The clinical significance of p53, p21, and p27 expressions in rectal carcinoma

The Prognostic Significance of c-Met and p53 Immunohistochemical Expression in Gastric and Colorectal Carcinomas

BACKGROUND: Colorectal and gastric carcinomas are the most common and deadly gastrointestinal (GIT) malignancies. AIM: This study aimed to evaluate the expression of c-Met and p53 in gastric and colorectal carcinomas (CRCs) as well as colorectal adenomas using immunohistochemistry. MATERIALS AND METHODS: c-Met and p53 immunohistochemical expression was conducted on 66 cases of gastric adenocarcinomas and total of 60 colonic cases (36 CRCs and 24 colorectal adenomas). RESULTS: In this study, c-Met was positively expressed in 54.5% of gastric carcinomas and 50% of CRCs. In addition, p53 was positively expressed in 56.1% of gastric carcinomas and 72.2% of CRCs. Moreover, higher expression of both c-Met (p = 0.001) and p53 expression (p < 0.001) was reported in CRCs compared to colorectal adenomas. In the same context, c-Met and p53 expressions were positively correlated with intestinal type gastric adenocarcinoma (p < 0.001 and p = 0.03, respectively). Moreover, c-Met was correlated with non-mucinous adenocarcinomas (p = 0.008) and lower grades (p < 0.001) of gastric carcinomas. As regard survival analysis in gastric carcinomas, median overall survival (OS) was better in p53 positive patients (p = 0.05), patients with negative lymph node metastasis (p = 0.03), and patients with better response to neoadjuvant chemotherapy (p = 0.04). In contrast, c-Met did not exhibit significant correlation with OS (p > 0.05). Both c-Met and p53 did not reveal significant correlation with tumor stage and site in both CRCs and gastric carcinomas (p > 0.05). CONCLUSION: We concluded that c-Met and p53 are expressed in the most common GIT malignancies addressing them as potential biomarkers. In addition, c- Met and p53 may have a potential role in colorectal cancer development as they showed higher positivity in CRCs compared to adenomas.

The prognostic significance of protein arginine methyltransferase 6 expression in colon cancer

Protein arginine methylation is involved in cellular differentiation and proliferation. Recently, aberrant expression of protein arginine methyltransferases, which are responsible for the methylation reaction, has been reported in various types of cancer. However, there is no clear evidence regarding the prognostic value of abnormal PRMT6 expression in colorectal cancer or the effect of PRMT6 regulation on CRC cells. We investigated the expression patterns of PRMT6 in patients with stage II and III CRC. We detected nuclear expression of PRMT6 in 23.7% of carcinoma samples by immunohistochemistry. Among the clinicopathological parameters, the ratio of poorly differentiated cancer cells was approximately two-fold higher in patients with PRMT6-positive disease than in those with PRMT6-negative disease (p = 0.002). Patients with PRMT6-positive CRC had a shorter disease-free survival than those with PRMT6-negative CRC in both univariate and multivariate analyses (p = 0.018 and p = 0.035, respectively). siRNA-mediated inhibition of PRMT6 expression in CRC cells induced p21^WAF1/CIP1 overexpression and suppressed cell growth and colony-forming ability. Concomitantly, apoptosis was induced in PRMT6-suppressed CRC cells. These data suggest that PRMT6 can serve as a biomarker for unfavorable prognosis and as a therapeutic target in CRC.

Nuclear Factor Kappa B, Matrix Metalloproteinase-1, p53, and Ki-67 Expressions in the Primary Tumors and the Lymph Node Metastases of Colorectal Cancer Cases

Colorectal cancer (CRC) is the third most frequent malignancy. Many factors such as NF-κB, matrix metalloproteinase-1 (MMP-1), p53, and Ki-67 are likely to be involved in its development and progression. Lymph node metastases indicate increased tumor burden and tumor cell heterogeneity and affect both the treatment strategies and the prognosis. In this study, expressions of NF-κB, MMP-1, p53, and Ki-67 were between the primary tumors and lymph node metastases in 110 Dukes' stage C, CRC cases by immunohistochemical methods, related to patients' clinical outcomes. NF-κB, p53, and Ki-67 expressions were significantly higher in the metastatic lymph nodes compared to the primary tumor tissues (P = 0.04, P = 0.04, and P = 0.01, resp.). In the metastatic lymph nodes NF-κB expression was correlated with both p53 (r = 0.546, P = 0.003) and Ki-67 (r = 0.586, P = 0.0001) expressions. The univariant and multivariant analyses showed that only “pT stage” preserved an independent prognostic significance for recurrence-free survival rates and 5-year overall survival rates (P < 0.001 for both). Metastatic cells can acquire different biological characteristics compared to their primaries. Elucidation of properties acquired by metastatic cells is important in order to better determine prognosis, reverse drug resistance, and discover new treatment alternatives.

Apparent Diffusion Coefficient (ADC) value: a potential imaging biomarker that reflects the biological features of rectal cancer

Objective

We elected to analyze the correlation between the pre-treatment apparent diffusion coefficient (ADC) and the clinical, histological, and immunohistochemical status of rectal cancers.

Materials and Methods

Forty-nine rectal cancer patients who received surgical resection without neoadjuvant therapy were selected that underwent primary MRI and diffusion-weighted imaging (DWI). Tumor ADC values were determined and analyzed to identify any correlations between these values and pre-treatment CEA or CA19-9 levels, and/or the histological and immunohistochemical properties of the tumor.

Results

Inter-observer agreement of confidence levels from two separate observers was suitable for ADC measurement (k  =  0.775). The pre-treatment ADC values of different T stage tumors were not equal (p  =  0.003). The overall trend was that higher T stage values correlated with lower ADC values. ADC values were also significantly lower for the following conditions: tumors with the presence of extranodal tumor deposits (p  =  0.006) and tumors with CA19-9 levels ≥ 35 g/ml (p  =  0.006). There was a negative correlation between Ki-67 LI and the ADC value (r  =  −0.318, p  =  0.026) and between the AgNOR count and the ADC value (r  =  −0.310, p  =  0.030).

Conclusion

Significant correlations were found between the pre-treatment ADC values and T stage, extranodal tumor deposits, CA19-9 levels, Ki-67 LI, and AgNOR counts in our study. Lower ADC values were associated with more aggressive tumor behavior. Therefore, the ADC value may represent a useful biomarker for assessing the biological features and possible relationship to the status of identified rectal cancers.

The prognostic value of the apoptosis pathway in colorectal cancer: a review of the literature on biomarkers identified by immunohistochemistry

Research towards biomarkers that predict patient outcome in colorectal cancer (CRC) is rapidly expanding. However, none of these biomarkers have been recommended by the American Association of Clinical Oncology or the European Group on Tumor Markers. Current staging criteria result in substantial under-and over-treatment of CRC patients. Evasion of apoptosis, a characteristic feature of tumorigenesis, is known to correlate with patient outcome. We reviewed the literature on immunohistochemistry-based studies between 1998 and 2011 describing biomarkers in this pathway in CRC and identified 26 markers. Most frequently described were p53, Bcl-2, survivin, and the Fas and TRAILR1 receptors and their ligands. None of the studies reviewed provided sufficient support for implementing a single marker into current clinical practice. This is likely due to the complex biology of this pathway. We suggest focusing on the combination of key markers within the apoptosis pathway that together represent an ‘apoptotic tumor profile’, which better reflects the status of this pathway in a tumor.

Rectal cancer and importance of chemoradiation in the treatment

Neoadjuvant chemoradiation is used as a preoperative standard treatment for the majority of patients with Stage II/III rectal cancers and, in attempt to facilitate surgical intervention, reduce the rate of local recurrence and improve overall outcomes in patients suffering from this malignancy. However, this modality results in a wide range of clinical responses. In many cases, a pathological complete response is achieved, while in others, receiving the same form of treatment, the tumor continues to grow. The specific phenotype of the tumor plays a major role in rendering tumor cells a survival advantage to the cytotoxic effects of chemoradiation. Several factors participating in proliferation, cell cycle, apoptosis and hypoxiahave been investigated under a variety of conditions in pre-irradiated tissues and post-irradiated tumors. Mutations in the genes of these pathways have shown to lead to resistance to chemoradiation. This chapter describes colon cancer with emphasis on the molecular mechanisms that may lead to chemoradio-resistance of cells with cytotoxically induced DNA injury in rectal cancer.

Survivin Expression in Non–small-cell Lung Carcinomas: Correlation With Apoptosis and Other Apoptosis-related Proteins, Clinicopathologic Prognostic Factors and Prognosis

The role of survivin that regulates the biological behavior of non-small-cell lung carcinoma (NSCLC) is still controversial. We aimed to investigate survivin expression in NSCLC and to define any correlation with expressions of p53, bcl-2, bax, apoptotic index (AI), tumor cell proliferation, clinicopathologic variables, and overall survival. Tumors of 63 patients with NSCLC were examined for expressions of survivin, p53, bcl-2, bax, and Ki-67 by immunohistochemistry. AI was also evaluated. Results for each antibody were correlated with each other, and with clinicopathologic variables including age, sex, histologic subtype, TNM (T: primary tumor, N: regional lymph node metastasis, M: distant metastasis) stage, lymph node status, smoking history, and prognosis. Nuclear survivin expression was inversely correlated with p53 expression (P = 0.04, r = - 0.367), and tumor stage (P = 0.03, r = - 0.273), and positively correlated with tumor cell proliferation (P = 0.009, r = 0.329). Cytoplasmic survivin expression positively correlated with smoking history (P = 0.02, r = 0.282). Survivin/bax ratio was inversely correlated with AI (r: - 0.004). By Kaplan-Meier analysis, TNM stage (P < or = 0.001), lymph node metastasis (P = 0.04), and Ki-67 index (P < or = 0.001) were associated with survival, whereas survivin was not. In multivariate analysis, only TNM stage was an independent predictor. Although survivin and other apoptosis-related protein expressions fail to predict the clinical outcome, the present findings suggest that survivin is involved in tumor cell apoptosis and proliferation and may play a role in critical steps of cancer progression in NSCLC.