Role In Malignant Transformation Research Articles

Computational methods reveal novel functionalities of PIWI-interacting RNAs in human papillomavirus-induced head and neck squamous cell carcinoma.

Human papillomavirus (HPV) infection is the fastest growing cause of head and neck squamous cell carcinoma (HNSCC) today, but its role in malignant transformation remains unclear. This study aimed to conduct a comprehensive investigation of PIWI-interacting RNA (piRNA) alterations and functionalities in HPV-induced HNSCC. Using 77 RNA-sequencing datasets from TCGA, we examined differential expression of piRNAs between HPV16(+) HNSCC and HPV(–) Normal samples, identifying a panel of 30 HPV-dysregulated piRNAs. We then computationally investigated the potential mechanistic significances of these transcripts in HPV-induced HNSCC, identifying our panel of piRNAs to associate with the protein PIWIL4 as well as the RTL family of retrotransposon-like genes, possibly through direct binding interactions. We also recognized several HPV-dysregulated transcripts for their correlations with well-documented mutations and copy number variations in HNSCC as well as HNSCC clinical variables, demonstrating the potential ability of our piRNAs to play important roles in large-scale modulation of HNSCC in addition to their direct, smaller-scale interactions in this malignancy. The differential expression of key piRNAs, including NONHSAT077364, NONHSAT102574, and NONHSAT128479, was verified in vitro by evaluating endogenous expression in HPV(+) cancer vs. HPV(–) normal cell lines. Overall, our novel study provides a rigorous investigation of piRNA dysregulation in HPV-related HNSCC, and lends critical insight into the idea that these small regulatory transcripts may play crucial and previously unidentified roles in tumor pathogenesis and progression.

Matrine inhibits BCR/ABL mediated ERK/MAPK pathway in human leukemia cells.

The BCR/ABL fusion gene and its downstream signaling pathways such as Ras/Raf/MAPK, JAK/STAT3, and PI3K/AKT pathways play important roles in malignant transformation of leukemia, especially chronic myelogenous leukemia (CML). Our previous study showed that matrine, an alkaloid extracted from a Chinese herb radix sophorae, significantly inhibited the proliferation of human CML K562cells, induced cell cycle arrest in G0/G1, and promoted cell apoptosis. In the present study, we investigated the molecular mechanism of matrine in the growth inhibition of leukemia cells using K562 and HL-60 cell lines. RT-PCR and Western blot assay demonstrated that the expression of BCR/ABL in K562 and HL-60 cells was significantly inhibited by matrine treatment. Phosphorylation of MEK1, ERK1/2, and their upstream adaptor molecules Shc and SHP2 were significantly downregulated. The protein and mRNA expression of components of the ERK/MAPK signal pathway, and Bcl-xL, Cyclin D1, and c-Myc, were dramatically reduced. Conversely, the expression of p27, a negative regulator of cell cycle progression, increased after matrine treatment. These results indicated that the inhibition of ERK/MAPK and BCR/ABL signaling pathway was associated with matrine’s suppressive effects on the growth of K562 and HL-60 cells. In in vivo study, matrine significantly decreased the mortality rate of tumor-baring mice and suggested that matrine could exert its anti-leukemia effect in vivo.

Esophageal Squamous Papilloma: A Case Series

Introduction Esophageal squamous papilloma (ESP) is a rare neoplasm, usually appearing as an incidental finding in 0.01-0.45% of EGDs. The prevalence has increased over the last 10-15 years. ESP arises from a chronic inflammatory reaction related to GERD, smoking, alcohol, food impaction, caustic or mechanical injury, or HPV infection. They are reportedly more common in middle-aged men. We present 2 cases found in women. Case 1 A 61 year old female with no significant medical or surgical history presented with a 6 month history of progressive dysphagia to solids and liquids. She had occasional vomiting and epigastric pain after eating. Review of systems was otherwise negative. The patient was a nonsmoker, without significant alcohol use. Her medications included a multivitamin and lansoprazole. Physical exam was unremarkable. She had a normal barium swallow study. An EGD revealed esophagitis and a single 2 mm polyp in the proximal third of the esophagus. Pathology showed ESP. Case 2 A 19 year old female with history of lupus, Sjogren's syndrome and GERD presented with intermittent dark hematemesis over the past 1 month. She denied abdominal pain, hematochezia or melena. Her medications included mycophenolate, hydroxychloroquine, prednisone, ranitidine, and celecoxib. She had no significant past surgical or family history. Vital signs and physical exam were unremarkable except for heme-positive stool on rectal exam. Labs were notable for severe anemia with hematocrit of 14.9%. An EGD revealed esophageal ulcers and multiple polypoid masses in the distal esophagus, the largest of which was biopsied and found to be squamous papilloma. HPV testing was negative. Discussion ESPs are typically asymptomatic, but can present with an array of clinical manifestations as demonstrated by the cases above. The ESP in case 1 was an incidental finding. Due to its small size, it is unlikely to have contributed to the patient's dysphagia. Conversely, in case 2, the ESP likely developed in response to corrosive reflux. The polypoid area was friable, and likely caused her anemia. Although ESP is benign, there is controversy about its malignant potential. HPV is present in 5-50% of ESPs, and may play a role in malignant transformation of ESP. Because data is lacking on ESP as a premalignant lesion, endoscopic removal is recommended. Long-term follow up of ESP is needed to better understand their potential for progression to malignancy and surveillance after removal.Figure: The 2 mm ESP described in Case 1 is shown in endoscopic view (panel A) and on H&E staining, demonstrating the branched appearance of the papillae underlying the esophageal mucosa (panel B).Figure: This is an endoscopic image from Case 2 depicting an ulcerated multi-polypoid mass which was histologically identified to be a squamous papilloma. The yellow arrows indicate site of biopsy.

DNA methylation and histone modifications as epigenetic regulation in prostate cancer (Review).

Prostate cancer is the second most commonly diagnosed cancer in men in Poland after lung cancer and the third leading cause of cancer-related mortality after lung and colon cancer. The etiology of most cases of prostate cancer are not fully known, and therefore it is essential to search for the molecular basis of prostate cancer and markers for the early diagnosis of this type of cancer. Epigenetics deals with changes in gene expression that are not determined by changes in the DNA sequence. Epigenetic changes refer to changes in the structure of DNA, which are the result of DNA modification after replication and/or post-translational modification of proteins associated with DNA. In contrast to mutations, epigenetic changes are reversible and occur very rapidly. The major epigenetic mechanisms include DNA methylation, modification of histone proteins, chemical modification and chromatin remodeling changes in gene expression caused by microRNAs (miRNAs). Epigenetic changes play an important role in malignant transformation and can be specific to types of cancers including prostate cancer.

Lysine-specific demethylase 1 (LSD1) destabilizes p62 and inhibits autophagy in gynecologic malignancies

Lysine-specific demethylase 1 (LSD1) – also known as KDM1A – is the first identified histone demethylase. LSD1 is highly expressed in numerous human malignancies and has recently emerged as a target for anticancer drugs. Owing to the presence of several functional domains, we speculated that LSD1 could have additional functions other than histone demethylation. P62 – also termed sequestasome 1 (SQSTM1) – plays a key role in malignant transformation, apoptosis, and autophagy. Here, we show that a high LSD1 expression promotes tumorigenesis in gynecologic malignancies. Notably, LSD1 inhibition with either siRNA or pharmacological agents activates autophagy. Mechanistically, LSD1 decreases p62 protein stability in a demethylation-independent manner. Inhibition of LSD1 reduces both tumor growth and p62 protein degradation in vivo. The combination of LSD1 inhibition and p62 knockdown exerts additive anticancer effects. We conclude that LSD1 destabilizes p62 and inhibits autophagy in gynecologic cancers. LSD1 inhibition reduces malignant cell growth and activates autophagy. The combinations of LSD1 inhibition and autophagy blockade display additive inhibitory effect on cancer cell viability. A better understanding of the role played by p62 will shed more light on the anticancer effects of LSD1 inhibitors.

Modulation of Dkk-3 and claudin-5 as new therapeutic strategy in the treatment of meningiomas

Meningiomas are the most common tumors of the central nervous system, where the incidence is around 25% of all primary brain tumors. The optimal treatment is represented by total resection accompanied by the removal of the dura mater and bone when infiltrated by the tumor. The histological grading is the most important prognostic factor in the outcome. However, recurrences do occur in a significant proportion (10–25%) of cases, representing the most relevant clinical complication. Molecular therapies are providing to give different opportunities in the development of new treatments. The Dickkopf-related family of proteins includes four secretory proteins. The expression of the REIC/Dkk-3 gene is down-regulated in many tumor cell lines and could contribute to the immunomodulatory properties of the tissue microenvironment. An important role in carcinogenesis is played by Dickkopf protein-related protein 3, which is involved in embryonic development through its interaction and modulation of the pathway of the Wnt signal transduction. The mutations of this pathway are of clinical importance, because they lead to the onset of several cancers, including brain tumors, being also involved in tumor angiogenesis. The claudin-5, is an integral membrane protein, which regulate the permeability of the blood-brain barrier. In various pathological processes, including inflammation, trauma and tumor, claudin 5 regulate the change in endothelial or epithelial permeability, therefore, modification in claudin-5 expression may play a role in malignant transformation. The aim of our study is to demonstrate the role of Dkk-3 and claudin-5 in the pathogenesis of meningiomas. A more correct identification of the role of these proteins might suggest interesting and new molecular targets for future therapeutic protocols.

The oligodendrocyte lineage transcription factor 2 (OLIG2) is epigenetically regulated in acute myeloid leukemia

DNA methylation differences between normal tissue and cancerous tissue resulting in differential expression of genes are a hallmark of acute myeloid leukemia (AML) and can provide malignant cells with a growth advantage via silencing of specific genes, for example, transcription factors. Oligodendrocyte lineage transcription factor 2 (OLIG2) was reported to be differentially methylated and associated with prognosis in AML and, as reported for acute lymphoblastic leukemia and malignant glioma, may play a role in malignant transformation. We report that DNA methylation of OLIG2 is associated with decreased expression of mRNA in AML cell lines and patients. Moreover, in cell lines, decreased mRNA expression also translated into decreased OLIG2 protein expression. Treatment of non-expressing cell lines PL-21 and U-937 with the demethylating agent decitabine resulted in robust re-expression of OLIG2 on mRNA and protein levels. Furthermore, stable overexpression of OLIG2 in non-expressing cell lines Kasumi-1 and U-937, using a lentiviral vector system, led to moderate growth inhibition after 4 days and resulted in signs of differentiation in U-937 cells. Interestingly, although CD34 + cells from healthy donors and 10 of 12 AML patients exhibited no protein expression, OLIG2 was expressed in two patients, both bearing the translocation t(15;17), corresponding to OLIG2 expression in NB-4 cells, also harboring t(15;17). In conclusion, we provide first evidence that OLIG2 is epigenetically regulated via DNA methylation and expressed in a subset of AML patients. OLIG2 may exert antiproliferative activity in leukemia cell lines, and its potential leukemia-suppressing role in AML warrants further investigation.

An essential EBV latent antigen 3C binds Bcl6 for targeted degradation and cell proliferation.

The latent EBV nuclear antigen 3C (EBNA3C) is required for transformation of primary human B lymphocytes. Most mature B-cell malignancies originate from malignant transformation of germinal center (GC) B-cells. The GC reaction appears to have a role in malignant transformation, in which a major player of the GC reaction is Bcl6, a key regulator of this process. We now demonstrate that EBNA3C contributes to B-cell transformation by targeted degradation of Bcl6. We show that EBNA3C can physically associate with Bcl6. Notably, EBNA3C expression leads to reduced Bcl6 protein levels in a ubiquitin-proteasome dependent manner. Further, EBNA3C inhibits the transcriptional activity of the Bcl6 promoter through interaction with the cellular protein IRF4. Bcl6 degradation induced by EBNA3C rescued the functions of the Bcl6-targeted downstream regulatory proteins Bcl2 and CCND1, which resulted in increased proliferation and G1-S transition. These data provide new insights into the function of EBNA3C in B-cell transformation during GC reaction, and raises the possibility of developing new targeted therapies against EBV-associated cancers.

Abstract 2383: Nicotinamide N-methyltransferase inhibits Protein Phosphatase 2A activity by promoting Y307 phosphorylation

Abstract Recent evidence indicates that suppression of protein phosphatase 2A (PP2A) activity plays an essential role in malignant transformation and cancer cell maintenance. Despite the importance of PP2A as a tumor suppressor in cancer, the mechanisms by which other enzymes regulate PP2A remain largely unknown. We recently identified Nicotinamide N-methyltransferase (NNMT) as a novel regulator of PP2A activity in glioblastoma (GBM). NNMT is a cytosolic N-methyl transferase which utilizes methyl groups from S-Adenosyl methionine (SAM), forming the by-product S-Adenosyl Homocysteine (SAH). PP2A becomes activated following the trimer formation of the three PP2A subunits, which requires the methylation of the catalytic subunit of PP2A (PP2A C) at L309.In cancer, NNMT has been reported to decrease the cellular methylation potential (SAM:SAH) and correspond with decreased PP2A activity. It was hypothesized that the decrease in methylation potential accounts for the decrease in PP2A activity by kinetically disfavoring the methylation of PP2A C. Interestingly, when we overexpressed NNMT in GBM cell lines and used LC-MS/MS (LC-MS Quadrupole Time-of-Flight and LC-MS Triple Quad) to monitor the methylation potential, we discovered that overexpression of NNMT increased methylation potential, however, still lead to a decrease in PP2A activity. As a result, we hypothesized that NNMT suppresses PP2A activity in a methylation-independent manner. In an effort to identify an alternative mechanism by which NNMT decreases PP2A activity, we found that NNMT expression was required for the phosphorylation of PP2A C at residue T307, which inhibits PP2A trimer formation and activation. Further, we found that NNMT expression leads to the constitutive activation of the PP2A target serine/threonine kinases (STKs): Akt, MAPK, and SAPK/JNK. NNMT silencing resulted in the deactivation of these STKs and radiation-induced cellular stress was not sufficient to rescue their activation. This suggests that NNMT-induced PP2A suppression is essential for the activation of these kinases. Overall, this study demonstrates a novel mechanism independent of methylation by which NNMT represses the activity of tumor suppressor PP2A. Citation Format: John R. Jacob, Arnab Chakravarti, Kamalakannan Palanichamy. Nicotinamide N-methyltransferase inhibits Protein Phosphatase 2A activity by promoting Y307 phosphorylation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2383. doi:10.1158/1538-7445.AM2017-2383

Abstract 382: Genome-wide location analysis of DNA adducts in vivo

Abstract DNA adducts are the biochemical consequences of exposure to UV light, carcinogens or DNA-reactive drugs. They play a central role in malignant transformation and the selective killing of cancer cells by chemotherapeutic agents. The functional consequences of DNA adducts is likely to depend on their exact location in the genome with respect to histones and sites where histones and DNA are modified. However, tools that permit precise genome-wide mapping of adduct locations have poor resolution or are too specific to the type of DNA-adduct. Here we present the development of a molecular assay (Ad-Seq) capable of identifying the genomic location of damaged DNA bases in whole cells. Using naked DNA treated with cisplatin (cDDP) or ultra-violet (UV) light as the damaging agents, the strategy relies on differential exonuclease digestion to enrich genome-wide libraries for fragments containing DNA adducts, followed by high-throughput sequencing. Consistent with the expected adduct chemistry, the 5’ end of the reads were enriched in TT, TC or CT di-nucleotides in the UV treated DNA (>4x) and in AG or GG in the cDDP treated DNA (1.5x), suggesting a positive predictive value of 76% and 44% and UV (TT) and cDDP (GG) adduct detection, respectively. Applied in vivo to IMR90 cells, Ad-Seq revealed that the fraction of AG/GG loci was higher in DNA from the cDDP-treated cells at all coverage depths, reaching 1.5x enrichment for the highest depth quartile. This indicates that the method is selective and that even low covered loci show enrichment of AG/GG sequences. The enrichment in purines was limited to 3 nucleotides downstream of the read start site, confirming the high resolution of the exonuclease digestion. A total of 11 x 103 AG/GG loci were identified in replicate in cDDP-treated samples and were absent from untreated controls. With about 60 x103 expected adducts per genome, the current assay therefore captured up to 18% of cDDP adducts. The most covered adduct sites were significantly enriched in the quiescent chromatin domains (depleted of histone modifications, p=6.7x10-31), and depleted in the transcription start sites (p=4.9x10-12), as defined by the ENCODE consortium. This may be reflective of the differences in DNA accessibility or the mechanisms of repair in these distinct regions of the genome. The analysis was performed using the PipeDuct computational package, which was developed to align the sequencing reads and provide general statistics and quality control information of Ad-Seq data. Ad-Seq is therefore a novel, unbiased method to map DNA-adducts and study in vivo the genome-wide specificity of their formation and repair. Citation Format: Brian Woo, Christopher Fang, Paolo Abada, Stephen B. Howell, Olivier Harismendy. Genome-wide location analysis of DNA adducts in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 382. doi:10.1158/1538-7445.AM2017-382

MicroRNA-192 regulates cell proliferation and cell cycle transition in acute myeloid leukemia via interaction with CCNT2.

MicroRNAs (miRNAs) are a class of small non-coding RNAs approximately 18-22 nucleotides in length, which play an important role in malignant transformation. The roles of miR-192 as an oncogene or tumor suppressor in solid tumors have been previously reported. However, little is known about the role of miR-192 in human acute myeloid leukemia. The results of the present study indicate that miR-192 is significantly downregulated in specimens from acute myeloid leukemia patients. Functional assays demonstrated that overexpression of miR-192 in NB4 and HL-60 cells significantly inhibited cell proliferation compared with that in control cells, and induced G0/G1 cell cycle arrest, cell differentiation, and apoptosis in vitro. Dual-luciferase reporter gene assays showed that miR-192 significantly suppressed the activity of a reporter gene containing the wild type 3'-UTR of CCNT2, but it did not suppress the activity of a reporter gene containing mutated 3'-UTR of CCNT2. QRT-PCR and Western blot assays showed that miR-192 significantly downregulated the expression of CCNT2 in human leukemia cells. Exogenous expression of CCNT2 attenuated the cell cycle arrest induced by miR-192 in NB4 and HL-60 cells. Collectively, miR-192 inhibits cell proliferation and induces G0/G1 cell cycle arrest in AML by regulating the expression of CCNT2.

Elimination of LMP1-expressing cells from a monolayer of gastric cancer AGS cells

Epstein-Barr virus (EBV) latently infects malignant epithelial cells in approximately 10% of all gastric cancers. Latent membrane protein 1 (LMP1), an oncogenic protein, plays an important role in malignant transformation in EBV-associated nasopharyngeal carcinoma and B-cell lymphoma; however, its expression has not been detected in EBV-associated gastric cancer. To address why LMP1 has not been detected in EBV-positive gastric tumors, we focused on the interactions between LMP1-positive and -negative cells and stably expressed LMP1 in the gastric cancer cell line AGS. We showed that the number of LMP1-positive cells decreased gradually with each cell passage when the cells were co-cultured with LMP1-negative cells. Time-lapse imaging showed that LMP1-positive cells were eliminated from a monolayer of LMP1-negative cells. Furthermore, LMP1-positive cells stimulated the proliferation of surrounding LMP1-negative cells, but not LMP1-positive cells, via exosome-mediated EGFR activation. Our data indicate that LMP1 expression drives cell competition between LMP1-positive and -negative cells, affecting the behavior of the cells within gastric tissue.

Regulation of intestinal myofibroblasts by KRas-mutated colorectal cancer cells through heparin-binding epidermal growth factor-like growth factor.

In colorectal cancer, gain-of-function mutations in KRas play a critical role in malignant transformation. Tumor growth in colorectal cancer is known to be promoted by the intestinal myofibroblasts (IMFs) that localize adjacent to the cancer cells, but the mechanisms of interaction between KRas-mutated cancer cells and the myofibroblasts remain unclear. Here, we investigated the effects of KRas-mutated cells on the behavior of myofibroblasts by using mouse primary IMFs and cells of an IMF cell line (LmcMF) and a mouse colon epithelial cell line (aMoC1). Conditioned medium (CM) was collected from aMoC1 cells overexpressing a control vector or KRasV12 vector (KRasV12-CM), and the effects of KRasV12-CM on IMFs were analyzed by performing proliferation assays, wound-healing assays, Boyden chamber assays, and western blotting. Whereas KRasV12-CM exerted little effect on the differentiation and proliferation of primary IMFs, the CM promoted migration of both primary IMFs and LmcMF cells. In KRasV12-overexpressing aMoC1 cells, mRNA expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF) was higher than in mock-transfected aMoC1 cells, and HB-EGF promoted the migration of primary IMFs and LmcMF cells. Moreover, KRasV12-CM-induced IMF migration was suppressed by dacomitinib, an inhibitor of HB-EGF receptors. Notably, in LmcMF cells, both KRasV12-CM and HB-EGF activated extracellular signal-regulated kinase (ERK) and c-jun N-terminal kinase (JNK), whereas KRasV12-CM-induced migration of IMFs was suppressed following treatment with either an ERK inhibitor (FR180204) or a JNK inhibitor (SP600125). These results suggest that HB-EGF secreted from KRas-mutated colorectal cancer cells promotes IMF migration through ERK and JNK activation, which, in turn, could support cancer progression.

Caveolin-1 expression in oral lichen planus, dysplastic lesions and squamous cell carcinoma

Caveolin-1(Cav-1), the main part of caveolae structure, is supposed to play a role in pathogenesis of many human tumors. Since oral lichen planus (OLP) is considered as a potential premalignant disease, this study evaluated Cav-1 expression in OLP in comparison with benign hyperkeratosis, dysplastic epithelium and oral squamous cell carcinoma (OSCC), to investigate its possible role in pathogenesis and malignant transformation of OLP. In this cross-sectional retrospective study, immunohistochemical expression of Cav-1 in the epithelial component and stroma was evaluated in 81 samples, including 12 cases of hyperkeratosis, 24 OLP, 22 epithelial dysplasia, and 23 OSCC samples. Correlations between Cav-1 expression and clinicopathological variables were evaluated statistically. Positive Cav-1 staining was found in 58% of OLP, 91% of hyperkeratosis, 100% of epithelial dysplasia, and 95% of OSCC samples. OSCC showed the highest Cav-1 expression and OLP had the lowest (P=0.001). The intensity of staining was significantly increased in stepwise manner from OLP to OSCC (P=0.001). Expression of Cav-1 was related to the grade of samples in OSCC and dysplastic samples (P=0.04). Based on the findings, it was concluded that Cav-1 may play a role in the pathogenesis of OLP and carcinogenesis of SCC, but its role in malignant transformation of OLP is not confirmed. Further studies are needed to evaluate its potential therapeutic function in OLP and SCC.

Chemokine and chemokine receptor patterns in patients with benign and malignant salivary gland tumors: a distinct role for CCR7.

To explore the molecular mechanisms involved in pathophysiology of malignant and benign salivary gland tumors (SGTs), we investigated main tumor-inducing chemokines and chemokine receptors, CXCL12/CXCR4/ACKR3 (CXCR7), CXCR3/CXCL10, CCR5/CCL5, CCL21/CCR7, CCL2, CCR4, CXCR5, CCR6, and CXCL8 in tumor tissues. Parotid tissues were obtained from 30 patients with malignant and benign SGTs. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to determine the mRNA expression pattern of the mentioned chemokines/chemokine receptors and immunohistochemistry (IHC) was performed to verify the expression of CCR7. Expression levels of CCR7 and CCR4 transcripts were higher in the tumor tissues of malignant cases in comparison to benign ones (p=0.03 and 0.02). Immunohistochemistry analysis confirmed that the protein level of CCR7 concurred with the mRNA expression. CCL2 gene transcripts were observed with a higher expression in patients with tumor-free lymph nodes (LN-) and early stages, whereas CCR7 transcript was higher in LN+ and late stages of the disease. A significant inverse correlation was found between CXCL10 transcript and tumor size in benign cases. The mRNA expression of CCR7, CCR4, CXCR3, CCL21, CCL5, and CXCL12 was significantly higher in mucoepidermoid carcinoma in comparison to pleomorphic adenoma subtypes (p<0.05). On the basis of the present study, it was determined that malignant and benign SGTs exhibit a distinct pattern of chemokines and chemokine receptors, which are probably associated with known biological and clinical behaviors of these tumors. Significant increased CCR4 and CCR7 expression in malignant SGTs might play a central role in malignant transformation that introduces them as new targets for cancer immunotherapy.

The TERT promoter mutation incidence is modified by germline TERT rs2736098 and rs2736100 polymorphisms in hepatocellular carcinoma.

Telomerase activation via induction of the catalytic component telomerase reverse transcriptase (TERT) plays essential roles in malignant transformation. TERT promoter-activating mutations were recently identified as a novel mechanism to activate telomerase in hepatocellular carcinoma (HCC) and many other malignancies. In addition, single nucleotide polymorphisms (SNPs) in the TERT rs2736098 and rs2736100 are significantly associated with cancer susceptibility. It is currently unclear whether different germline TERT variants modify TERT promoter mutations. Here we analyzed the TERT promoter status and genotyped the TERT SNPs at rs2736098 and rs2736100 in patients with HCC. Thirty percent of HCCs harbored TERT promoter mutations and there was a significant difference in rs2736098 and rs2736100 genotypes between wt and mutant TERT promoter-bearing HCC tumors (P = 0.007 and 0.018, respectively). For rs2736100, the cancer risk genotype CC was significantly associated with a reduced incidence of TERT promoter mutations compared to AA + AC variants [Odds ratio (OR): 0.181, 95% Confidence interval (CI): 0.0543–0.601, P = 0.004]. The rs2736098_CT genotype was significantly associated with the TERT promoter mutation-positive tumors compared to the TT genotype (OR: 5.391, 95% CI: 1.234–23.553, P = 0.025). These differences in genotype distribution did not differ between patients with a wt TERT promoter and controls. The presence of TERT promoter mutations was not associated with clinico-pathological variables. Taken together, the germline TERT genetic background may significantly affect the onset of TERT promoter mutations in HCCs, which provides a better understanding of HCC-related TERT promoter mutations and telomerase regulation in cancer.

Prognostic significance of β-catenin expression in patients with non-small cell lung cancer: a meta-analysis.

β-catenin is a key component of the canonical Wnt pathway, which plays pivotal roles in malignant transformation and cancer progression. Several studies have reported the clinical significance of the expression level of β-catenin in different subcellular locations. This meta-analysis aimed to assess the prognostic value of β-catenin expression patterns in patients with non-small cell lung cancer (NSCLC). PubMed and Embase databases were searched to identify all articles referring to the association between β-catenin expression level and outcomes of patients of NSCLC up to November 2016. We included eligible studies to summarize the extracted data in terms of pooled hazard ratios (HRs) and their 95% confidence intervals (95% CIs). A total of 24 studies published between 2000 and 2016 were eligible for this meta-analysis. The total number of patients with NSCLC included was 2,807. Pooled HRs and 95% CIs suggested that positive β-catenin expression in membrane was associated with higher survival rates (HR: 0.53; 95% CI: 0.32-0.87), whereas β-catenin expression in cytoplasm and nucleus had unfavorable impacts on survival rates with HR of 1.63 (95% CI: 1.34-1.99) and HR of 3.15 (95% CI: 1.97-5.05), respectively. But, there was no significant association between β-catenin expression in abnormal pattern with prognosis (HR: 1.38; 95% CI: 0.61-3.15). Publication bias was absent in all of the four outcomes. Sensitivity analysis revealed that the results of this meta-analysis were robust. Reduced membranous β-catenin, positive expression of cytoplasmic or nuclear β-catenin is all correlated with poor prognosis, although we did not identify a significant association between abnormal β-catenin expression and clinical outcome of NSCLC patients. The meta-analysis suggested that membranous, cytoplasmic and nuclear β-catenin all could serve as an important prognosticator for patients with NSCLC.

Epidermal Growth Factor Gene Polymorphism in Egyptian Patients with Hepatocellular carcinoma related to Hepatitis C

AIM: Hepatocellular carcinoma (HCC) ranks fifth among the most prevalent cancers worldwide. In Egypt, its incidence has been doubling due to hepatitis C viral (HCV) infection. Epidermal growth factor (EGF) plays an important role in hepatocyte regeneration and had a role in malignant transformation. Single nucleotide polymorphism (SNP) G/G genotype was associated with higher risk for HCC development. This study was done to evaluate the correlation between EGF polymorphism and HCC in patients with HCV. METHODS: Routine investigations for liver cirrhosis and HCC, also EGF genotyping were done on 2 groups; patients with HCV related cirrhosis and patients with newly diagnosed HCC on top of cirrhosis, while the control group performed EGF genotyping only. RESULTS: EGF gene polymorphism 61*G was dominant in HCC patients. The G/G owns the highest concentration when compared with A/A and A/G genotypes, with high statistical significance between the studied groups regarding number and percentage (P < 0.0001). CONCLUSIONS: EGF gene polymorphism 61*G was associated with HCC risk. Moreover, the increased concentration of EGF was associated with G/G genotype.

Expression of Podoplanin in Laryngeal Squamous Cell Carcinoma and Dysplasia.

In human cancers, podoplanin expression and its correlation with tumour invasive potential raise its possible role as a diagnostic and prognostic marker for cancer. To investigate the immunohistochemical expression of podoplanin in laryngeal Squamous Cell Carcinoma (SCC) and dysplasia. This study included a total of 60 archived, formalin fixed, paraffin embedded tissue blocks of 40 cases of laryngeal SCC and 20 cases of dysplastic lesions. The samples were immunohistochemically analysed for podoplanin expression. Podoplanin expression was significantly higher in laryngeal SCC (90%) than laryngeal dysplastic lesions (55%) (p-value=0.002). The expression of podoplanin was significantly increased with the higher grades of dysplasia (p-value=0.016). A significant positive correlation was detected between podoplanin expression in laryngeal SCC and depth of tumour invasion (p-value=0.035), and stage (p-value=0.026). The high expression of podoplanin in laryngeal SCC and its significant correlation with poor prognostic parameters recommends podoplanin as a prognostic marker in laryngeal SCC. In addition, increased podoplanin expression with higher grades of dysplasia, supports its role in malignant transformation and allows us to recommend its evaluation in premalignant lesions.

Glycosylation: a hallmark of cancer?

The hallmarks of cancer are characterized by functional capabilities that allow cancer cells to survive, proliferate and disseminate during the multistep tumorigenesis. Cancer being a cellular disease, changes in cellular glycoproteins play an important role in malignant transformation and cancer progression. The present review summarizes various studies that depicted correlation of glycosylation with tumor initiation, progression and metastasis, which are helpful in early diagnosis, disease monitoring and prognosis. The results are further strengthened by our reports, which depicted alterations in sialylation and fucosylation in different cancers. Alterations in glycosyltransferases are also involved in formation of various tumor antigens (e.g. Sialyl Lewis x) which serves as ligand for the cell adhesion molecule, selectin which is involved in adhesion of cancer cells to vascular endothelium and thus contributes to hematogenous metastasis. Increased glycosylation accompanied by alterations in glycosyltranferases, glycosidases, glycans and mucins (MUC)s are also involved in loss of E-cadherin, a key molecule implicated in metastatic dissemination of cells. The present review also summarizes the correlation of glycosylation with all the hallmarks of cancer. The enormous progress in the design of novel inhibitors of pathway intermediates of sialylation and fucosylation can prove wonders in combating the dreadful disease. The results provide the evidence that altered glycosylation is linked to tumor initiation, progression and metastasis. Hence, it can be considered as a new hallmark of cancer development and strategies to develop novel glycosylation targeted molecules should be strengthened.