Clinical implication of the BRAFV600E mutation in papillary thyroid carcinoma

Background: The BRAFV600E mutation is the most common genetic alteration in papillary thyroid carcinoma (PTC). In recent studies, the BRAFV600E mutation has been associated with poor clinicopathological characteristics, such as lymph node metastasis, extrathyroidal extension, and advanced stage. However, other studies have failed to establish an association between the BRAFV600E mutation and clinicopathological features. Therefore, we investigated the relationship between the BRAFV600E mutation and its clinicopathological factors at a single institution. Methods: A total of 327 consecutive patients with PTC were enrolled in this study and underwent thyroid surgery at Yeouido St. Mary's Hospital between February 2010 and December 2011.BRAFV600E mutation analysis was performed using polymerase chain reaction (PCR)-based amplification of DNA extracted from paraffin-embedded tumour specimens. Results: The BRAFV600E mutation was detected in the tumours of 241 (73.7%) patients. Lymph node metastasis, TNM stage, and multifocality were not significantly associated with the BRAFV600E mutation. However, larger tumour size, extrathyroidal extension, histologic type (classic type), and concurrent Hashimoto's thyroiditis were associated with the BRAFV600E mutation in the univariate analysis, although no clinicopathological features were associated with the BRAFV600E mutation in the multivariate analysis. Conclusion: There was no idependent prognostic factor associated with BRAFV600E mutation status in this study. The BRAFV600E mutation is unlikely to serve as a prognostic factor for PTC.

via World Journal of Surgical Oncology

Differences in risk factors between patterns of recurrence in patients after curative resection for advanced gastric carcinoma

Background: Recurrence patterns in patients who have undergone curative gastrectomy for advanced gastric carcinoma can be classified as peritoneal, hematogenous, or lymphatic. The aim of this study was to clarify differences in risk factors between these different types of recurrence pattern. Methods: Postoperative courses, including sites of recurrence and periods between surgery and recurrence, of patients who had undergone curative gastrectomy for advanced gastric carcinoma (more than pT2 invasion) were surveyed in detail. Clinicopathological factors were examined as potential independent risk factors for each recurrence pattern, based on recurrence-free survival, using multivariate analysis. Results: Multivariate analysis identified depth of tumor invasion (pT4 vs. pT2/3; hazard ratio (HR), 7.05; P < 0.001), number of lymph node metastases (pN2/3 vs. pN0/1; HR, 4.02; P = 0.001), and histological differentiation (G3/4 vs. G1/2; HR, 2.22; P = 0.041) as independent risk factors for peritoneal metastasis. The number of lymph node metastases (HR, 26.21; P < 0.001) and venous vessel invasion (HR, 5.09; P = 0.001) were identified as independent risk factors for hematogenous metastasis. The number of lymph node metastases (HR, 6.00; P = 0.007) and depth of tumor invasion (HR, 4.70; P = 0.023) were identified as independent risk factors for lymphatic metastasis. Conclusions: This study clarified differences in risk factors between various patterns of recurrence. Careful examination of risk factors could help prevent oversight of recurrences and improve detection of recurrences during follow-up. The number of lymph node metastases represents an independent risk factor for all three patterns of recurrence; thus, patients with multiple lymph node metastases warrant particular attention.

via World Journal of Surgical Oncology

Validation of suitable endogenous control genes for quantitative PCR analysis of microRNA gene expression in a rat model of endometrial cancer

Background: MicroRNAs are small RNA molecules that negatively regulate gene expression by translational inhibition or mRNA cleavage. The discovery that abnormal expression of particular miRNAs contributes to human disease, including cancer, has spurred growing interest in analysing expression profiles of these molecules. Quantitative polymerase chain reaction is frequently used for quantification of miRNA expression due to its sensitivity and specificity. To minimize experimental error in this system an appropriate endogenous control gene must be chosen. An ideal endogenous control gene should be expressed at a constant level across all samples and its expression stability should be unaffected by the experimental procedure. Results: The expression and validation of candidate control genes (4.5S RNA(H) A, Y1, 4.5S RNA(H) B, snoRNA, U87 and U6) was examined in 21 rat cell lines to establish the most suitable endogenous control for miRNA analysis in a rat model of cancer. The stability of these genes was analysed using geNorm and NormFinder algorithms. U87 and snoRNA were identified as the most stable control genes, while Y1 was least stable. Conclusion: This study identified the control gene that is most suitable for normalizing the miRNA expression data in rat. That reference gene will be useful when miRNAs expression are analyzed in order to find new miRNA markers for endometrial cancer in rat.

via Cancer Cell International

Novel agents for chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a heterogeneous group of B-cell neoplasm. CLL is typically sensitive to a variety of cytotoxic agents, but relapse frequently occurs with conventional approaches. The treatment of CLL is evolving rapidly with the introduction of novel drugs, such as bendamustine, ofatumumab, lenalidomide, ibrutinib, idelalisib, veltuzumab, XmAb5574, navitoclax, dasatinib, alvespimycin, and TRU-016. This review summarizes the most current clinical experiences with these agents in the treatment of CLL.

via Journal of Hematology & Oncology

CpG island hypermethylation-associated silencing of microRNAs promotes human endometrial cancer

Background: Endometrial cancer (EC) is the most common gynecologic malignancy, but the molecular events involved in the development and progression of EC remain unclear. This study aimed to explore epigenetic modification of genes and miRNAs involved in EC development. Methods: Ishikawa and AN3CA cells were treated with 5'-Aza-2-deoxycytidine or histone deacetylase inhibitor. The expression of miRNAs and related genes were detected by PCR and Western blot. Promoter methylation was detected by bisulfite specific PCR sequencing. The proliferation, colony formation, cell cycle progression, migration and invasion of EC cells were evaluated by MTT, soft agar assay, flow cytometry, wound healing and invasion assay, respectively. Results: Aberrant expression of miRNAs including miR-200b, miR130a/b, miR-625 and miR-222 was associated with tumorigenesis and metastasis in endometrial cancer. Silencing of miR-130b induced E-cadherin expression, while ectopic expression of miR-130b and knockdown of DICER1 increased the expression of Vimentin, zeb2, N-cadherin, Twist and Snail in EC cells. Furthermore, 5'-Aza-2-deoxycytidine and Histone deacetylase (HDAC) inhibitor inhibited the proliferation, colony formation, migration and invasion of EC cells, accompanied by reduced MMP secretion. Conclusions: Our study provides the first description of epigenetic modification of epithelial mesenchymal transition associated genes and miRNAs in EC cells, which are extensively involved in the regulation of gene expression and subsequent accumulation of malignant features of EC cells.

via Cancer Cell International

Expression patterns of Phf5a/PHF5A and Gja1/GJA1 in rat and human endometrial cancer

Endometrial adenocarcinoma is the most frequently diagnosed cancer of the female genital tract in the western world. Studies of complex diseases can be difficult to perform on human tumor samples due to the high genetic heterogeneity in human. The use of rat models is preferable since rat has similarities in pathogenesis and histopathological properties to that of human.A genomic region including the highly conserved Phf5a gene associated to development of EAC has previously been identified in an association study. PHF5A has been suggested to acts as a transcription factor or cofactor in the up regulation of expression of Gja1 gene in the presence of estrogen. It has earlier been shown that the Phf5a gene is down regulated in rat EAC derived cell lines by means of expression microarrays.We analyzed the expression of Phf5a and Gja1 by qPCR, and potential relations between the two genes in EAC tumors and non-malignant cell lines derived from the BDII rat model. In addition, the expression pattern of these genes was compared in rat and human EAC tumor samples.Changes in expression for Phf5a/PHF5A were found in tumors from both rat and human even though the observed pattern was not completely consistent between the two species. By separating rat EAC cell lines according to the genetic background, a significant lower expression of Phf5a in one of the two cross backgrounds was revealed, but not for the other. In contrast to other studies, Phf5a/PHF5A regulation of Gja1/GJA1 was not revealed in this study.

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Caspase-2 is involved in cell death induction by taxanes in breast cancer cells

Background: We studied the role of caspase-2 in apoptosis induction by taxanes (paclitaxel, novel taxane SB-T-1216) in breast cancer cells using SK-BR-3 (nonfunctional p53, functional caspase-3) and MCF-7 (functional p53, nonfunctional caspase-3) cell lines. Results: Both taxanes induced apoptosis in SK-BR-3 as well as MCF-7 cells. Caspase-2 activity in SK-BR-3 cells increased approximately 15-fold within 48 h after the application of both taxanes at the death-inducing concentration (100 nM). In MCF-7 cells, caspase-2 activity increased approximately 11-fold within 60 h after the application of taxanes (300 nM). Caspase-2 activation was confirmed by decreasing levels of procaspase-2, increasing levels of cleaved caspase-2 and the cleavage of caspase-2 substrate golgin-160. The inhibition of caspase-2 expression using siRNA increased the number of surviving cells more than 2-fold in MCF-7 cells, and at least 4-fold in SK-BR-3 cells, 96 h after the application of death-inducing concentration of taxanes. The inhibition of caspase-2 expression also resulted in decreased cleavage of initiator caspases (caspase-8, caspase-9) as well as executioner caspases (caspase-3, caspase-7) in both cell lines after the application of taxanes. In control cells, caspase-2 seemed to be mainly localized in the nucleus. After the application of taxanes, it was released from the nucleus to the cytosol, due to the long-term disintegration of the nuclear envelope, in both cell lines. Taxane application led to some formation of PIDDosome complex in both cell lines within 24 h after the application. After taxane application, p21WAF1/CIP1 expression was only induced in MCF-7 cells with functional p53. However, taxane application did not result in a significant increase of PIDD expression in either SK-BR-3 or MCF-7 cells. The inhibition of RAIDD expression using siRNA did not affect the number of surviving SK-BR-3 and MCF-7 cells after taxane application at all. Conclusion: Caspase-2 is required, at least partially, for apoptosis induction by taxanes in tested breast cancer cells. We suggest that caspase-2 plays the role of an apical caspase in these cells. Caspase-2 seems to be activated via other mechanism than PIDDosome formation. It follows the release of caspase-2 from the nucleus to the cytosol.

via Cancer Cell International