Early-onset colorectal cancer patients without family history are "at very low risk" for lynch syndrome

Regulation of cancer progression by CK2: an emerging therapeutic target

Casein kinase II (CK2) is an enzyme with pleiotropic kinase activity that catalyzes the phosphorylation of lots of substrates, including STAT3, p53, JAK2, PTEN, RELA, and AKT, leading to the regulation of diabetes, cardiovascular diseases, angiogenesis, and tumor progression. CK2 is observed to have high expression in multiple types of cancer, which is associated with poor prognosis. CK2 holds significant importance in the intricate network of pathways involved in promoting cell proliferation, invasion, migration, apoptosis, and tumor growth by multiple pathways such as JAK2/STAT3, PI3K/AKT, ATF4/p21, and HSP90/Cdc37. In addition to the regulation of cancer progression, increasing evidence suggests that CK2 could regulate tumor immune responses by affecting immune cell activity in the tumor microenvironment resulting in the promotion of tumor immune escape. Therefore, inhibition of CK2 is initially proposed as a pivotal candidate for cancer treatment. In this review, we discussed the role of CK2 in cancer progression and tumor therapy.

Hepatocellular carcinoma patients serum modulates the regenerative capacities of adipose mesenchymal stromal cells

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers causing the highest mortality rate worldwide. Treatment options of surgery, radiation, cytotoxic drugs and liver transplantation suffer significant side effects and a high frequency of relapse. Stem cell therapy has been proposed as a new effective therapy, however, controversial reports are emerging on the role of mesenchymal stem cells in cancer. In this work, we aimed to assess the regenerative capacities of adipose mesenchymal stem cells when exposed to serum from HCC patients, by assessing the effect of the sera on modulating the regenerative capacities of h-AMSCs and the cancer properties in HCC cells. This will pave the way for maximizing the efficacy of MSCs in cancer therapy. Our data show that HCC serum-treated hA-MSCs suffered oncogene-induced senescence as shown by their altered morphology and ameliorated proliferation and differentiation. The cells were enlarged with small irregular nuclei, swollen rough endoplasmic reticulum cisternae, and aging lysosomes typified by dark residual bodies. HCC serum-treated Huh-7 cancer cells on the other hand displayed higher tumor aggressiveness as depicted by altered morphology, increased cellular proliferation and migration, and decreased percentage of early and late apoptotic cells. Our findings provide evidence that exposure of hA-MSCs to the serum of HCC patients decreases their regenerative capacities and should be considered when employed as a potential therapy in HCC patients.

Bromelain: a review of its mechanisms, pharmacological effects and potential applications

The utilization of plant-derived supplements for disease prevention and treatment has long been recognized because of their remarkable potential. Ananas comosus, commonly known as pineapple, produces a group of enzymes called bromelain, which contains sulfhydryl moieties. Recent studies have shown that bromelain exhibits a wide range of activities, including anti-inflammatory, anti-diabetic, anti-cancer, and anti-rheumatic properties. These properties make bromelain a promising drug candidate for the treatment of various diseases. The anti-inflammatory activity of bromelain has been shown to be useful in treating inflammatory conditions such as osteoarthritis, rheumatoid arthritis, and asthma, whereas the anti-cancer activity of bromelain is via induction of apoptosis, inhibition of angiogenesis, and enhancement of the body's immune response. The anti-diabetic property of bromelain is owing to the improvement in glucose metabolism and reduction in insulin resistance. The therapeutic potential of bromelain has been investigated in numerous preclinical and clinical studies and a number of patents have been granted to date. Various formulations and delivery systems are being developed in order to improve the efficacy and safety of this molecule, including the microencapsulated form to treat oral inflammatory conditions and liposomal formulations to treat cancer. The development of novel drug delivery systems and formulations has further ameliorated the therapeutic potential of bromelain by improving its bioavailability and stability, while reducing the side effects. This review intends to discuss various properties and therapeutic applications of bromelain, along with its possible mechanism of action in treating various diseases. Recent patents and clinical trials concerning bromelain have also been covered.

Perturbing plasma membrane lipid: a new paradigm for tumor nanotherapeutics

Cancer is generally considered a result of genetic mutations that cause epigenetic changes, leading to anomalous cellular behavior. Since 1970s, an increasing understanding of the plasma membrane and specifically the lipid alterations in tumor cells have provided novel insights for cancer therapy. Moreover, the advances in nanotechnology offer a potential opportunity to target the tumor plasma membrane while minimizing side effects on normal cells. To further develop membrane lipid perturbing tumor therapy, the first section of this review demonstrates the association between plasma membrane physicochemical properties and tumor signaling, metastasis, and drug resistance. The second section highlights existing nanotherapeutic strategies for membrane disruption, including lipid peroxide accumulation, cholesterol regulation, membrane structure disruption, lipid raft immobilization, and energy-mediated plasma membrane perturbation. Finally, the third section evaluates the prospects and challenges of plasma membrane lipid perturbing therapy as a therapeutic strategy for cancers. The reviewed membrane lipid perturbing tumor therapy strategies are expected to bring about necessary changes in tumor therapy in the coming decades.

Distinct Molecular Profiles of Sporadic Early-Onset Colorectal Cancer: A Population-Based Cohort and Systematic Review

BACKGROUND AND AIMS

The observed increase in the incidence of early-onset colorectal cancer (EOCRC) is being driven by sporadic cases, but the molecular characteristics of these tumors are not fully understood. Our objective was to investigate the prevalence of microsatellite instability (MSI) and selected mutations in sporadic EOCRC, and their association with survival.

METHODS

Firstly, we compared the prevalence of molecular characteristics and survival within a population-based cohort study of 652 stage II and III colon cancer patients in Northern Ireland, comparing sporadic early-onset (<50 years, n = 35) with older (60-69 years, n = 179) patients. Secondly, a systematic review for studies reporting the prevalence of MSI, mismatch repair deficiency (dMMR), or BRAF, KRAS, NRAS, PIK3CA, and TP53 mutations in sporadic EOCRC was conducted. A meta-analysis was performed to calculate pooled estimates of the prevalence of molecular features in sporadic EOCRC.

RESULTS

Firstly, within the cohort study, EOCRC patients did not have a significantly increased risk of colorectal cancer-specific death (adjusted hazard ratio 1.20; 95% confidence interval [CI] 0.61-2.39) compared with 60- to 69-year-olds. Second, 32 studies were included in the systematic review. The pooled analysis estimated a prevalence of 10% (95% CI 7%-14%) for MSI high/dMMR in sporadic EOCRC. BRAF and KRAS mutations had a prevalence of 1% (95% CI 0%-3%) and 32% (95% CI 23%-40%), respectively.

CONCLUSION

The molecular characteristics of sporadic EOCRC differ from those of cancers in older adults, particularly regarding reduced prevalence of BRAF mutations. Ten percent of sporadic EOCRC display MSI high/dMMR. Further studies are needed to address survival in sporadic EOCRC cases and whether molecular profiles influence EOCRC outcomes in this patient group.

lncRNA-disease association prediction based on matrix decomposition of elastic network and collaborative filtering

In recent years, with the continuous development and innovation of high-throughput biotechnology, more and more evidence show that lncRNA plays an essential role in biological life activities and is related to the occurrence of various diseases. However, due to the high cost and time-consuming of traditional biological experiments, the number of associations between lncRNAs and diseases that rely on experiments to verify is minimal. Computer-aided study of lncRNA-disease association is an important method to study the development of the lncRNA-disease association. Using the existing data to establish a prediction model and predict the unknown lncRNA-disease association can make the biological experiment targeted and improve its accuracy of the biological experiment. Therefore, we need to find an accurate and efficient method to predict the relationship between lncRNA and diseases and help biologists complete the diagnosis and treatment of diseases. Most of the current lncRNA-disease association predictions do not consider the model instability caused by the actual data. Also, predictive models may produce data that overfit is not considered. This paper proposes a lncRNA-disease association prediction model (ENCFLDA) that combines an elastic network with matrix decomposition and collaborative filtering. This method uses the existing lncRNA-miRNA association data and miRNA-disease association data to predict the association between unknown lncRNA and disease, updates the matrix by matrix decomposition combined with the elastic network, and then obtains the final prediction matrix by collaborative filtering. This method uses the existing lncRNA-miRNA association data and miRNA-disease association data to predict the association of unknown lncRNAs with diseases. First, since the known lncRNA-disease association matrix is very sparse, the cosine similarity and KNN are used to update the lncRNA-disease association matrix. The matrix is then updated by matrix decomposition combined with an elastic net algorithm, to increase the stability of the overall prediction model and eliminate data overfitting. The final prediction matrix is then obtained through collaborative filtering based on lncRNA.Through simulation experiments, the results show that the AUC value of ENCFLDA can reach 0.9148 under the framework of LOOCV, which is higher than the prediction result of the latest model.

Non-invasive diagnostic potential of microRNA-203 in liquid biopsy of urothelial carcinoma of bladder

Increased CD44 antigen activity has been reported in recurrent cases of UBC. To date, no reliable biomarker is available with high significance and specificity for non-invasive detection of UBC. This study aimed to identify a CD44-linked microRNAs (miRNAs) (miR-9, miR-34a, miR-203) for non-invasive diagnosis of bladder cancer from other urinary tract malignancies. The expression of CD44-linked miRNAs was examined in serum, urine, and tissue specimens of Indian UBC patients (N = 25). For this purpose, healthy subjects (N = 25) and benign prostatic hyperplasia (BPH) (N = 10) patients were taken as controls. The relative expression of miRNAs was analyzed in serum, urine, and tissue samples using real-time quantitative reverse transcription PCR (qRT-PCR). The diagnostic potential of these miRNAs was accessed by plotting ROC curve. Increased miR-9 expression was observed in serum of UBC patients than healthy and BPH controls. In UBC patients, miR-34a expression was lower than healthy controls but non-significant as compared to BPH. miR-203 expression was considerably higher in serum of UBC patients but non-significant as compared to BPH controls. miR-203 was found to be considerably higher in urine samples from UBC patients as compared to BPH and healthy controls. The diagnostic potential of these miRNAs was evaluated using the ROC curve. Higher miR-203 levels in the urine of Indian UBC patients demonstrate its non-invasive diagnostic ability out of the three miRNAs studied. Our results characterize the non-invasive diagnostic potential of CD44-linked miR-203 in the urine of Indian UBC patients, which could be utilized in clinical settings in future after validation in larger patient cohort.

Organochlorine pesticides, oxidative stress biomarkers, and leukemia: a case-control study

Exposure to pesticides has been linked to an elevated risk of leukemia. The present research aimed to evaluate the relationship between organochlorine (OC) pesticides and biomarkers of oxidative stress in patients with leukemia. This work was conducted on 109 patients with leukemia and 109 healthy controls. The serum concentrations of seven derivatives of OCs including alpha-hexachlorocyclohexane (HCH), beta-HCH, gamma-HCH, 2,4-dichlorodiphenyltrichloroethane (DDT), 4,4-DDT, 2,4-dichlorodiphenyldichloroethylene (DDE), and 4,4-DDE along with acetylcholinesterase (AChE), glutathione peroxidase (GPx), superoxide dismutase (SOD), paraoxonase-1 (PON1), and catalase (CAT) activities as well as total antioxidant capacity (TAC), nitric oxide (NO), protein carbonyl (PC), and malondialdehyde (MDA) levels were measured in all the subjects. Levels of OCs were remarkably higher in patients with leukemia compared with the controls (p<0.05). In addition, levels of SOD, AChE, GPx, PON1, and TAC were remarkably lower in patients with leukemia compared with controls (p<0.05). In contrast, MDA, NO, and PC concentrations were higher in patients with leukemia than in the controls (p<0.05). Moreover, the serum level of 4,4-DDE was negatively associated with GPx activity (p=0.038). Our findings suggest that OCs may play a role in the development of leukemia by disrupting the oxidant/antioxidant balance.

Association Between Tumor Mutation Profile and Clinical Outcomes Among Hispanic-Latino Patients With Metastatic Colorectal Cancer

In the United States, CRC is the third most common type of cancer and the second leading cause of cancer-related death. Although the incidence of CRC among the Hispanic population has been declining, recently, a dramatic increase in CRC incidents among HL younger than 50 years of age has been reported. The incidence of early-onset CRC is more significant in HL population (45%) than in non-Hispanic Whites (27%) and African-Americans (15%). The reason for these racial disparities and the biology of CRC in the HL are not well understood. We performed this study to understand the biology of the disease in HL patients. We analyzed formalin-fixed paraffin-embedded tumor tissue samples from 52 HL patients with mCRC. We compared the results with individual patient clinical histories and outcomes. We identified commonly altered genes in HL patients (APC, TP53, KRAS, GNAS, and NOTCH). Importantly, mutation frequencies in the APC gene were significantly higher among HL patients. The combination of mutations in the APC, NOTCH, and KRAS genes in the same tumors was associated with a higher risk of progression after first-line of chemotherapy and overall survival. Our data support the notion that the molecular drivers of CRC might be different in HL patients.

rs2671655 single nucleotide polymorphism modulates the risk for gastric cancer in Helicobacter pylori-infected individuals: a genome-wide association study in the Korean population

OBJECTIVE

To identify genetic variations which is associated with gastric cancer (GC) risk according to Helicobacter pylori infection.

METHODS

This study incorporated 527 GC patients and 441 controls from a cohort at Seoul National University Bundang Hospital. The associations between GC risk and single nucleotide polymorphisms were calculated, stratified by H. pylori status, adjusting for age, sex, and smoking. mRNA expression from non-cancerous gastric mucosae was evaluated using reverse transcription quantitative polymerase chain reaction.

RESULTS

In the entire cohort, genome-wide association study showed no significant variants reached the genome-wide significance level. In the H. pylori-positive group, rs2671655 (chr17:47,468,020;hg19, GH17J049387 enhancer region) was identified at a genome-wide significance level, which was more pronounced in diffuse type GC. There was no significant variant in the H. pylori-negative group, indicating the effect modification of rs2671655 by H. pylori. Among the target genes of GH17J049387 enhancer (PHB1, ZNF652 and SPOP), PHB1 mRNA was expressed more in cases than in controls, who were not affected by H. pylori. By contrast, an increase in ZNF652 and SPOP in GC was observed only in the H. pylori-negative group (P < 0.05). Mediation analysis showed that PHB1 (P = 0.0238) and SPOP (P = 0.0328) mediated the effect of rs2671655 on GC risk. The polygenic risk score was associated with the number of rs2671655 risk alleles only in the H. pylori-positive group (P = 0.0112).

CONCLUSION

After H. pylori infection, rs2671655 may increase GC risk, especially in diffuse-type GC, by regulating the expression of several genes that consequently modify susceptibility to GC.

Runt related transcription factor-1 plays a central role in vessel co-option of colorectal cancer liver metastases

Colorectal cancer liver metastasis (CRCLM) has two major histopathological growth patterns: angiogenic desmoplastic and non-angiogenic replacement. The replacement lesions obtain their blood supply through vessel co-option, wherein the cancer cells hijack pre-existing blood vessels of the surrounding liver tissue. Consequentially, anti-angiogenic therapies are less efficacious in CRCLM patients with replacement lesions. However, the mechanisms which drive vessel co-option in the replacement lesions are unknown. Here, we show that Runt Related Transcription Factor-1 (RUNX1) overexpression in the cancer cells of the replacement lesions drives cancer cell motility via ARP2/3 to achieve vessel co-option. Furthermore, overexpression of RUNX1 in the cancer cells is mediated by Transforming Growth Factor Beta-1 (TGFβ1) and thrombospondin 1 (TSP1). Importantly, RUNX1 knockdown impaired the metastatic capability of colorectal cancer cells in vivo and induced the development of angiogenic lesions in liver. Our results confirm that RUNX1 may be a potential target to overcome vessel co-option in CRCLM.

Lung cancer and epithelial-mesenchymal transition

Lung cancer (LC) is a leading cause of cancer-related death worldwide. Epithelial-mesenchymal transition (EMT) is a well-known phenomenon that promotes the invasive and metastatic capabilities of LC. Especially, EMT is assumed to be a pivotal mechanism for tumor cell invasion and metastasis, thereby limiting the efficacy of surgery and medical treatments, resulting in poor patient prognoses. Thus, the elucidation and reversal of EMT could provide changes in therapeutic strategies for LC. To overcome the limitations of currents treatment regimens for LC, it is important for surgeons to be familiar with this complex tumor characteristic. In this review, the activating signaling pathways underlying EMT and the associated tumor phenotypes are briefly described.

Transcriptome analysis revealed CENPF associated with glioma prognosis

Gliomas are common malignant tumors of the central nervous system. Despite the surgical resection and postoperative radiotherapy and chemotherapy, the prognosis of glioma remains poor. Therefore, it is important to reveal the molecular mechanisms that promotes glioma progression. Microarray datasets were obtained from the Gene Expression Omnibus (GEO) database. The GEO2R tool was used to identify 428 differentially expressed genes (DEGs) and a core module from three microarray datasets. Heat maps were drawn based on DEGs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed using the DAVID database. The core module was significantly involved in several KEGG pathways, such as "cell cycle", "viral carcinogenesis", "progesterone-mediated oocyte maturation", "p53 signaling pathway". The protein-protein interaction (PPI) networks and modules were built using the STRING database and the MCODE plugin, respectively, which were visualized using Cytoscape software. Identification of hub genes in the core module using the CytoHubba plugin. The top modular genes AURKA, CDC20, CDK1, CENPF, and TOP2A were associated with glioma development and prognosis. In the Human Protein Atlas (HPA) database, CDC20, CENPF and TOP2A have significant protein expression. Univariate and multivariate cox regression analysis showed that only CENPF had independent influencing factors in the CGGA database. GSEA analysis found that CENPF was significantly enriched in the cell cycle, P53 signaling pathway, MAPK signaling pathway, DNA replication, spliceosome, ubiquitin-mediated proteolysis, focal adhesion, pathway in cancer, glioma, which was highly consistent with previous studies. Our study revealed a core module that was highly correlated with glioma development. The key gene CENPF and signaling pathways were identified through a series of bioinformatics analysis. CENPF was identified as a candidate biomarker molecule.

Preparation and biomedical application of injectable hydrogels

The preparation of multifunctional injectable hydrogels, as well as the classification of injectable hydrogels according to different functions, most summarize the applications of injectable hydrogels in different biomedical fields.

Inhibition of urinary bladder cancer cell proliferation by silibinin

Silibinin, a natural compound extracted from milk thistle, has demonstrated antitumor properties in urinary bladder cancer cells; however, the role of TP53 gene in these effects is unclear. In order to better understand the molecular and antiproliferative mechanisms of this compound, urinary bladder cancer cells with different TP53 gene status, RT4 (low-grade tumor, wild TP53 gene), 5637 (high-grade tumor, Grade 2, mutated TP53 gene), and T24 (high-grade tumor, Grade 3, mutated TP53 gene) were treated with several concentrations of silibinin (1, 5, 10, 50, 100, and 150 μM). Cytotoxicity, prooxidant effect, morphological changes, cell migration, cell cycle progression, global methylation profile, and relative expression of HOXB3, c-MYC, PLK1, SMAD4, SRC, HAT, HDAC, and RASSF1A genes were evaluated. The silibinin presented cytotoxic and prooxidant effects in the three cell lines. In mutated TP53 cells, significant interference in cell migration and cell cycle arrest at the G2/M phase was observed. Additionally, silibinin induced global DNA hypomethylation in the highest grade tumor cells. For wild-type TP53 cells, a sub-G1 apoptotic population was present. Furthermore, there was modulation of gene expression responsible for cell growth (SMAD and c-MYC), migration (SRC), cell cycle kinetics (PLK1), angiogenesis (HOXB3), and of genes associated with epigenetic events such as DNA acetylation (HAT) and deacetylation (HDAC). In conclusion, the silibinin inhibited the urinary bladder tumor cell proliferation independently of TP53 status; however, cell cycle effects, gene expression changes, and alteration of cell migration are dependent on TP53 status. © 2020 Wiley Periodicals, Inc.

Old vs new: Risk factors predicting early onset colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second leading cause of all cancer related deaths in the United States and Europe. Although the incidence has been decreasing for individuals’ ≥ 50, it has been on the rise for individuals < 50.

AIM

To identify potential risk factors for early-onset CRC.

METHODS

A population-based cohort analysis using a national database, Explorys, screened all patients with an active electronic medical record from January 2012 to December 2016 with a diagnosis of CRC. Subgroups were stratified based on age (25 – 49 years vs ≥ 50 years). Demographics, comorbidities, and symptom profiles were recorded and compared between both age groups. Furthermore, the younger group was also compared with a control group consisting of individuals aged 25-49 years within the same timeframe without a diagnosis of CRC. Twenty-data points for CRC related factors were analyzed to identify potential risk factors specific to early-onset CRC.

RESULTS

A total of 68860 patients were identified with CRC, of which 5710 (8.3%) were younger than 50 years old, with 4140 (73%) between 40-49 years of age. Multivariable analysis was reported using odds ratio (OR) with 95%CI and demonstrated that several factors were associated with an increased risk of CRC in the early-onset group versus the later-onset group. These factors included: African-American race (OR 1.18, 95%CI: 1.09-1.27, P < 0.001), presenting symptoms of abdominal pain (OR 1.82, 95%CI: 1.72-1.92, P <0.001), rectal pain (OR 1.50, 95%CI: 1.28-1.77, P < 0.001), altered bowel function (OR 1.12, 95%CI: 1.05-1.19, P = 0.0005), having a family history of any cancer (OR 1.78, 95%CI: 1.67-1.90, P < 0.001), gastrointestinal (GI) malignancy (OR 2.36, 95%CI: 2.18-2.55, P < 0.001), polyps (OR 1.41, 95%CI: 1.08-1.20, P < 0.001), and obesity (OR 1.14, 95%CI: 1.08-1.20, P < 0.001). Comparing the early-onset cohort versus the control group, factors that were associated with an increased risk of CRC were: male gender (OR 1.34, 95%CI: 1.27-1.41), P < 0.001), Caucasian (OR 1.48, 95%CI: 1.40-1.57, P < 0.001) and African-American race (OR 1.25, 95%CI: 1.17-1.35, P < 0.001), presenting symptoms of abdominal pain (OR 4.73, 95%CI: 4.49-4.98, P < 0.001), rectal pain (OR 7.48, 95%CI: 6.42-8.72, P < 0.001), altered bowel function (OR 5.51, 95%CI: 5.19-5.85, P < 0.001), rectal bleeding (OR 9.83, 95%CI: 9.12-10.6, P < 0.001), weight loss (OR 7.43, 95%CI: 6.77-8.15, P < 0.001), having a family history of cancer (OR 11.66, 95%CI: 10.97-12.39, P < 0.001), GI malignancy (OR 28.67, 95%CI: 26.64-30.86, P < 0.001), polyps (OR 8.15, 95%CI: 6.31-10.52, P < 0.001), tobacco use (OR 2.46, 95%CI: 2.33-2.59, P < 0.001), alcohol use (OR 1.71, 95%CI: 1.62-1.80, P < 0.001), presence of colitis (OR 4.10, 95%CI: 3.79-4.43, P < 0.001), and obesity (OR 2.88, 95%CI: 2.74-3.04, P < 0.001).

CONCLUSION

Pending further investigation, these potential risk factors should lower the threshold of suspicion for early CRC and potentially be used to optimize guidelines for early screening.

Aquaporins in cancer development: opportunities for bioinorganic chemistry to contribute novel chemical probes and therapeutic agents

Aquaporins (AQPs) are membrane proteins allowing permeation of water, glycerol & hydrogen peroxide across biomembranes, and playing an important role in water homeostasis in different organs, exocrine gland secretion, urine concentration, skin moisturization, fat metabolism and neural signal transduction. Notably, a large number of studies showed that AQPs are closely associated with cancer biological functions and expressed in more than 20 human cancer cell types. Furthermore, AQP expression is positively correlated with tumour types, grades, proliferation, migration, angiogenesis, as well as tumour-associated oedema, rendering these membrane channels attractive as both diagnostic and therapeutic targets in cancer. Recent developments in the field of AQPs modulation have identified coordination metal-based complexes as potent and selective inhibitors of aquaglyceroporins, opening new avenues in the application of inorganic compounds in medicine and chemical biology. The present review is aimed at providing an overview on AQP structure and function, mainly in relation to cancer. In this context, the exploration of coordination metal compounds as possible inhibitors of aquaporins may open the way to novel chemical approaches to study AQP roles in tumour growth and potentially to new drug families. Thus, we describe recent results in the field and reflect upon the potential of inorganic chemistry in providing compounds to modulate the activity of "elusive" membrane targets as the aquaporins.

Prevalence and clinicopathological characteristics of mismatch repair-deficient colorectal carcinoma in early onset cases as compared with late-onset cases: a retrospective cross-sectional study in Northeastern Iran

OBJECTIVES

Lynch syndrome (LS), a genetically inherited autosomal disorder, increases the incidence of colorectal carcinoma (CRC). We aimed to perform a universal strategy to assess the prevalence and clinicopathological characteristics of early onset CRCs at high risk of LS versus late-onset ones in the Iranian population.

SETTING

A local population-based study from Northeastern Iran.

PARTICIPANTS

321 consecutive CRCs and pathology specimen screened between 2013 and 2016.

PRIMARY AND SECONDARY OUTCOME MEASURES

Retrospectively, information regarding the clinical criteria was obtained by interviewing the patients with CRC or, their families. Pathologists tested tumours with immunohistochemistry (IHC) staining of four mismatch repair (MMR) proteins (MLH1, MSH2, MSH6 and PMS2). Tumours with absent IHC staining of MLH1 were tested for BRAF mutations to exclude sporadic CRCs. Prevalence of early onset CRCs at high risk of LS and familial CRC type X were assessed as primary and secondary outcome measures, respectively.

RESULTS

Of 321 CRCs (13/123 (10.57%), early onset vs 21/198 (10.6%) late-onset) were detected to be MMR-deficient (dMMR). Nine early onset cases and 14 late-onset ones with a loss of MLH1 underwent testing for the BRAF mutation, none of the early onset and four (2.02%) late-onset were recognised as sporadic. The difference in the outcome of IHC-analysis between early and late-onset CRCs at high risk of LS was not statistically significant (p=0.34). Majority of the suspected LS tumours from early onset patients had arisen in distal part (8/11 (72.72%) vs 8/14 (57.14%)), all of which were occurred in the rectum or sigmoid.

CONCLUSION

Clinically, these findings suggest that in case of limitation for BRAF testing, the practitioner in Iran may consider managing early onset dMMR cases like LS until access to BRAF testing becomes available to them, before germline testing to accurately diagnose LS.

Early onset sporadic colorectal cancer: Worrisome trends and oncogenic features

Early onset colorectal cancers, defined as arising before 50 years of age, are a growing health hazard in western and eastern countries alike. The incidence of colon and rectal cancers in young individuals is projected to increase by as much as 90% and 140%, respectively, by 2030. Although several known cancer risk factors (e.g. smoking, alcohol, dietary habits) have been investigated, there is no single compelling explanation for this epidemiological trend. While some early onset colorectal cancers have been associated with germline mutations in cancer predisposition genes, genetic syndromes are implicated in only a fraction of these cancers (20%) and do not explain the rising incidence. Colorectal neoplasms develop through microsatellite instability or chromosomal instability pathways, with most of the early onset colorectal cancers exhibiting microsatellite stable phenotypes. Genome-wide hypomethylation is a feature of a subgroup of early onset cancers, which appears to be correlated with chromosomal instability and poor prognosis.

Microsatellite instability and protein expression of MLH1 and MSH2 genes in young Mexican patients less than 50 years of age diagnosed with colorectal cancer

Diagnosis of colorectal cancer in patients under 45 years old should alert us to possible hereditary forms of this neoplasia. Most cases of hereditary colorectal cancer correspond to Lynch syndrome which is caused by mutations in DNA mismatch repair genes, particularly MLH1 and MSH2. The dysfunction is associated with microsatellite instability which occurs in 95% cases of this syndrome and in 15% of sporadic colorectal cancer. In sporadic colon tumors, downregulation of MLH1 is observed in cases with the BRAF V600E variant, which induces hypermetylation of the MLH1 promoter. Mutation screening for hereditary cancer has impacted the diagnosis, genetic counseling, and early tumor detection in families affected by hereditary colorectal cancer syndromes but mutation screening technologies are seldom available in public health care centers in developing countries. This study aimed to describe immunohistochemistry and microsatellite instability abnormalities in tumor samples archived in a public hospital in Mexico. Paraffin-embedded samples of patients with colorectal cancer, diagnosed at under 50 years old, were studied to analyze correlations among clinical variables, MLH1 and MSH2 protein expression (immunohistochemistry), microsatellite instability (fluorescent PCR-based assay), and BRAF V600E variant (real time PCR). Forty-seven tumor specimens from patients with TNM stage II and above were analyzed. Tumors were mainly located in the proximal colon segment and displayed histologic intestinal variety and infiltration to serosa. Twenty samples showed decreased expression of mismatch repair proteins and 10 of these presented microsatellite instability (7 high and 3 low instability patterns, respectively). There were no instances of BRAF V600E mutation found. Altered MLH1 or MSH2 expression was found in 42.5% of the samples and microsatellite instability was observed in 21.3% of the tumors. These results suggested that about a fifth of the patients were candidates for family assessment and genetic counseling.

Retracted Article: Overexpression of PCDH8 inhibits proliferation and invasion, and induces apoptosis in papillary thyroid cancer cells

Protocadherin8 (PCDH8), a member of the protocadherin (PCDH) family, is involved in the progression of several types of cancers. However, the expression and biological roles of PCDH8 in papillary thyroid carcinoma (PTC) remain largely unknown. Therefore, in the present study, we detected the expression of PCDH8 in human PTC tissues and cell lines, and evaluated its role in PTC cells. Our results demonstrated that PCDH8 was lowly expressed in human PTC tissues and cell lines. In addition, ectopic expression of PCDH8 efficiently inhibited the proliferation, migration and invasion of PTC cells, as well as prevented the epithelial-mesenchymal transition (EMT) phenotype in PTC cells. Furthermore, PCDH8 efficiently induced apoptosis and autophagy in PTC cells. Mechanistically, overexpression of PCDH8 significantly prevented the activation of the Wnt/β-catenin pathway in PTC cells. Taken together, these findings showed that overexpression of PCDH8 inhibits proliferation and migration/invasion, and induces apoptosis of PTC cells through the Wnt/β-catenin signaling pathway.

Protocadherin8 (PCDH8), a member of the protocadherin (PCDH) family, is involved in the progression of several types of cancers.

MicroRNA-294 Promotes Cellular Proliferation and Motility through the PI3K/AKT and JAK/STAT Pathways by Upregulation of NRAS in Bladder Cancer

In our study we examined the role of microRNA-294 (miR-294) in bladder cancer and related mechanisms. Real-time polymerase chain reaction (RT-PCR) was performed to determine the expression level of miR-294. Western blot was used to determine the expression of NRAS, mainly factors in the PI3K/AKT and JAK/STAT pathways. Cell counting kit-8 assay, clonogenic assay, wound-healing assay, transwell and flow cytometry were used to explore, respectively, cell proliferation, survival, migration, invasion, and apoptosis of bladder cancer cell line T24. The expressions of miR-294 in bladder cancer cells including J82, HT1376, T24, and SW780 were significantly increased compared to those in human bladder epithelium cells (both HCV29 and SV-HUC-1). The proliferation rate, surviving fraction, migration, and invasion of T24 cells in miR-294 mimetic transfected group were significantly increased, while they were significantly decreased by miR-294 inhibitor transfection. Moreover, miR-294 suppression could increase the apoptotic rate of T24 cells. In addition, drug resistance of T24 cells to cisplatin was increased in miR-294 mimetic-treated group, while it was decreased by miR-294 inhibitor compared to empty control. Overexpression of miR-294 could upregulate NRAS expression in T24 cells and activate PI3K/AKT and JAK/STAT pathways. We found that miR-294 expression was positively related with proliferation and motility of T24 cells. Moreover, miR-294 suppression could promote the sensitivity of T24 cells to cisplatin. We also found miR-294 could upregulate NRAS and activate the PI3K/AKT and JAK/STAT pathways in T24 cells.

Identification of a six-lncRNA signature associated with recurrence of ovarian cancer

Ovarian cancer (OvCa) is the leading cause of death among all gynecological malignancies, and recurrent OvCa is almost always incurable. In this study, we developed a signature based on long non-coding RNAs (lncRNAs) associated with OvCa recurrence to facilitate personalized OvCa therapy. lncRNA expression data were extracted from GSE9891 and GSE30161. LASSO (least absolute shrinkage and selection operator) penalized regression was used to identify an lncRNA-based signature using the GSE9891 training cohort. The signature was then validated in GSE9891 internal and GSE30161 external validation cohorts. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to explore the possible functions of identified lncRNAs. A six-lncRNA signature (RUNX1-IT1, MALAT1, H19, HOTAIRM1, LOC100190986 and AL132709.8) was identified in the training cohort and validated in internal and external validation cohorts using the LASSO method (P < 0.05). This signature was also independent of other clinical factors according to multivariate and sub-group analyses. The identified lncRNAs are involved in cancer-related biological processes and pathways. We selected a highly reliable signature based on six lncRNAs associated with OvCa recurrence. This six-lncRNA signature is a promising method to personalize ovarian cancer therapy and may improve patient quality of life quality according to patients' condition in the future.

Prevalence and clinicopathologic/molecular characteristics of mismatch repair-deficient colorectal cancer in the under-50-year-old Japanese population

PURPOSE

To clarify the prevalence and clinicopathologic/molecular characteristics of mismatch repair (MMR)-deficient colorectal cancer in the young Japanese population.

METHODS

Immunohistochemical analyses for MMR proteins (MLH1, MSH2, MSH6, and PMS2) were performed in formalin-fixed paraffin-embedded sections prepared from the resected CRC specimens of 119 consecutive patients aged <50 years old, who underwent resection of the primary tumor at our institution between 1996 and 2015. Analyses for somatic BRAF V600E mutation, somatic hypermethylation of the MLH1 promoter, and germline MMR gene mutations were undertaken where indicated.

RESULTS

MMR protein loss was found in 10 patients (8.4%), 7 (5.9%) of whom were subsequently identified to have Lynch syndrome (LS). The remaining 3 patients were categorized as having sporadic MMR-deficient CRC (n = 2) or "possible LS (n = 1)". In multivariate logistic regression analysis, the presence of tumor-infiltrating lymphocytes (P < 0.01), right-sided location of the tumor (P = 0.01), and a history of LS-associated tumors in the first-degree relatives (P < 0.01) were identified as independent factors predictive of MMR-deficient CRC.

CONCLUSION

These results are of value in the clinical management of patients with the early onset CRC under circumstances where universal tumor screening approaches for LS are still not available, like in Japan.

Left-sided early onset colorectal carcinomas: A sporadic neoplasm with aggressive behavior

BACKGROUND

Early onset (≤50y) colorectal carcinomas (EO-CRCs) are increasing in incidence according to epidemiological data. We investigated clinical-pathological, molecular features and outcomes of 62 left sided EO-CRCs (EOLS-CRCs) and compared them to a group of late onset (≥65) LS-CRCs (LOLS-CRCs).

MATERIALS AND METHODS

Samples were evaluated for pathological features and microsatellite instability (MSI). Overall survival (OS), disease free survival (DFS) and disease specific survival were evaluated in both groups.

RESULTS

Five out 62 (8%) EOLS-CRCs showed MSI phenotype. Interestingly these cases were aged 26-39y. Most EOLS-CRCs present at advanced stage and this was statistically significant when compared to LOLS-CRCs. OS was better in EOLS-CRCs whilst DFS showed a worst profile in EOLS-CRCs either in low and high stages even though young patients were treated more often with adjuvant chemotherapy compared to older ones at the same disease stage.

CONCLUSIONS

Most EOLS-CRCs are sporadic non Lynch, microsatellite stable (MSS) CRCs. Our data show that when compared with LOLS-CRCs the early group represents an aggressive disease with worst outcome underlining a possible different carcinogenic pathway.

Efficacious fluorescence turn-on probe for high-contrast imaging of human cells overexpressing quinone reductase activity

A turn-on substrate probe is activated by an oxidoreductase, offering fluorescence images of cancer cells with unprecedented positive signal-to-negative background ratios.

Rising Incidence of Colorectal Cancer Among Young Hispanics in Texas

GOALS

To investigate trends in colorectal cancer (CRC) incidence and survival among Hispanics in Texas.

BACKGROUND

The incidence of CRC is rising among young adults in the United States. Given Texas' large Hispanic population, investigating CRC trends in Texas may provide valuable insight into the future of CRC epidemiology in an ever-diversifying US population.

STUDY

Data from the Texas Cancer Registry (1995 to 2010) were used to calculate age-adjusted CRC rates based on the 2000 US standard population. Annual percentage change (APC) and 5-year cancer-specific survival (CSS) rates were reported by age, race/ethnicity, stage, and anatomic location.

RESULTS

Of 123,083 CRC cases, 11% occurred in individuals below 50 years old, 26% of whom were Hispanic. Incidence was highest among African Americans (AAs; 76.3/100,000), followed by non-Hispanic whites (NHWs; 60.2/100,000) and Hispanics (50.8/100,000). Although overall CRC incidence declined between 1995 and 2010 (APC, -1.8%; P<0.01), trends differed by age and race/ethnicity. Among individuals 50 years and above, the rate of decline was statistically significant among NHWs (APC, -2.4%; P<0.01) and AAs (APC, -1.3%; P<0.01) but not among Hispanics (APC, -0.6%; P=0.13). In persons aged 20 to 39 years, CRC incidence rose significantly among Hispanics (APC, 2.6%; P<0.01) and NHWs (APC, 2.4%; P<0.01), but not AAs (APC, 0.3%; P=0.75). CSS rates among Hispanics and NHWs were comparable across most age groups and cancer stages, whereas CSS rates among AAs were generally inferior to those observed among NHWs and Hispanics.

CONCLUSIONS

Although CRC incidence has declined in Texas, it is rising among young Hispanics and NHWs while declining more slowly among older Hispanics than among older NHWs and AAs.

Targeting CDK6 in cancer: State of the art and new insights

Cyclin-dependent kinase 6 (CDK6) plays a vital role in regulating the progression of the cell cycle. More recently, CDK6 has also been shown to have a transcriptional role in tumor angiogenesis. Up-regulated CDK6 activity is associated with the development of several types of cancers. While CDK6 is over-expressed in cancer cells, it has a low detectable level in non-cancerous cells and CDK6-null mice develop normally, suggesting a specific oncogenic role of CDK6, and that its inhibition may represent an ideal mechanism-based and low toxic therapeutic strategy in cancer treatment. Identification of selective small molecule inhibitors of CDK6 is thus needed for drug development. Herein, we review the latest understandings of the biological regulation and oncogenic roles of CDK6. The potential clinical relevance of CDK6 inhibition, the progress in the development of small-molecule CDK6 inhibitors and the rational design of potential selective CDK6 inhibitors are also discussed.

First-line therapy in HER2 positive metastatic breast cancer: is the mosaic fully completed or are we missing additional pieces?

The discovery of human epidermal growth factor receptor 2 (HER2) and its role in the biology of breast cancer and the subsequent development of HER2-targeted therapies, have dramatically improved clinical outcomes for women with early-stage and advanced HER2-positive breast cancer (BC).

HER-2 targeted therapies represent a major step forward in achieving the goal of delivering individualized targeted therapy for BC, and trastuzumab was the first anti-HER-2 strategy to be approved for treatment of HER-2 positive BC.

This review discusses the treatment of metastatic HER2-positive BC and describes efficacy and safety of novel anti-HER2 target therapies in first-line metastatic settings and the future challenges include refining such treatments, reducing toxicity and simultaneously developing innovative therapies. Furthermore, combinations of trastuzumab and drugs targeting the downstream pathway are described.

In the next future will be possible to use an ample armamentarium of combination therapies directed against HER2 and key signaling components integrated in the HER network. This approach will allow clinicians to tailor the management of the individual patient on the basis of tumor- specific biomarker profiles.

There is an urgent need for prospective biomarker-driven trials to identify patients for whom targeting is cost-effective.

High frequency of KRAS mutation in early onset colorectal adenocarcinoma: implications for pathogenesis

While the incidence of sporadic early onset (defined here as ≤40 years of age) colorectal cancer is increasing, its molecular pathogenesis remains unclear. In particular, previous studies have suggested that the genetic initiating events in these patients may be distinct from those observed in older colorectal cancer patients. We aimed to study clinical, histopathological, and molecular features of early onset colorectal cancer. We identified 68 consecutive sporadic early onset colorectal cancer cases with available molecular data treated in our institution between 2007 and 2014. Consistent with previous reports, the majority of sporadic early onset colorectal cancer patients had left-sided tumors, which were predominantly of low histologic grade, but advanced clinical stage. A subset of tumors (<40%) contained mucinous or signet ring cell features. DNA mismatch repair pathway, commonly associated with Lynch syndrome, was abnormal only in a minor subset of cases. In contrast to the low prevalence (<30%) of KRAS mutations reported by previous studies, we found that a significantly higher proportion (54%) of early onset colorectal cancer cases harbored KRAS mutations, a finding that was independent of tumor stage. The high prevalence of KRAS mutation in early onset colorectal cancer suggests that it shares common genetic initiating events with colorectal cancer in older patients.

Inhibition of oleandrin on the proliferation show and invasion of osteosarcoma cells in vitro by suppressing Wnt/β-catenin signaling pathway

Background

Osteosarcoma (OS) is a high-grade bone sarcoma with early metastasis potential, and the clinical chemotherapy drugs that are currently used for its treatment have some limitations. Recently, several studies have reported the selective antitumor effect of oleandrin on various tumor cells. In this study, we aimed to evaluate the effects and underlying mechanisms of oleandrin on OS cells.

Methods

The effect of oleandrin on the proliferation, morphology, and apoptosis of U2OS and SaOS-2 cells were analyzed in vitro. The activity of the Wnt/β-catenin signaling pathway was determined using a dual luciferase assay. Semi-quantitative RT-PCR and western blot assays were performed to evaluate the mRNA and total protein expression of the downstream target genes. Changes of β-catenin in intracellular localization were also explored using a western blot after separating the nucleus and cytoplasm proteins. The MMP-2 and MMP-9 enzymatic activities were determined using gelatin zymography.

Results

Oleandrin significantly inhibited the proliferation and invasion of OS cells in vitro, and induced their apoptosis. After treatment with oleandrin, the TOP/FOP flash ratio in OS cells was noticeably decreased, which indicated that the Wnt/β-catenin signaling pathway was repressed. The expression of related Wnt target genes and total β-catenin was downregulated, and a reduced nuclear β-catenin level by oleandrin was observed as well. In addition, oleandrin suppressed the activities of MMP-2 and MMP-9.

Conclusions

Oleandrin, in vitro, exerted a strong antitumor effect on human OS cells by suppressing the Wnt/β-catenin signaling pathway, which interfered with the proliferation and invasion of OS cells, as well as induced cells apoptosis. Moreover, the expression and activities of MMP-2 and MMP-9 were downregulated by oleandrin, which contributed to the cells’ lower invasiveness.

Induction of active demethylation and 5hmC formation by 5-azacytidine is TET2 dependent and suggests new treatment strategies against hepatocellular carcinoma

BACKGROUND

Global deregulation of DNA methylation is one of the crucial causes of hepato cellular carcinoma (HCC). It has been reported that the anti-cancer drug 5-azacytidine (5-AZA) mediates the activation of tumor suppressor genes through passive demethylation by inhibiting DNMT1. Recent evidence suggests that active demethylation which is mediated by ten-eleven translocation (TET) proteins may also be an important step to control global methylation. However, there exists a controversial discussion in which TET proteins are involved in the demethylation process in HCC. Therefore, we firstly wanted to identify which of the TETs are involved in demethylation and later to study whether or not 5-AZA could trigger the TET-dependent active demethylation process in HCC. HCC cell lines (Huh-7, HLE, HLF), primary human hepatocytes (hHeps), and tissues from both healthy (55 patients) and HCC patients (55 patients) were included in this study; mRNA levels of isocitrate dehydrogenase (IDH1, 2) and TETs (TET1-3) were studied via qPCR and confirmed by Western blot. The expression of 5hmC/5mC was determined by immunohistochemistry in human HCC tissues and the corresponding adjacent healthy liver. HCC cell lines were stimulated with 5-AZA (0-20 μM) and viability (Resazurin conversion), toxicity (LDH release), proliferation (PCNA), and 5hmC/5mC distribution were assessed. In addition, knockdown experiments on TET proteins in HCC cell lines using short interference RNAs (siRNAs), in the presence and absence of 5-AZA, were performed.

RESULTS

Our data applying qPCR, immunofluorescence, and Western blotting clearly show that TET2 and TET3 but not TET1 were significantly decreased in HCC tissue and different HCC cell lines compared to non-tumor liver tissues and hHeps. In addition, we show here for the first time applying knockdown experiments that 5-AZA is able to trigger an active TET2-dependent demethylation process with concomitant significant changes in 5hmC/5mC in HCC cell lines and hHeps.

CONCLUSIONS

Our data clearly show that the expression and activity of TET2 and TET3 proteins but not TET1 are impaired in hepatocellular carcinoma leading to the reduction of 5hmC in HCCs. Furthermore, this study identified a novel function of 5-azacytidine in promoting a TET-mediated generation of 5hmC suggesting that the availability of 5-AZA in cancer cells will have various effects on different epigenetic targets. These findings may open new therapeutic strategies for epigenetic drugs to treat HCC.

Effect of parthenolide on growth and apoptosis regulatory genes of human cancer cell lines

CONTEXT

Parthenolide (a sesquiterpene lactone), a bioactive compound of Tanacetum parthenium (L.) Schultz Bip. (Asteraceae) herb, has been reported for antioxidant and anticancer activities.

OBJECTIVE

The present study evaluated the effect of parthenolide on growth and apoptosis-regulatory genes of human cervical cancer (SiHa) and breast cancer (MCF-7) cell lines.

MATERIALS AND METHODS

The cytotoxic activity of parthenolide (3.5-21 µM) was examined by MTT and LDH assays at 24 and 48 h time intervals. Apoptotic activity was evaluated by expression analysis of multiple apoptosis-regulatory genes (i.e., p53, Bcl-2, Bax, caspase-3, -6, and -9) by reverse transcriptase-PCR and DNA fragmentation assay.

RESULTS

Parthenolide inhibited the growth of SiHa and MCF-7 cell lines in a concentration-dependent manner at 24 and 48 h time intervals (p < 0.001). The IC50 value of parthenolide against SiHa and MCF-7 cells were 8.42 ± 0.76 and 9.54 ± 0.82 μM, respectively. Parthenolide-treated cells showed up-regulation of p53, Bax, caspase-3, -6, and -3 genes and down-regulation of Bcl-2 gene (p ≤ 0.008). At IC50, the p53 gene was up-regulated by 9.67- and 3.15-fold in SiHa and MCF-7 cells, respectively. The Bax to Bcl-2 ratio was 3.4 and 2.3 for SiHa and MCF-7 cells, respectively. Also, the fragmented genomic DNA in parthenolide-treated cells showed the signs of apoptosis.

CONCLUSION

Our study endorsed the biological activity of parthenolide and demonstrated the parthenolide-induced growth inhibition and apoptosis in SiHa and MCF-7 cells by modulating the expression of apoptosis-regulatory genes.

Early-onset colorectal cancer: a separate subset of colorectal cancer

Colorectal cancer (CRC) has a great impact on the world population. With increasing frequency, CRC is described according to the presenting phenotype, based on its molecular characteristics. Classification of CRC tumors according to their genetic and/or epigenetic alterations is not only important for establishing the molecular bases of the disease, but also for predicting patient outcomes and developing more individualized treatments. Early-onset CRC is a heterogeneous disease, with a strong familial component, although the disease is sporadic in an important proportion of cases. Different molecular alterations appear to contribute to the apparent heterogeneity of the early-onset population and subgroups can be distinguished with distinct histopathologic and familial characteristics. Moreover, compared with late-onset CRC, there are characteristics that suggest that early-onset CRC may have a different molecular basis. The purpose of this review was to analyze the current state of knowledge about early-onset CRC with respect to clinicopathologic, familial and molecular features. Together, these features make it increasingly clear that this subset of CRC may be a separate disease, although it has much in common with late-onset CRC.

Low frequency of HNPCC-associated microsatellite instability and aberrant MMR protein expression in early-onset bladder cancer

OBJECTIVES

Recently, it was shown that patients with Lynch syndrome due to an MSH2 mutation are at increased risk for the development of bladder cancer. To further this discussion, we screened the largest investigated cohort of patients with early-onset bladder cancer for microsatellite instability (MSI) and mismatch repair (MMR) deficiency to determine a possible role of Lynch syndrome in young patients with bladder cancer.

METHODS

A total of 109 cases of bladder tumors from young patients (aged <45 years) were examined for MSI (Bethesda consensus panel). Expression of MMR proteins (hMLH1, hMSH2, and hMSH6) was evaluated by immunohistochemistry using a tissue microarray. Results were compared with a series of unselected consecutive bladder tumors (n = 95).

RESULTS

Regarding the frequency of MSI high (1% vs 0%) or abnormal expression of MMR proteins (2% vs 6.5%), no significant difference between the early-onset and unselected patient group was found.

CONCLUSIONS

In young patients with bladder tumors, MSI and defects in MMR protein expression were not more frequent than in a series of consecutive bladder tumors. Most bladder tumors in young patients are not to be attributed to Lynch syndrome.

A positive family history of cancer or lifestyle factors may not explain the high incidence of early-onset colorectal cancer in India

SUMMARY 

Aim: Colorectal cancer (CRC) patients from developing countries such as India exhibit distinct clinico-pathological characteristics including an early age of onset and predominant tumor localization in the rectum. However, the reason(s) for increased occurrence among the young is not clear. Materials & methods: In the current study, we performed a comparative analysis of several epidemiological features in early and late-onset CRC patients from India including association with familial syndromes, diet and lifestyle habits. Results: Surprisingly, there was no significant association of any epidemiological variable with early-onset CRC. Conclusion: Perhaps low penetrance syndromes and/or other genetic causes may be responsible for an early age of onset among Indian CRC patients.

The mutational spectrum of Lynch syndrome in cyprus

Lynch syndrome is the most common form of hereditary colorectal cancer and is caused by germline mutations in the mismatch repair (MMR) genes MLH1, MSH2, MSH6 and PMS2. Mutation carriers have an increased lifetime risk of developing colorectal cancer as well as other extracolonic tumours. The aim of the current study was to evaluate the frequency and distribution of mutations in the MLH1, MSH2 and MSH6 genes within a cohort of Cypriot families that fulfilled the revised Bethesda guidelines. The study cohort included 77 patients who fulfilled at least one of the revised Bethesda guidelines. Mutational analysis revealed the presence of 4 pathogenic mutations, 3 in the MLH1 gene and 1 in the MSH2 gene, in 5 unrelated individuals. It is noted that out of the 4 pathogenic mutations detected, one is novel (c.1610delG in exon 14 of the MLH1) and has been detected for the first time in the Cypriot population. Overall, the pathogenic mutation detection rate in our patient cohort was 7%. This percentage is relatively low but could be explained by the fact that the sole criterion for genetic screening was compliance to the revised Bethesda guidelines. Larger numbers of Lynch syndrome families and screening of the two additional predisposition genes, PMS2 and EPCAM, are needed in order to decipher the full spectrum of mutations associated with Lynch syndrome predisposition in Cyprus.