Objective To investigate the expression of phosphatase and tensin homolog gene (PTEN) and 1-phosphatidylinositol 3-kinase (PI3K) in rectal cancer and its correlation with clinical pathology.Methods MaxVisionTM immunohistochemical method was used to detect the expressions of PTEN and PI3K in 60 rectal cancer tissues,30 adenoma tissues and 10 normal rectal tissues,and the correlation between the expression levels and its clinicopathologic characteristics was discussed.Results The positive expression rate of PTEN in rectal cancer tissue was significantly lower than that in normal rectal tissue and adenoma tissue [43.3％ (26/60) vs.100.0％ (10/10),93.3％ (28/30),P ＜ 0.05].The positive expression rate of PI3K in rectal cancer tissue was significantly higher than that in normal rectal tissue and adenoma tissue [75.0％ (45/60) vs.30.0％ (3/10),33.3％ (10/30),P ＜ 0.05].The positive expression of PTEN and PI3K were correlated with carcinoembryonic antigen,degree of cell differentiation,TNM stage,lymph node metastasis and distant metastasis(P＜ 0.01 or ＜ 0.05 ),but had no correlation with age,gender,neoplasm location,neoplasm appearance (P ＞ 0.05).The correlated analysis showed that the positive expression of PTEN had negative correlation with PI3K (r =-0.269,P =0.023 ).Conclusions The high expression of PI3K and down regulation of PTEN in rectal cancer are closely related to its invasion and metastasis.There are some values to monitor PTEN and PI3K expression for determining biological behavior of rectal cancer.

Objective To investigate the expression of metastasis associated gene-1 (mag-1) and mammalian target of rapamycin (mTOR) in rectal cancer, and its correlation with clinical pathology. Methods The expressions of mag-1 and mTOR in 60 rectal cancer tissue, 30 adenoma tissues and 10 normal rectal tissues were detected by immunohistochemical method, and the correlation between the expression levels and rectal cancer clinical pathologic characteristics was discussed. Results The positive expression rates of mag-1 and mTOR in rectal cancer tissue were significantly higher than those in normal rectal tissue and adenoma tissue:55%(33/60) vs. 1/10 and 27%(8/30), 58%(35/60) vs. 2/10 and 30% (9/30), and there were statistical differences (P<0.05). The expression levels of mag-1 and mTOR in rectal cancer tissue were correlated with carcinoembryonic antigen on admission, degree of cell differentiation, TNM stage, lymph node metastasis and distant metastasis (P<0.01 or<0.05), but had no correlation with age, gender, neoplasm location and neoplasm appearance (P > 0.05). The correlation analysis result showed that the expressions of mag-1 and mTOR were positively correlated in rectal cancer tissue (r=0.730, P<0.01). Conclusions The mag-1 and mTOR may correlate with invasion and metastasis in rectal cancer, and monitoring mag-1 and mTOR expression has a certain value for determining biological behavior of rectal cancer.

The tRNA-derived fragments (tRF and tiRNA) are a newly discovered type of non-coding RNA (ncRNA) that has been found to be stably expressed in peripheral blood. Studies have shown that tRF and tiRNA play important roles in human tumors by regulating multiple processes, including gene expression and silencing, cell proliferation and apoptosis, and protein translation. The tissue-speci-ficity, high abundance, and stability of tRF and tiRNA, along with their broad-spectrum functional roles, confer them significant advan-tages for use in the field of oncology research. There is increasing evidence that aberrantly expressed tRF and tiRNA may be potential biomarkers or therapeutic targets for tumor diagnosis and prognosis. This paper summarizes the source, structure, biological charac-teristics, and functions of different tRF and tiRNA subtypes and explores their potential relationship with tumors and their underlying mechanisms in order to provide a novel idea for the early diagnosis and targeted therapy of tumors.