Health repercussions of environmental exposure to lead: Methylation perspective

Lead (Pb) exposure has been a major public health concern for a long time now due to its permanent adverse effects on the human body. The process of lead toxicity has still not been fully understood, but recent advances in Omics technology have enabled researchers to evaluate lead-mediated alterations at the epigenome-wide level. DNA methylation is one of the widely studied and well-understood epigenetic modifications. Pb has demonstrated its ability to induce not just acute deleterious health consequences but also alters the epi-genome such that the disease manifestation happens much later in life as supported by Barkers Hypothesis of the developmental origin of health and diseases. Furthermore, these alterations are passed on to the next generation. Based on previous in-vivo, in-vitro, and human studies, this review provides an insight into the role of Pb in the development of several human disorders.

Prognostic Value of Melanoma-Associated Antigen-A (MAGE-A) Gene Expression in Various Human Cancers: A Systematic Review and Meta-analysis of 7428 Patients and 44 Studies

Background

Members of the melanoma-associated antigen-A (MAGE-A) subfamily are overexpressed in many cancers and can drive cancer progression, metastasis, and therapeutic recurrence.

Objective

This study is the first comprehensive meta-analysis evaluating the prognostic utility of MAGE-A members in different cancers.

Methods

A systematic literature search was conducted in PubMed, Google Scholar, Science Direct, and Web of Science. The pooled hazard ratios with 95% confidence intervals were estimated to evaluate the prognostic significance of MAGE-A expression in various cancers.

Results

In total, 44 eligible studies consisting of 7428 patients from 11 countries were analysed. Univariate and multivariate analysis for overall survival, progression-free survival, and disease-free survival showed a significant association between high MAGE-A expression and various cancers (P < 0.00001). Additionally, subgroup analysis demonstrated that high MAGE-A expression was significantly associated with poor prognosis for lung, gastrointestinal, breast, and ovarian cancer in both univariate and multivariate analysis for overall survival.

Conclusion

Overexpression of MAGE-A subfamily members is linked to poor prognosis in multiple cancers. Therefore, it could serve as a potential prognostic marker of poor prognosis in cancers.

Electronic supplementary material

The online version of this article (10.1007/s40291-020-00476-5) contains supplementary material, which is available to authorized users.

In silico interaction of HOX cluster-embedded microRNAs and long non-coding RNAs in oral cancer

The essential role HOX-associated non-coding RNAs play in chromatin dynamics and gene regulation has been well documented. The potential roles of these microRNAs and long non-coding RNAs in oral cancer development, with their attendant involvement in various cellular processes including proliferation, invasion, migration, epithelial-mesenchymal transition and metastasis is gaining credence. An interaction network of HOX-embedded non-coding RNAs was constructed to identify the RNA interaction landscape using the arena-Idb platform and visualized using Cytoscape. The miR-10a was shown to interact with HOXA1, miR-10b with HOXD10, miR-196a1 with HOXA5, HOXA7, HOXB8, HOXC8, HOXD8, and miR-196a2 with HOXA5. The lncRNAs, HOTAIR interacted with HOXC11, HOTAIRM1 with HOXA1 and HOXA4, HOTTIP with HOXA13, HOXA-AS2 with HOXA3, HOXA11-AS with HOXA11 and HOXD-AS1 with HOXB8. Changes in the HOX cluster-embedded non-coding RNAs have implications for prognosis and overall disease survival. Our review aims to analyze the functional significance and clinical relevance of non-coding RNAs within the HOX cluster in the context of oral carcinogenesis. Elucidating these interactions between the non-coding RNAs and HOX genes in oral cancer development and progression could pave the way for the identification of reliable biomarkers and potential therapeutic targets.

Advances in Mitochondrial Medicine and Translational Research

Current knowledge of mitochondrial biology and function has provided with tools and technologies that helped a better understanding of the molecular etiology of complex mitochondrial disorders. Dual genetic control of this subcellular organelle function regulates various signaling mechanisms which are essential for metabolism, bioenergetics, fatty acid biosynthesis, and DNA replication & repair. Understanding nuclear mitochondrial crosstalk through advanced genomics as well as clinical perspectives is the overall basis of mitochondrial research and medicine, also the sole objective of Society for Mitochondrial Medicine and Research (SMRM) - India. The eighth virtual international conference on 'Advances in Mitochondrial Medicine and Translational Research' was organized at the Manipal School of Life Sciences, MAHE, Manipal, India, during 6 - 7 November 2020. The aim of the virtual conference was to highlight the recent advances and future perspectives that represent comprehensive clinical and fundamental research interests in the area of mitochondrial biology of human diseases. To systematically present the various findings in mitochondrial biology, the meeting was themed with specific aspects comprising (a) mitochondrial disorders: clinical & genomic perspectives, (b) mitochondria in cancer, (c) mitochondrial metabolism & disorders, and (d) mitochondrial diseases & therapy. This report provides an overview of the recent advancements in the area of mitochondrial biology and medicine that was discussed at the conference.

Conceptualization of functional single nucleotide polymorphisms of polycystic ovarian syndrome genes: an in silico approach

PURPOSE

Polycystic ovarian syndrome (PCOS) is a multi-faceted endocrinopathy frequently observed in reproductive-aged females, causing infertility. Cumulative evidence revealed that genetic and epigenetic variations, along with environmental factors, were linked with PCOS. Deciphering the molecular pathways of PCOS is quite complicated due to the availability of limited molecular information. Hence, to explore the influence of genetic variations in PCOS, we mapped the GWAS genes and performed a computational analysis to identify the SNPs and their impact on the coding and non-coding sequences.

METHODS

The causative genes of PCOS were searched using the GWAS catalog, and pathway analysis was performed using ClueGO. SNPs were extracted using an Ensembl genome browser, and missense variants were shortlisted. Further, the native and mutant forms of the deleterious SNPs were modeled using I-TASSER, Swiss-PdbViewer, and PyMOL. MirSNP, PolymiRTS, miRNASNP3, and SNP2TFBS, SNPInspector databases were used to find SNPs in the miRNA binding site and transcription factor binding site (TFBS), respectively. EnhancerDB and HaploReg were used to characterize enhancer SNPs. Linkage Disequilibrium (LD) analysis was performed using LDlink.

RESULTS

25 PCOS genes showed interaction with 18 pathways. 7 SNPs were predicted to be deleterious using different pathogenicity predictions. 4 SNPs were found in the miRNA target site, TFBS, and enhancer sites and were in LD with reported PCOS GWAS SNPs.

CONCLUSION

Computational analysis of SNPs residing in PCOS genes may provide insight into complex molecular interactions among genes involved in PCOS pathophysiology. It may also aid in determining the causal variants and consequently contributing to predicting disease strategies.

Analysis of Nuclear Encoded Mitochondrial Gene Networks in Cervical Cancer

BACKGROUND

Cervical cancer (CC) is one of the most common female cancers in many developing and underdeveloped countries. High incidence, late presentation, and mortality suggested the need for molecular markers. Mitochondrial defects due to abnormal expression of nuclear-encoded mitochondrial genes (NEMG) have been reported during cancer progression. Nevertheless, the application of NEMG for the prognosis of CC is still elusive. Herein, we aimed to investigate the associations between NEMG and CC prognosis.

MATERIALS AND METHODS

The differentially expressed genes (DEG) in the TCGA-CESC dataset and NEMGs were retrieved from TACCO and Mitocarta2.0 databases, respectively. The impact of methylation on NEMG expression were predicted using DNMIVD and UALCAN tools. HCMDB tool was used to predict genes having metastatic potential. The prognostic models were constructed using DNMIVD, TACCO, GEPIA2, and SurvExpress. The functional enrichment analysis (FEA) was performed using clusterProfiler. The protein-protein interaction network (PPIN) was constructed to identify the hub genes (HG) using String and CytoHubba tools. Independent validation of the HG was performed using Oncomine and Human Protein Atlas databases. The druggable genes were predicted using DGIdb.

RESULTS

Among the 52 differentially expressed NEMG, 15 were regulated by DNA methylation. The expression level of 16, 10, and 7 has the potential for CC staging, prediction of metastasis, and prognosis. Moreover, 1 driver gene and 16 druggable genes were also identified. The FEA identified the enrichment of cancer-related pathways, including AMPK and carbon metabolism in cancer. The combined expression of 10 HG has been shown to affect patient survival.

CONCLUSION

Our findings suggest that the abnormal expression of NEMGs may play a critical role in CC development and progression. The genes identified in our study may serve as a prognostic indicator and therapeutic target in CC.
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A comprehensive review on the carcinogenic potential of bisphenol A: clues and evidence

Bisphenol A [BPA; (CH₃)₂C(C₆H₄OH)₂] is a synthetic chemical used as a precursor material for the manufacturing of plastics and resins. It gained attention due to its high chances of human exposure and predisposing individuals at extremely low doses to diseases, including cancer. It enters the human body via oral, inhaled, and dermal routes as leach-out products. BPA may be anticipated as a probable human carcinogen. Studies using in vitro cell lines, rodent models, and epidemiological analysis have convincingly shown the increasing susceptibility to cancer at doses below the oral reference dose set by the Environmental Protection Agency for BPA. Furthermore, BPA exerts its toxicological effects at the genetic and epigenetic levels, influencing various cell signaling pathways. The present review summarizes the available data on BPA and its potential impact on cancer and its clinical outcome.

Metastatic suppression by DOC2B is mediated by inhibition of epithelial-mesenchymal transition and induction of senescence

Senescence induction and epithelial-mesenchymal transition (EMT) events are the opposite sides of the spectrum of cancer phenotypes. The key molecules involved in these processes may get influenced or altered by genetic and epigenetic changes during tumor progression. Double C2-like domain beta (DOC2B), an intracellular vesicle trafficking protein of the double C2 protein family, plays a critical role in exocytosis, neurotransmitter release, and intracellular vesicle trafficking. DOC2B is repressed by DNA promoter hypermethylation and functions as a tumor growth regulator in cervical cancer. To date, the molecular mechanisms of DOC2B in cervical cancer progression and metastasis is elusive. Herein, the biological functions and molecular mechanisms regulated by DOC2B and its impact on senescence and EMT are described. DOC2B inhibition promotes proliferation, growth, and migration by relieving G0/G1-S arrest, actin remodeling, and anoikis resistance in Cal27 cells. It enhanced tumor growth and liver metastasis in nude mice with the concomitant increase in metastasis-associated CD55 and CD61 expression. Inhibition of EMT and promotion of senescence by DOC2B is a calcium-dependent process and accompanied by calcium-mediated interaction between DOC2B and CDH1. In addition, we have identified several EMT and senescence regulators as targets of DOC2B. We show that DOC2B may act as a metastatic suppressor by inhibiting EMT through induction of senescence via DOC2B-calcium-EMT-senescence axis.

Cervical cytology and associated factors among tribal women of Karnataka, India

BACKGROUND

Reproductive well-being is a crucial element of women's health. Due to the asymptomatic nature of gynaecological morbidities, women rarely seek medical advice in the initial period leading to delayed diagnosis and poor prognosis of subsequent disease. The present study aimed to explore the cervical cytology and its associated risk factors among women from tribal communities of the southern part of coastal Karnataka, India.

METHODS

Papanicolaou (Pap) smear test was performed among 1140 women from three tribal populations, to detect cervical lesions, infections and reactive changes. A semi-structured questionnaire was administered to collect data on socio-demographic and reproductive characteristics of the study population.

RESULTS

The most predominant gynaecological complaint among the participants was severe lower back ache (77.6%), followed by white discharge per vagina (29.0%) and menstrual irregularities (25.9%). Of the 1140 women screened, 12.4% showed cervical microbial infections, 23.6% were reported to have reactive changes, and 0.2% had epithelial cell abnormalities in the cervix. Cervical microbial infections were found to be associated with younger age group, low socio-economic status and younger age at sexual debut.

CONCLUSION

Most of the symptoms suggestive of gynaecological morbidities reported in this study are preventable or treatable. Strengthening ongoing cervical cancer screening programme and implementation of health education programmes among tribal population would be the right policy approach to prevent, detect and treat these symptoms at an early stage and to achieve acceptable health outcomes among tribal women.

Machine-learning-based classification of Stokes-Mueller polarization images for tissue characterization

The microstructural analysis of tissues plays a crucial role in the early detection of abnormal tissue morphology. Polarization microscopy, an optical tool for studying the anisotropic properties of biomolecules, can distinguish normal and malignant tissue features even in the absence of exogenous labelling. To facilitate the quantitative analysis, we developed a polarization-sensitive label-free imaging system based on the Stokes-Mueller calculus. Polarization images of ductal carcinoma tissue samples were obtained using various input polarization states and Stokes-Mueller images were reconstructed using Matlab software. Further, polarization properties, such as degree of linear and circular polarization and anisotropy, were reconstructed from the Stokes images. The Mueller matrix obtained was decomposed using the Lu-Chipman decomposition method to acquire the individual polarization properties of the sample, such as depolarization, diattenuation and retardance. By using the statistical parameters obtained from the polarization images, a support vector machine (SVM) algorithm was trained to facilitate the tissue classification associated with its pathological condition.

Comorbidities and inflammation associated with ovarian cancer and its influence on SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide is a major public health concern. Cancer patients are considered a vulnerable population to SARS-CoV-2 infection and may develop several COVID-19 symptoms. The heightened immunocompromised state, prolonged chronic pro-inflammatory milieu coupled with comorbid conditions are shared in both disease conditions and may influence patient outcome. Although ovarian cancer (OC) and COVID-19 are diseases of entirely different primary organs, both diseases share similar molecular and cellular characteristics in their microenvironment suggesting a potential cooperativity leading to poor outcome. In COVID-19 related cases, hospitalizations and deaths worldwide are lower in women than in males; however, comorbidities associated with OC may increase the COVID-19 risk in women. The women at the age of 50-60 years are at greater risk of developing OC as well as SARS-CoV-2 infection. Increased levels of gonadotropin and androgen, dysregulated renin-angiotensin-aldosterone system (RAAS), hyper-coagulation and chronic inflammation are common conditions observed among OC and severe cases of COVID-19. The upregulation of common inflammatory cytokines and chemokines such as tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-2, IL-6, IL-10, interferon-γ-inducible protein 10 (IP-10), granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein-1 (MCP-1), macrophage colony-stimulating factor (M-CSF), among others in the sera of COVID-19 and OC subjects suggests potentially similar mechanism(s) involved in the hyper-inflammatory condition observed in both disease states. Thus, it is conceivable that the pathogenesis of OC may significantly contribute to the potential infection by SARS-CoV-2. Our understanding of the influence and mechanisms of SARS-CoV-2 infection on OC is at an early stage and in this article, we review the underlying pathogenesis presented by various comorbidities of OC and correlate their influence on SARS-CoV-2 infection.

ZNF471 modulates EMT and functions as methylation regulated tumor suppressor with diagnostic and prognostic significance in cervical cancer

Cervical cancer (CC) is a leading cause of cancer-related death among women in developing countries. However, the underlying mechanisms and molecular targets for therapy remain to be fully understood. We investigated the epigenetic regulation, biological functions, and clinical utility of zinc-finger protein 471 (ZNF471) in CC. Analysis of cervical tissues and five independent public datasets of CC showed significant hypermethylation of the ZNF471 gene promoter. In CC cell lines, promoter DNA methylation was inversely correlated with ZNF471 expression. The sensitivity and specificity of the ZNF471 hypermethylation for squamous intraepithelial lesion (SIL) vs tumor and normal vs tumor was above 85% with AUC of 0.937. High methylation and low ZNF471 expression predicted poor overall and recurrence-free survival. We identified -686 to +114 bp as ZNF471 promoter, regulated by methylation using transient transfection and luciferase assays. The promoter CpG site methylation of ZNF471 was significantly different among cancer types and tumor grades. Gal4-based heterologous luciferase reporter gene assays revealed that ZNF471 acts as a transcriptional repressor. The retroviral mediated overexpression of ZNF471 in SiHa and CaSki cells inhibited growth, proliferation, cell migration, invasion; delayed cell cycle progression in vitro by increasing cell doubling time; and reduced tumor growth in vivo in nude mice. ZNF471 overexpression inhibited key members of epithelial-mesenchymal transition (EMT), Wnt, and PI3K-AKT signaling pathways. ZNF471 inhibited EMT by directly targeting vimentin as analyzed by bioinformatic analysis, ChIP-PCR, and western blotting. Thus, ZNF471 CpG specific promoter methylation may determine the prognosis of CC and could function as a potential tumor suppressor by targeting EMT signaling.

Integrated bioinformatic analysis of miR-15a/16-1 cluster network in cervical cancer

The miR-15a/16-1 cluster is abnormally expressed in cervical cancer (CC) tissues and plays a vital role in cervical carcinogenesis. We aimed to evaluate the miR-15a/16-1 expression in healthy and cancerous cervical tissues, identify the associated networks, and to test its prognostic significance. miR-15a/16-1-MC expressions were analyzed in TCGA-CESC datasets by UALCAN, GEPIA2, and Datasetviewer. miR-15a/16-1 validated targets were extracted from mirTarBase and in silico functional analysis of the target genes were performed using WebGestalt. The interaction networks were constructed by the miRNet, STRING, and NetworkAnalyst tools. The prognostic significance and metastatic potential of the target genes were predicted using UALCAN and HCMDB. The FDA approved drugs to target miR-15a/16-1 and target gene network in CC were performed using DGIdb, STITCH and PanDrugs. TCGA-CESC and GEO data analysis suggested significant overexpression of miR-15a/16-1 in CC samples. The Kaplan-Meier survival analysis showed that miR-15a and its four target genes (BCL2, CCNE1, NUP50, and RBPJ) influence the overall survival of CC patients. Among the 66 differentially expressed target genes, 12 of them are linked to head, neck, or lung metastasis. Functional enrichment analysis predicted the association of this cluster with p53 signaling, human papillomavirus infection, PI3-AKT signaling pathway, and pathways in cancer. Drug-gene interaction analysis showed 52 potential FDA approved drugs to interact with the miR-15a/16-1 target genes. Nine of the 52 drugs are currently used as a chemotherapeutic agent for the treatment of CC patients. The present study shows that miR-15a/16-1 expression can be used as a clinical marker and target for therapy in CC.

Contribution of nuclear and mitochondrial gene mutations in mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome

Background

Mitochondrial disorders are clinically complex and have highly variable phenotypes among all inherited disorders. Mutations in mitochon drial DNA (mtDNA) and nuclear genome or both have been reported in mitochondrial diseases suggesting common pathophysiological pathways. Considering the clinical heterogeneity of mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) phenotype including focal neurological deficits, it is important to look beyond mitochondrial gene mutation.

Methods

The clinical, histopathological, biochemical analysis for OXPHOS enzyme activity, and electron microscopic, and neuroimaging analysis was performed to diagnose 11 patients with MELAS syndrome with a multisystem presentation. In addition, whole exome sequencing (WES) and whole mitochondrial genome sequencing were performed to identify nuclear and mitochondrial mutations.

Results

Analysis of whole mtDNA sequence identified classical pathogenic mutation m.3243A > G in seven out of 11 patients. Exome sequencing identified pathogenic mutation in several nuclear genes associated with mitochondrial encephalopathy, sensorineural hearing loss, diabetes, epilepsy, seizure and cardiomyopathy (POLG, DGUOK, SUCLG2, TRNT1, LOXHD1, KCNQ1, KCNQ2, NEUROD1, MYH7) that may contribute to classical mitochondrial disease phenotype alone or in combination with m.3243A > G mutation.

Conclusion

Individuals with MELAS exhibit clinical phenotypes with varying degree of severity affecting multiple systems including auditory, visual, cardiovascular, endocrine, and nervous system. This is the first report to show that nuclear genetic factors influence the clinical outcomes/manifestations of MELAS subjects alone or in combination with m.3243A > G mutation.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10390-9) contains supplementary material, which is available to authorized users.

In silico analysis of HOX-associated transcription factors as potential regulators of oral cancer

OBJECTIVE

The objective of this study was identification of the transcription factor binding sites (TFBS) in the promoter of HOX genes and elucidation of the comprehensive interaction of transcription factors (TFs)/genes with HOX.

METHODOLOGY

Promoter sequences of HOXA3, HOXA5, HOXA9, HOXA10, HOXA13, HOXB5, HOXC10, HOXC12, and HOXD10 were analyzed to predict the TFBS and their targets using TRANSFAC, TRRUST, and Harmonizome. Functional analysis of the processed data sets was carried out using DAVID and GATHER gene annotation tools. A network of regulatory interactions was constructed using NetworkAnalyst and a comprehensive illustration of the TF-gene network was constructed with HOX as a central hub using the Encyclopedia of DNA Elements chromatin immunoprecipitation sequencing data. Further, the enriched network was constructed to elucidate the roles of these genes in the various pathways.

RESULTS

Binding sites for E2F1, HNF3α, SP3, and KLF6 were common to promoter regions of all of the HOX genes. The functional annotation and pathway analysis elucidated the regulatory activity of a distinct set of TF-genes in interaction with HOX. A P value ≤.05 and false discovery rate ≤0.01 were considered statistically significant.

CONCLUSION

We have confirmed that the predicted TFBSs in the HOX gene promoters function in transcriptional regulation by modulating target gene activity. TF-gene interactions are crucial to understanding oral carcinogenesis.

Small nucleolar RNA and its potential role in breast cancer - A comprehensive review

Small Nucleolar RNAs (snoRNAs) are known for their canonical functions, including ribosome biogenesis and RNA modification. snoRNAs act as endogenous sponges that regulate miRNA expression. Thus, precise snoRNA expression is critical for fine-tuning miRNA expression. snoRNAs processed into miRNA-like sequences play a crucial role in regulating the expression of protein-coding genes similar to that of miRNAs. Recent studies have linked snoRNA deregulation to breast cancer (BC). Inappropriate snoRNA expression contributes to BC pathology by facilitating breast cells to acquire cancer hallmarks. Since snoRNAs show significant differential expression in normal and cancer conditions, measuring snoRNA levels could be useful for BC prognosis and diagnosis. The present article provides a comprehensive overview of the role of snoRNAs in breast cancer pathology. More specifically, we have discussed the regulation, biological function, signaling pathways, and clinical utility of abnormally expressed snoRNAs in BC. Besides, we have also discussed the role of snoRNA host genes in breast tumorigenesis and emerging and future research directions in the field of snoRNA and cancer.

The Role of Calcium Signaling in Regulation of Epithelial-Mesenchymal Transition

Despite substantial advances in the field of cancer therapeutics, metastasis is a significant challenge for a favorable clinical outcome. Epithelial to mesenchymal transition (EMT) is a process of acquiring increased motility, invasiveness, and therapeutic resistance by cancer cells for their sustained growth and survival. A plethora of intrinsic mechanisms and extrinsic microenvironmental factors drive the process of cancer metastasis. Calcium (Ca2+) signaling plays a critical role in dictating the adaptive metastatic cell behavior comprising of cell migration, invasion, angiogenesis, and intravasation. By modulating EMT, Ca2+ signaling can regulate the complexity and dynamics of events leading to metastasis. This review summarizes the role of Ca2+ signal remodeling in the regulation of EMT and metastasis in cancer.

Influence of VDR and HFE polymorphisms on blood lead levels of occupationally exposed workers

Lead is a ubiquitous heavy metal toxin of significant public health concern. Every individual varies in their response to lead's toxic effects due to underlying genetic variations in lead metabolizing enzymes or proteins distributed in the population. Earlier studies, including our lab, have attributed the influence of ALAD (δ-Aminolevulinate dehydratase) polymorphism on blood lead retention and ALAD activity. The present study aimed to investigate the influence of VDR (Vitamin D receptor) and HFE (Hemochromatosis) polymorphisms in modulating blood lead levels (BLLs) of occupationally exposed workers. 164 lead-exposed subjects involved in lead alloy manufacturing and battery breaking and recycling processes and 160 unexposed controls with BLLs below 10 µg/dL recruited in the study. Blood lead levels, along with a battery of biochemical assays and genotyping, were performed. Regression analysis revealed a negative influence of BLLs on ALAD activity (p < 0.0001) and a positive influence on smokeless tobacco use (p < 0.001) in lead-exposed subjects. A predicted haplotype of the three VDR polymorphisms computed from genotyping data revealed that T-A-A haplotype increased the BLLs by 0.93 units (p ≤ 0.05) and C-C-A haplotype decreased the BLLs by 7.25 units (p ≤ 0.05). Further analysis revealed that the wild-type CC genotype of HFE H63D presented a higher median BLL, indicating that variant C allele may have a role in increasing the concentration of lead. Hence, the polymorphism of genes associated with lead metabolism might aid in predicting genetic predisposition to lead and its associated effects.

Molecular landscape of recurrent cervical cancer

Cervical cancer (CC) is a major gynecological problem in developing and underdeveloped countries. Despite the significant advancement in early detection and treatment modalities, several patients recur. Moreover, the molecular mechanisms responsible for CC recurrence remains obscure. The patients with CC recurrence often show poor prognosis and significantly high mortality rates. The clinical management of recurrent CC depends on treatment history, site, and extent of the recurrence. Owing to poor prognosis and limited treatment options, recurrent CC often presents a challenge to the clinicians. Several in vitro, in vivo, and patient studies have led to the identification of the critical molecular changes responsible for CC recurrence. Both aberrant genetic and epigenetic modifications leading to altered cell signaling pathways have been reported to impact CC recurrence. Researchers are currently trying to dissect the molecular pathways in CC and translate these findings for better management of disease. This article attempts to review the existing knowledge of disease relapse, accompanying challenges, and associated molecular players in CC.

Lead exposure induces metabolic reprogramming in rat models

Lead is a toxin of great public health concern affecting the young and aging population. Several factors such as age, gender, lifestyle, dose, and genetic makeup result in interindividual variations to lead toxicity mainly due to variations in metabolic consequences. Hence, the present study aimed to examine dose-dependent lead-induced systemic changes in metabolism using rat model by administering specific doses of lead such as 10 (low lead; L-Pb), 50 (moderate lead; M-Pb), and 100 mg/kg (high lead; H-Pb) body weight for a period of one month. Biochemical and haematological analysis revealed that H-Pb was associated with low body weight and feed efficiency, low total protein levels (p ≤ 0.05), high blood lead (Pb-B) levels (p ≤ 0.001), low ALAD (δ-aminolevulinate dehydratase) activity (p ≤ 0.0001), high creatinine (p ≤ 0.0001) and blood urea nitrogen (BUN) (p ≤ 0.01) levels, elevated RBC and WBC counts, reduced haemoglobin and blood cell indices compared to control. Spatial learning and memory test revealed that H-Pb exposed animals presented high latency to the target quadrant and escape platform compared to other groups indicating H-Pb alters cognition function in rats. Histopathological changes were observed in liver and kidney as they are the main target organs of lead toxicity. LC-MS analysis further revealed that Butyryl-L-carnitine (p ≤ 0.01) and Ganglioside GD2 (d18:0/20:0) (p ≤ 0.05) levels were significantly reduced in H-Pb group compared to all groups. Further, pathway enrichment analysis revealed abundance and significantly modulated metabolites associated with oxidative stress pathways. The present study is the first in vivo model of dose-dependent lead exposure for serum metabolite profiling.

Signaling pathways promoting epithelial mesenchymal transition in oral submucous fibrosis and oral squamous cell carcinoma

Epithelial-mesenchymal transition (EMT) is a critical process that occurs during the embryonic development, wound healing, organ fibrosis and the onset of malignancy. Emerging evidence suggests that the EMT is involved in the invasion and metastasis of cancers. The inflammatory reaction antecedent to fibrosis in the onset of oral submucous fibrosis (OSF) and the role of EMT in its malignant transformation indicates a hitherto unexplored involvement of EMT. This review focuses on the role of EMT markers which are regulators of the EMT mediated complex network of molecular mechanisms involved in the pathogenesis of OSF and OSCC. Further the gene enrichment analysis and pathway analysis supports the association of the upregulated and downregulated genes in various EMT regulating pathways.

The emerging role of miRNA clusters in breast cancer progression

Micro RNAs (miRNAs) are small non-coding RNAs that are essential for regulation of gene expression of the target genes. Large number of miRNAs are organized into defined units known as miRNA clusters (MCs). The MCs consist of two or more than two miRNA encoding genes driven by a single promoter, transcribed together in the same orientation, that are not separated from each other by a transcription unit. Aberrant miRNA clusters expression is reported in breast cancer (BC), exhibiting both pro-tumorogenic and anti-tumorigenic role. Altered MCs expression facilitates to breast carcinogenesis by promoting the breast cells to acquire the various hallmarks of the cancer. Since miRNA clusters contain multiple miRNA encoding genes, targeting cluster may be more attractive than targeting individual miRNAs. Besides targeting dysregulated miRNA clusters in BC, studies have focused on the mechanism of action, and its contribution to the progression of the BC. The present review provides a comprehensive overview of dysregulated miRNA clusters and its role in the acquisition of cancer hallmarks in BC. More specifically, we have presented the regulation, differential expression, classification, targets, mechanism of action, and signaling pathways of miRNA clusters in BC. Additionally, we have also discussed the potential utility of the miRNA cluster as a diagnostic and prognostic indicator in BC.