Expression of c-kit and p53 in non-small cell lung cancers

Clinical and Prognostic Significance of CD117 in Non-Small Cell Lung Cancer: A Systemic Meta-Analysis

The aim of this study was to assess the relationship of cluster of differentiation 117 (CD117) expression with the clinicopathological characteristics and the prognosis in patients with non-small cell lung cancer (NSCLC). No meta-analysis concerning the correlation of CD117 expression with clinical and prognostic values of the patients with NSCLC is reported. A systematic literature search was conducted to achieve eligible studies. The combined odds ratios (ORs) or hazard ratios (HRs: multivariate Cox analysis) with their 95% confidence intervals (CIs) were calculated in this analysis. Final 17 eligible studies with 4,893 NSCLC patients using immunohistochemical detection were included in this meta-analysis. CD117 expression was not correlated with gender (male vs. female), clinical stage (stages 3-4 vs. stages 1-2), tumor grade (grade 3 vs. grades 1-2), T-stage (T-stages 3-4 vs. T-stages 0-2), distal metastasis, and disease-free survival (DFS) of NSCLC (all p values >0.05). CD117 expression was associated with lymph node metastasis (positive vs. negative: OR = 0.74, 95% CI = 0.56-0.97, p = 0.03), histological type (adenocarcinoma (AC) versus squamous cell carcinoma (SCC): OR = 1.74, 95% CI = 1.26-2.39, p = 0.001), and a worse overall survival (OS) (HR = 1.89, 95% CI = 1.22-2.92, p = 0.004). The expression of CD117 was significantly higher in AC than in SCC. CD117 may be an independent prognostic indicator for worse OS in NSCLC.

A review of predictive, prognostic and diagnostic biomarkers for non-small-cell lung cancer: towards personalised and targeted cancer therapy

Introduction:

Lung cancer has a high mortality rate mainly due to the lack of early detection or outward signs and symptoms, thereby often progressing to advanced stages (e.g., stage IV) before it is diagnosed. However, if lung cancers can be diagnosed at an early stage and also if clinicians can prospectively identify patients likely to respond to specific treatments, then there is a very high potential to increase patients’ survival. In recent years, several investigations have been conducted to identify cancer biomarkers for lung cancer risk assessment, early detection and diagnosis, the likelihood of identifying the group of patients who will benefit from a particular treatment and monitoring patient response to treatment.

Materials and Methods:

This paper reports on the review of 19 current clinical and emerging biomarkers used in risk assessment, screening for early detection and diagnosis and monitoring the response of treatment of non-small-cell lung cancers.

Conclusion:

The future holds promise for personalised and targeted medicine from prevention, diagnosis to treatment, which take into account individual patient’s variability, though it depends on the development of effective biomarkers interrogating the key aberrant pathways and potentially targetable with molecular targeted or immunologic therapies. Lung cancer biomarkers have the potential to guide clinical decision-making since they can potentially detect the disease early, measure the risk of developing the disease and the risk of progression, provide accurate information of patient response to a specific treatment and are capable of informing clinicians about the likely outcome of a cancer diagnosis independent of the treatment received. Moreover, lung cancer biomarkers are increasingly linked to specific molecular pathway deregulations and/or cancer pathogenesis and can be used to justify the application of certain therapeutic or interventional strategies.

Relative influence of c-Kit expression and epidermal growth factor receptor gene amplification on survival in patients with non-small cell lung cancer

c-Kit and epidermal growth factor receptor (EGFR) have critical roles in cell proliferation and differentiation in patients with non-small cell lung cancer (NSCLC). The present study aimed to investigate the prognostic impact of c-Kit and/or EGFR expression in tumor tissue samples from 146 patients with NSCLC. c-Kit expression was analyzed using immunohistochemistry and the expression of EGFR was assessed using fluorescence in situ hybridization. Univariate and multivariate analyses identified that c-Kit is a significant negative prognostic factor. The expression of c-Kit was correlated with poor differentiation, pleura involvement and smoking history (P=0.043, 0.007 and 0.032, respectively). Furthermore, patients with c-Kit-positive expression were associated with a significantly lower overall survival compared with those exhibiting c-Kit-negative expression (P=0.048). The median follow-up time was 19 months post-surgery. EGFR gene amplification as a result of polysomy of chromosome 7 was found to be negatively correlated with poor differentiation and smoking history (P=0.023 and 0.044, respectively). The findings of the present study indicate that c-Kit and EGFR expression is a strong, independent, negative prognostic factor in NSCLC.

Protein kinase C-δ-mediated recycling of active KIT in colon cancer

PURPOSE

Abnormal signaling through receptor tyrosine kinase (RTK) moieties is important in tumorigenesis and drug targeting of colorectal cancers. Wild-type KIT (WT-KIT), a RTK that is activated upon binding with stem cell factor (SCF), is highly expressed in some colon cancers; however, little is known about the functional role of SCF-dependent KIT activation in colon cancer pathogenesis. We aimed to elucidate the conditions and roles of WT-KIT activation in colon cancer tumorigenesis.

EXPERIMENTAL DESIGN

Colorectal cancers with KIT expression were characterized by immunoblotting and immunohistochemistry. The biologic alterations after KIT-SCF binding were analyzed with or without protein kinase C (PKC) activation.

RESULTS

We found that WT-KIT was expressed in a subset of colon cancer cell lines and was activated by SCF, leading to activation of downstream AKT and extracellular signal-regulated kinase (ERK) signaling pathways. We also showed that KIT expression gradually decreased, after prolonged SCF stimulation, due to lysosomal degradation. Degradation of WT-KIT after SCF binding was significantly rescued when PKC was activated. We also showed the involvement of activated PKC-δ in the recycling of WT-KIT. We further showed that a subset of colorectal cancers exhibit expressions of both WT-KIT and activated PKC-δ and that expression of KIT is correlated with poor patient survival (P = 0.004).

CONCLUSIONS

Continuous downstream signal activation after KIT-SCF binding is accomplished through PKC-δ-mediated recycling of KIT. This sustained KIT activation may contribute to tumor progression in a subset of colon cancers with KIT expression and might provide the rationale for a therapeutic approach targeting KIT.