Interpretation of P16 expression as a marker of HPV in colorectal cancer.

BACKGROUND: Colorectal cancer is one of the most prevalent types of tumors worldwide. P16ᴵᴺᴷ4ᵃ is a widely used immunohistochemical marker for high-risk HPV infection. The purpose of this study is to explore the relationship between P16 expression as an indicator of HPV infection and colorectal cancer in Egyptian patients, as well as its association with histopathological characteristics. MATERIAL AND METHODS: The study was performed on 59 cases of colorectal carcinoma cases and 30 specimens of normal colonic mucosa. RESULTS: p16 protein was detected in 22% (13 of 59) of patients with colorectal carcinoma. No evidence of P16 expression in all 30 cases of non-neoplastic colonic mucosa was found. More frequent expression of P16 was seen in distal carcinomas. CONCLUSION: our study demonstrated that P16 protein is expressed in a reasonable percent of colorectal carcinoma cases, suggesting a role of HPV in colorectal carcinogenesis. The present study highlights the role of p16 protein expression which is important in the pathogenesis in colorectal carcinoma, especially regarding distal tumors.

Evaluation of EZH2 and ERRα in colorectal carcinoma: an immunohistochemical study.

The combined immunohistochemical evaluation of EZH2 (enhancer of zeste homolog 2) and ERRα (estrogen-related receptor α), in relation to clinicopathological prognostic factors and patients' outcome, has not been performed yet in colorectal carcinoma (CRC). In order to achieve this aim, 120 samples were extracted; 60 cases of CRC; and 60 samples from normal colonic tissue. Our study showed that 63.3% and 38.3% of CRC cases reveal high EZH2 and high ERRα nuclear expression, respectively. 6.6% and 8.3% of normal colonic mucosa samples express low EZH2 and low ERRα nuclear expression, respectively. High EZH2 and high ERRα expression correlate with late tumor stages (p = 0.001 each), high grade (p = 0.001, p = 0.009 respectively), positive lymph node involvement (p = 0.001, p = 0.002 respectively) and larger tumor size (p = 0.001 each). There is a moderate highly statistically significant agreement (κ = 0.467, p = 0.001) between EZH2 and ERRα immunohistochemical expression. By Kaplan Meier analysis, high EZH2 and high ERRα show statistically significant shorter overall survival, and progression free survival than cases with low EZH2 and low ERRα immunohistochemical expression, respectively. Thus, EZH2 and ERRα might serve as potential promising prognostic markers in CRC.

Natural killer NKG2A and NKG2D in patients with colorectal cancer.

BACKGROUND: Natural-killer group 2 (NKG2), a characteristic receptor of natural killer (NK) cell family, assumes a vital role in modulating NK cytotoxic function. We aimed to detect mRNA expression of both NKG2A and NKG2D in serum NK cells obtained from colorectal cancer (CRC) patients. METHODS: We enrolled 36 patients with newly diagnosed CRC, as well as 15 group matched healthy individuals. The patients were further classified into: 23 non-metastatic CRC (group 1) and 13 metastatic CRC (group 2). We detected the expression of NKG2A and NKG2D serum levels for all participants utilizing real-time polymerase chain reaction (RT-PCR). RESULTS: NKG2D and NKG2A mRNA levels in peripheral blood mononuclear cells (PBMCs) were significantly elevated in patients with CRC compared to controls (P<0.01). NKG2D or NKG2A showed sensitivity (77.8, 83.33%) and specificity (73.33, 100%) respectively using receiver-operating characteristic (ROC) curve analysis for discrimination between patients and controls, whereas group 1 and group 2 showed no statistical significant difference in NKG2D and NKG2A levels (P>0.05). CONCLUSIONS: Our work is one of the first research that could detect an increase in NKG2D in CRC. In spite of their defensive role in tumor immune surveillance, NKG2D and NKG2A and their ligands could have misused as tumor survival tool, empowering immune avoidance and suppression.