CD133 is a membrane molecule that has been, controversially, reported as a CSC marker in colorectal cancer (CRC). In this study, we sought to clarify the expression and role of CD133 in CRC. Initially the size of the CD133−expressing (CD133+) population in eight well-described CRC cell lines was measured by flow cytometry and was found to range from 0% to >95%. The cell line HT29 has a CD133+ population of >95% and was chosen for functional evaluation of CD133 after gene knockdown by RNA interference. A time course assay showed that CD133 inhibition had no significant effect on cell proliferation or apoptosis. However, CD133 knockdown did result in greater susceptibility to staurosporine-induced apoptosis (p = 0.01) and reduction in cell motility (p<0.04). Since gene knockdown may cause “off-target” effects, the cell line SW480 (which has a CD133+ population of 40%) was sorted into pure CD133+ and CD133− populations to allow functional comparison of isogenic populations separated only by CD133 expression. In concordance with the knockdown experiments, a time course assay showed no significant proliferative differences between the CD133+/CD133− populations. Also greater resistance to staurosporine-induced apoptosis (p = 0.008), greater cell motility (p = 0.03) and greater colony forming efficiency was seen in the CD133+ population than the CD133− population in both 2D and 3D culture (p<0.0001 and p<0.003 respectively). Finally, the plasticity of CD133 expression in tumour cells was tested. Quantitative PCR analysis showed there was transcriptional repression in the CD133− population of SW480. Prolonged culture of a pure CD133− population resulted in re-emergence of CD133+ cells. We conclude that CD133 expression in CRCs is associated with some features attributable to stemness and that there is plasticity of CD133 expression. Further studies are necessary to delineate the mechanistic basis of these features.

Amplification of HER-2 gene and overexpression of HER-2 receptor play a significant role in the progression of a number of malignancies such as breast cancer. Trastuzumab (anti-HER-2 therapeutic agent) has been used successfully in treatment of breast cancer. The aim of this study was to assess the pattern of HER-2 gene amplification and of HER-2 receptor expression in a spectrum of serous and mucinous ovarian tumors to determine whether HER-2 is altered in these neoplasms similar to that occurring in breast cancer. Formalin-fixed paraffin-embedded microarray tissue sections from 212 specimens were stained with HER-2 antibody using immunohistochemistry and with anti-HER-2 DNA probe using chromogenic in situ hybridization. Specimens consisted of 65 benign tumors (50 serous and 15 mucinous), 26 borderline (13 serous and 13 mucinous), 73 malignant tumors (53 serous carcinoma and 20 mucinous carcinoma), 18 metastatic deposits (13 serous and 5 mucinous), in addition to 30 normal tissues (16 ovarian surface and 14 normal fallopian tube). HER-2 protein-positive expression was not detected in the normal or the benign tissues. Borderline neoplasms showed positive staining, but no overexpression. HER-2 overexpression was seen only in 4 carcinoma specimens: 1/53 (1.8%) primary serous carcinomas and 3/20 (15%) primary mucinous carcinomas. HER-2 gene amplification was seen in 4 specimens: 2 primary mucinous carcinomas and 2 malignant deposits of these 2 mucinous carcinomas. In conclusion, alteration of HER-2 was not detected in ovarian serous neoplasms; however, in mucinous carcinoma, HER-2 amplification and overexpression occur.

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Background and aim: CD10 is expressed in urothelial carcinoma cells and cancer associated fibroblasts (CAF). In the current study, CD10 immunohistochemical staining (IHC) and CD10 mRNA expression in urothelial carcinoma of bladder (UCB) were assessed, and its relationship with tumor progression and prognosis was investigated. Patients and Methods: In this study, 106 formalin fixed paraffin-embedded (FFPE) tissue of UCB, obtained through radical cystectomy specimen, and 10 matched normal tissue samples were included.CD10 expression was evaluated by immunohistochemistry and real time PCR techniques. Results: CD10 expression in tumor cells and associated stromal fibroblasts was significantly associated with high tumor grade and advanced stage. Significant correlation was found between CD10 tumor expression and lymphovascular invasion (LVI) (P<0.001) as well as perineural invasion (PNI). CD10 expression in stromal fibroblasts was significantly associated with squamous differentiation of tumor cells, lymph node metastasis (LNM), and tumor necrosis. Positive CD10 expression in both tumor cells and associated stromal fibroblasts was associated with shorter OS . CD10 mRNA was overexpressed in tumors in comparison with the matched normal tissues. CD10 mRNA was significantly higher in invasive tumor, advanced stage tumor, and high grade tumor. There was significant correlation between CD10 mRNA tumor expression and LVI, PNI, and tumor recurrence. Conclusion: Increased expression of CD10 in the tumor and CAF was strongly correlated with tumor progression, invasion, metastasis, shorter OS, and RFS in urothelial carcinoma patients. CD10 mRNA showed significantly higher expression in tumor tissue than in matched normal tissue. CD10 mRNA was associated with depth of invasion, TNM stage, tumor grade, vascular tumor invasion, and tumor recurrence.

Introduction: This study investigated the incidence, surgical management and outcome of Gastrointestinal Stromal Tumors (GIST) in Upper Egypt. Methods: A retrospective review of all GIST patients admitted a South Egypt Cancer Institute between Jan. 2010 and Dec. 2015 was conducted. Patients' demographics, clinical presentation, tumor characteristics, radiological, pathological and immunohistochemical findings, surgical procedures, recurrence and mortality were recorded. Results: A total of 36 GIST patients were identified, stomach was the most common site (27.8%) followed by the small intestine (19.4%) and the large intestine (16.7%). The mean age at time of diagnosis as 52.8 ± 14.4 (ranged from 17 to 76 years). Of these 36 cases, 20 (55.6%) cases were males and 16 (44.4%) cases were females with a ratio of 1.2:1. About 22 cases (61.1%) presented with primary tumors, eight cases (22.2%) had primary tumors and metastases, three cases (8.35) presented with recurrent mass, whereas one case (2.2%) presented either with recurrent mass and metastases or metastases only. The majority of cases (22) had tumorsize >5 cm. Patients were stratified as high, intermediate, low and very low risk (50.6%, 30.6%, 11.1% and 2.8%, respectively). Almost all the cases were surgically managed and 75% were completely resectable. During follow up (average 26.5 months), 22 patients showed complete recovery, 7 had recurrent or metastatic disease and 2 died due to liver metastasis. Conclusion: The incidence of GIST in Upper Egypt is apparently low. Surgical resection is the preferred choice of treatment. The demographic data of GIST patients in South Egypt Cancer institute were similar to those published in the literature. Other prospective studies are required to assess the prognosis and the effect of treatment.

Objective: This study aimed to investigate the immunohistochemical expression of c-Myc in muscle invasive urothelial carcinoma (MIUC) of the urinary bladder and to evaluate the correlation of c-Myc expression with different clinicopathological parameters and outcome, including a relatively new histopathological tumor characteristic that is the growth pattern of tumor invasion. Methods: A total of 66 formalin-fixed and paraffin-embedded sections of MIUC obtained from radical cystectomy specimens were enrolled. The sections were stained with c-Myc antibody using immunohistochemistry technique. Results: Tumor cells showed variability in nuclear c-Myc expression according to the growth pattern of invasion. The median H-score of nuclear expression of infiltrative pattern was significantly higher than that of non-infiltrative pattern (p<0.001). Nuclear expression of c-Myc in tumor tissue had a significant association with poor prognostic factors (sarcomatoid variant (p<0.001), perineural invasion (p=0.037), lymphovascular invasion (p<0.001), lymph node metastasis (p<0.001), distant metastasis (p=0.042) and advanced stage grouping (p=0.001). Kaplan Meier survival analysis demonstrated that c-Myc expression could not be significantly correlated with overall survival or disease free survival rates. Conclusion: Nuclear c-Myc seems to have a prominent role in epithelial to mesenchymal transition with consequential in tumor progression and metastasis, while it is not as much useful to predict the clinical behavior of patients with MIUC.

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