer diagnosis and has various advantages over the other conventional chemotherapeutic drug delivery. NPs possess more specific and efficient drug delivery to the targeted tissue, cell, or organs and minimize the risk of side effects. NPs undergo passive and active mode of drug targets to tumor area with less elimination of the drug from the system. Size and surface characteristics of nanoparticles play a crucial role in modulating nanocarrier efficiency and the biodistribution of chemo drugs in the body. Several types of nanocarriers, such as polymers, dendrimers, liposome-based, and carbon-based, are studied widely in cancer therapy. Although FDA approved very few nanotechnology drugs for cancer therapy, a large number of studies are undergoing for the development of novel nanocarriers for potent cancer therapy. In this review, we discuss the details of the nano-based therapeutics and diagnostics strategies, and the potential use of nanomedicines in cancer therapy and cancer drug delivery.

HPV+ve/-ve oral-tongue cancer stem cells: A potential target for relapse-free therapy.

The tongue squamous cell carcinoma (TSCC) is a highly prevalent head and neck cancer often associated with tobacco and/or alcohol abuse or high-risk human papillomavirus (HR-HPV) infection. HPV positive TSCCs present a unique mechanism of tumorigenesis as compared to tobacco and alcohol-induced TSCCs and show a better prognosis when treated. The poor prognosis and/or recurrence of TSCC is due to presence of a small subpopulation of tumor-initiating tongue cancer stem cells (TCSCs) that are intrinsically resistant to conventional chemoradio-therapies enabling cancer to relapse. Therefore, targeting TCSCs may provide efficient therapeutic strategy for relapse-free survival of TSCC patients. Indeed, the development of new TCSC targeting therapeutic approaches for the successful elimination of HPV+ve/-ve TCSCs could be achieved either by targeting the self-renewal pathways, epithelial mesenchymal transition, vascular niche, nanoparticles-based therapy, induction of differentiation, chemoradio-sensitization of TCSCs or TCSC-derived exosome-based drug delivery and inhibition of HPV oncogenes or by regulating epigenetic pathways. In this review, we have discussed all these potential approaches and highlighted several important signaling pathways/networks involved in the formation and maintenance of TCSCs, which are targetable as novel therapeutic targets to sensitize/eliminate TCSCs and to improve survival of TSCC patients.

Metabolic regulation in HPV associated head and neck squamous cell carcinoma.

Cancer cells exhibit distinct energy metabolic pathways due to multiple oncogenic events. In normoxia condition, the anaerobic glycolysis (Warburg effect) is highly observed in head and neck squamous cell carcinoma (HNSCC). HNSCC is associated with smoking, chewing tobacco, consumption of alcohol or Human Papillomavirus (HPV) infection primarily HPV16. In recent years, the correlation of HPV with HNSCC has significantly expanded. Despite the recent advancement in therapeutic approaches, the rate of HPV infected HNSCC has significantly increased in the last few years, specifically, in lower middle-income countries. The oncoproteins of High-risk Human Papillomavirus (HR-HPV), E6 and E7, alter the metabolic phenotype in HNSCC, which is distinct from non-HPV associated HNSCC. These oncoproteins, modulate the cell cycle and metabolic signalling through interacting with tumor suppressor proteins, p53 and pRb. Since, metabolic alteration represents a major hallmark for tumorigenesis, HPV acts as a source of biomarker linked to cancer progression in HNSCC. The dependency of cancer cells to specific nutrients and alteration of various metabolic associated genes may provide a unique opportunity for pharmacological intervention in HPV infected HNSCC. In this review, we have discussed the molecular mechanism (s) and metabolic regulation in HNSCC depending on the HPV status. We have also discussed the possible potential therapeutic approaches for HPV associated HNSCC through targeting metabolic pathways.