Smad4 and epithelial-mesenchymal transition proteins in colorectal carcinoma: an immunohistochemical study.

Epithelial-mesenchymal transition (EMT) plays an important role in cancer metastasis. During EMT, tumor cells acquire the capacity to migrate and invade the stroma. Activation of the transforming growth factor-b (TGF-b) signaling pathway is of major importance for the initiation of EMT. Smad4, an essential protein of this pathway, is known to complex with multiple transcription factors (e.g. Snail-1, Slug, Twist-1), in various types of cancer, promoting the repression or activation of target genes. The role of Smad4 in colorectal cancer (CRC) is not straightforward so far. In the present study forty eight resected CRC tumor specimens were immunohistochemically examined in order to assess the expression of Smad4 and its association with E-cadherin, Snail-1, Slug, Twist-1 protein expression and with various pathological parameters. Smad4 was found to be positively correlated with Snail-1, Slug and Twist-1 expression (p < 0.001). On the other hand it was negatively correlated with the expression of E-cadherin (p < 0.001). Furthermore, lymphatic invasion could be clearly associated with Smad4 expression, a finding complying with the metastatic ability of EMT cells. In conclusion, Smad4 could be considered as a central component of EMT transition in human colorectal cancer that combines with transcriptional factors to reduce E-cadherin and alter the expression of the epithelial phenotype.

Mutation profile of KRAS and BRAF genes in patients with colorectal cancer: association with morphological and prognostic criteria.

KRAS and BRAF mutations are well-recognized molecular alterations during colorectal carcinogenesis, but there is little agreement on their effect on tumor characteristics. Therefore, we aimed to evaluate the distribution of the most common KRAS and BRAF mutations in Greek patients with colorectal cancer and their possible associations with clinical histopathological parameters. In this study, 322 and 188 colorectal carcinomas were used for the mutation analysis of KRAS (exon 2) and BRAF (exon 15) genes, respectively. The mutational status of both genes was evaluated by polymerase chain reaction and sequencing analysis. Although the overall frequency of KRAS mutations (36.6%) seemed to be similar to those reported for other populations, the rate of point mutations at codon 13 was significantly lower (12%) in Greek patients with colorectal cancer and associated with male gender (P < 0.05). Tumors with G>T codon 12 transversions and G>C transitions showed more frequent lymph node metastasis (P < 0.05, P < 0.005, respectively). The rate of KRAS mutations gradually decreased with increasing histological grade (P < 0.05), as opposed to BRAF mutations, which were strongly associated with poorly differentiated tumors (P < 0.005). Additionally, we found that the histological features of preexisting adenoma were associated with the absence of BRAF mutations, in contrast to KRAS (P < 0.05). Our data suggested that there seems to be a correlation between morphological criteria and discrete genetic pathways in colorectal carcinogenesis. Moreover, ethnic or geographic factors may have an impact on genetic background of colorectal carcinomas, and specific types of KRAS mutations may influence the metastatic potential of colorectal tumors.

Hypoxia inducible factor-1 alpha and vascular endothelial growth factor in biopsies of small cell lung carcinoma.

Neoangiogenesis has been documented in small cell lung carcinoma (SCLC). In addition, antiangiogenic therapies are being tested in clinical trials that involve SCLC. However, study of the underlying mechanisms has been performed almost exclusively in cell lines. In the current study, we immunostained 30 biopsy samples of SCLC with antibodies to hypoxia inducible factor-1 alpha (HIF-1 alpha), vascular endothelial growth factor (VEGF), vascular endothelial growth factor-receptor 1 (VEGF-R1/flt-1) and vascular endothelial growth factor-receptor 2 (VEGF-R1/flk-1). The immunoreactivity was analyzed using a bivariate Spearman correlation test and linear regression analysis. We found significant correlation between HIF-1 alpha nuclear staining and VEGF staining. Moreover HIF-1 alpha+/VEGF+ cases were associated with poor survival. We also found a positive correlation between VEGF and VEGF-R2 expression. We suggest that a HIF-1 alpha/VEGF angiogenic pathway may exist in vivo in SCLC, similar to that in non-SCLC. Our data also suggest a potential VEGF/VEGFR-2 autocrine pathway in SCLC. The inclusion of novel inhibitors to HIF-1 alpha and other factors may optimize antiangiogenic interventions in SCLC.

L1 (CAM) (CD171) in ovarian serous neoplasms.

PURPOSE OF THE INVESTIGATION: The evaluation of L1 (CAM) as a tumor progression marker and as a prognostic factor in serous ovarian tumors. METHODS: L1 (CAM) protein expression was assessed by immunohistochemistry and Western blot in serous ovarian tumors [cystadenomas (n = 20), borderline tumors (n = 14) and carcinomas (n = 47)], and was correlated with stage,grade, progression-free survival time (PFS) and overall survival. RESULTS: L1 (CAM) immunoreactivity correlated significantly with stage and grade. It increased from benign tumors to early carcinomas and to advanced stage carcinomas progressively and significantly. In Stage III G3 carcinoma patients, low L1 (CAM) expressing tumors exhibited better response to chemotherapy and were associated with statistically significantly longer PFS (p = 0.002). CONCLUSION: L1 (CAM) expression represents a novel diagnostic marker in serous ovarian neoplasms that shows characteristics of tumor progression. L1 expression was associated with chemotherapy response.

Xanthogranulomatous salpingitis: report of three cases and comparison with a case of pseudoxanthomatous salpingitis.

Xanthogranulomatous inflammation, an uncommon form of chronic inflammation, has been described in several organs including those of the female genital tract. A rare condition described as pseudoxanthomatous salpingitis or pseudoxanthomatous salpingiosis, which is often associated with endometriosis, has been distinguished from xanthogranulomatous inflammation of the fallopian tube based on its histological features. In the present report three cases of xanthogranulomatous salpingitis and one case of pseudoxanthomatous salpingitis are presented and their clinical, pathological and histochemical features are compared.