The E-cadherin/epidermal growth factor receptor interaction: a hypothesis of reciprocal and reversible control of intercellular adhesion and cell proliferation

Molecular targets for prediction of prognosis and treatment response in esophageal squamous cell carcinoma

In recent years, molecular targets for prediction of prognosis and chemotherapy efficacy in esophageal squamous cell carcinoma (ESCC) have been increasingly identified, which involve up-regulation of growth signals, down-regulation of inhibitory growth signals, death avoidance, limitless replicative potential, continuous eternal angiogenesis, invasion, and metastasis. Typical molecular targets include mutant p53, vascular endothelial growth factor, epidermal growth factor receptor, and Ki-67. The clinical value of currently available molecular targets in prediction of prognosis and treatment response in ESCC needs to be further evaluated.

Changes of aberrant crypt foci in early colon cancer and its relationship with PPAR-γ and β-catenin

AIM: To observe the progression of proliferation and apoptosis of colorectal preneoplastic sequence, and to explore the potential role of abnormal expression pattern of PPAR-γ and β-catenin in the preneoplastic sequence.

METHODS: Colorectal ACFs and adenomas were induced using a modified DMH-induced carcinogenesis method in SD rats. The expression patterns of PPAR-γ and β-catenin in colorectal preneoplastic sequence were detected using immumohistochemisty. Proliferation and apoptosis of preneoplastic sequence were analyzed using Ki-67 and Bcl-2.

RESULTS: In the "Normal-ACF-Adenoma" sequence induced by DMH, abnormal expression of Ki-67 occurred at the transformation stage of "Normal-ACF". Positive nucleuses of Ki-67 distributed extensively within the aberrant crypt, differing from normal crypt significantly and similar to adenoma. Abnormally high expression of Bcl-2 appeared until ACF transformed to adenoma, presenting broad positive granules in the cytoplasm. PPAR-γ, as Ki-67 did, abnormally expressed during the "Normal-ACF" shift with extensive distribution of positive nucleuses. β-catenin, as Bcl-2 did, presented with different positive location and density until the transformation of "ACF-Adenoma" with evident positive nucleuses.

CONCLUSION: In the stage of "Normal-ACF", the main abnormality is higher proliferation rate found in aberrant crypt than normal crypt, and this change might be correlated to abnormal expression of PPAR-γ. Depression of apoptosis became obvious in the stage of "ACF-Adenoma", and the elevated expression of β-catenin and Bcl-2 might have a synergic role in the formation of adenoma.