Resistance to apoptosis should not be taken as a hallmark of cancer

In the research community, resistance to apoptosis is often considered a hallmark of cancer. However, pathologists who diagnose cancer via microscope often see the opposite. Indeed, increased apoptosis and mitosis are usually observed simultaneously in cancerous lesions. Studies have shown that increased apoptosis is associated with cancer aggressiveness and poor clinical outcome. Furthermore, overexpression of Bcl-2, an antiapoptotic protein, is linked with better survival of cancer patients. Conversely, Bax, CD95, Caspase-3, and other apoptosis-inducing proteins have been found to promote carcinogenesis. This notion of the role of apoptosis in cancer is not new; cancer cells were found to be short-lived 88 years ago. Given these observations, resistance to apoptosis should not be considered a hallmark of cancer.

Key nodes of a micro RNA network associated with the integrated mesenchymal subtype of high-grade serous ovarian cancer

Metastasis is the main cause of cancer mortality. One of the initiating events of cancer metastasis of epithelial tumors is epithelial-to-mesenchymal transition(EMT), during which cells dedifferentiate from a relatively rigid cell structure/morphology to a flexible and changeable structure/morphology often associated with mesenchymal cells. The presence of EMT in human epithelial tumors is reflected by the increased expression of genes and levels of proteins that are preferentially present in mesenchymal cells. The combined presence of these genes forms the basis of mesenchymal gene signatures, which are the foundation for classifying a mesenchymal subtype of tumors. Indeed, tumor classification schemes that use clustering analysis of large genomic characterizations, like The Cancer Genome Atlas(TCGA), have defined mesenchymal subtype in a number of cancer types, such as high-grade serous ovarian cancer and glioblastoma. However, recent analyses have shown that gene expression-based classifications of mesenchymal subtypes often do not associate with poor survival. This "paradox" can be ameliorated using integrated analysis that combines multiple data types. We recently found that integrating m RNA and micro RNA(mi RNA) data revealed an integrated mesenchymal subtype that is consistently associated with poor survival in multiple cohorts of patients with serous ovarian cancer. This network consists of 8 major mi RNAs and 214 m RNAs. Among the 8 mi RNAs, 4 are known to be regulators of EMT. This review provides a summary of these 8 mi RNAs, which were associated with the integrated mesenchymal subtype of serous ovarian cancer.

Long non-coding RNA highly up-regulated in liver cancer promotes exosome secretion

BACKGROUND Highly upregulated in liver cancer (HULC) is a long non-coding RNA (lncRNA) which has recently been identified as a key regulator in hepatocellular carcinoma (HCC) progression. However, its role in the secretion of exosomes from HCC cells remains unknown. AIM To explore the mechanism by which HULC promotes the secretion of exosomes from HCC cells. METHODS Serum and liver tissue samples were collected from 30 patients with HCC who had not received chemotherapy, radiotherapy, or immunotherapy before surgery. HULC expression in serum exosomes and liver cancer tissues of patients was measured, and compared with the data obtained from healthy controls and tumor adjacent tissues. The effect of HULC upregulation in HCC cell lines and the relationship between HULC and other RNAs were studied using qPCR and dualluciferase reporter assays. Nanoparticle tracking analysis was performed to detect the quantity of exosomes.RESULTS HULC expression in serum exosomes of patients with HCC was higher than that in serum exosomes of healthy controls, and HULC levels were higher in liver cancer tissues than in tumor adjacent tissues. The expression of HULC in serum exosomes and liver cancer tissues correlated with the tumor-node-metastasis (TNM) classification, and HULC expression in tissues correlated with that in serum exosomes. Upregulation of HULC promoted HCC cell growth and invasion and repressed apoptosis. Notably, it also facilitated the secretion of exosomes from HCC cells. Moreover, qPCR assays showed that HULC repressed microRNA-372-3p (miR-372-3p) expression. We also identified Rab11a as a downstream target of miR-372-3p. Dual-luciferase reporter assays suggested that miR-372-3p could directly bind both HULC and Rab11a. CONCLUSION Our findings illustrate the importance of the HULC/miR-372-3p/Rab11a axis in HCC and provide new insights into the molecular mechanism regulating the secretion of exosomes from HCC cells.

Coexpression of MYC and BCL-2 predicts prognosis in primary gastrointestinal diffuse large B-cell lymphoma

AIM:To investigate whether MYC and BCL-2 coexpression has prognostic significance in primary gastrointestinal diffuse large B-cell lymphoma(PGI-DLBCL)patients,and explore its associations with patients’clinical parameters.METHODS:Fresh and paraffin-embedded tumor tissue samples from 60 PGI-DLBCL patients who had undergone surgery at the Tianjin Medical University Cancer Institute and Hospital from January 2005 to May 2010 were obtained,and 30 lymphoid tissue samples from reactive lymph nodes of age-and sexmatched patients represented control samples.Staging and diagnostic procedures were conducted according to the Lugano staging system.All patients had been treated with three therapeutic modalities:surgery,chemotherapy,or radiotherapy.Expression of MYC and BCL-2 were detected at both protein and m RNA levels by immunohistochemistry and real-time RT-PCR.RESULTS:Positive expression levels of MYC and BCL-2proteins were detected in 35%and 45%of patients,respectively.MYC+/BCL-2+protein was present in30%of patients.MYC and BCL-2 protein levels were correlated with high MYC and BCL-2 m RNA expression,respectively(both P<0.05).We found that advancedstage disease(atⅡE-Ⅳ)was associated with MYC and BCL-2 coexpression levels(P<0.05).In addition,MYC+/BCL-2+patients had more difficulty in achieving complete remission than others(P<0.05).Presenceof MYC protein expression only affected overall survivaland progression-free survival(PFS)when BCL-2 proteinwas coexpressed.The adverse prognostic impact ofMYC+/BCL-2+protein on PFS remained significant(P<0.05)even after adjusting for age,Lugano stage,international prognostic index,and BCL-2 proteinexpression in a multivariable model.CONCLUSION:MYC+/BCL-2+patients have worsechemotherapy response and poorer prognosis thanpatients who only express one of the two proteins,suggesting that assessment of MYC and BCL-2 expressionby immunohistochemistry has clinical significance inpredicting clinical outcomes of PGI-DLBCL patients.

Autophagy Enhances the Aggressiveness of Human Colorectal Cancer Cells and Their Ability to Adapt to Apoptotic Stimulus

Objective To investigate LC3B-Ⅱand active caspase-3 expression in human colorectal cancer to elucidate the role of autophagy and to explore the relationship of autophagy with apoptosis in human colorectal cancer. Methods LC3B expression was detected by immunohistochemistry in 53 human colorectal cancer tissues and 20 normal colon tissues.The protein levels of LC3B-Ⅱand active caspase-3 were also determined by Western blot analysis in 23 human colorectal cancer tissues and 10 normal colon tissues. Results LC3B was expressed both in cancer cells and normal epithelial cells.LC3B expression in the peripheral area of cancer tissues was correlated with several clinicopathological factors,including tumor differentiation(P=0.002),growth pattern of the tumor margin (P=0.028),pN(P=0.002),pStage(P=0.032),as well as vessel and nerve plexus invasion(P=0.002).The protein level of LC3B-Ⅱin cancer tissue was significantly higher than in normal tissue(P=0.038),but the expression of active forms of procaspase-3 in cancer tissue was lower(P=0.041).There was a statistically significant positive correlation between the expression levels of LC3B-Ⅱand the active forms of procaspase-3(r=0.537,P=0.008). Conclusions Autophagy has a prosurvival role in human colorectal cancer.Autophagy enhances the aggressiveness of colorectal cancer cells and their ability to adapt to apoptotic stimulus.

MicroRNA-506 is up-regulated in the development of pancreatic ductal adenocarcinoma and is associated with attenuated disease progression

Background: MicroRNA?506(miR?506) has been reported to function in several tumors as a tumor suppressor gene or oncogene. However, the expression and role of miR?506 in pancreatic ductal adenocarcinoma(PDAC) remains unclear. In this study, we aimed to evaluate the phenotype of miR?506 in PDAC.Methods: Using mi RNA in situ hybridization, we examined the expression of miR?506 in 113 PDACs and 87 paired normal pancreatic tissues. We evaluated mi R?506 expression in PDAC cells, normal pancreatic ducts, and acinus/islands, and we analyzed the associations between miR?506 expression and the clinicopathologic characteristics of PDAC patients.Results: miR?506 expression was higher in PDAC than in matched normal pancreatic ductal cells(P < 0.001). On the other hand, the combined group of well and moderately diferentiated PDACs showed higher levels of mi R?506 than the poorly diferentiated ones(P = 0.023). Moreover, mi R?506 expression was negatively associated with pathologic T category(P = 0.004) and lymph node metastasis(P = 0.033), suggesting that mi R?506 might inhibit the progression of PDAC.Conclusions: Our results suggest that mi R?506 either plays a role as an oncogene in the tumorigenesis and a tumor suppressor in the progression or serves as a house?keeping, tumor?suppressing mi RNA, whose expression can be activated by oncogenic signals in early development to hinder the progression of PDAC.

Expression of Coxsackievirus and Adenovirus Receptor in Human Lung Cancer： Possible Clinical Significance

OBJECTIVE To explore the relationship between CAR and the development of human lung cancer, as well as to provide the basis for the clinical treatment of lung cancer using an adenovirus vector-based gene therapy. METHODS CAR expression was assessed immunohisto- chemically in tumoral, paraneoplastic and normal samples from 112 lung cancer patients. At the same time, the mRNA and protein expression of CAR in 32 cases were determined by RT-PCR and Western blot. The relationship between CAR expression and clinicopathologic parameters was statistically analyzed. RESULTS There was no expression of CAR in normal lung tissue but a little in paraneoplastic tissue. The positive rate was 43% in squamous cell carcinoma, and 70% in adenocarcinoma. Both were much significantly higher than that in paraneoplastic tissue. The CAR expression level in adenocarcinoma was higher than that in squamous cell cancer, mRNA expression by RT-PCR and protein expression by Western blot were consistent with immunohistochemistry results. CONCLUSION CAR is overexpressed in human lung cancer, especially in adenocarcinoma. This data offer the reliable basis for adenovirus-mediated gene therapy of lung cancer; more important, CAR may take part in the formation or development of lung cancer; this may be exploitable for the development of antibody-directed therapy in human lung cancer.