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Effect of the MiR-99b and MiR-135b on peritoneal carcinomatosis and liver metastasis in colorectal cancer

Highlight

  • miRNAs are associated with colorectal cancer, peritonitis carcinomatosis, and liver metastasis.

  • The miR-99b, miR-135b, and Akt protein levels, which are highly expressed in peritonitis carcinomatosis and liver metastasis tissues in colorectal cancer play a fundamental role in carcinomatosis and metastasis.

  • While miR-99b is highest in the primary tumor, its decrease in liver metastasis suggests that miR-99b may have a protective effect against liver metastasis.

  • miR-135 in the highest peritonitis carcinomatosis and liver metastasis compared to the main tissue suggests that it progresses to carcinomatosis and metastasis.

Abstract

Aim

This study aimed to evaluate the expression levels of miR-99b and miR-135b in peritoneal carcinoma and liver metastases associated with Colorectal Cancer (CRC), assess their association with the intracellular signaling pathway proteins Kirsten Rat Sarcoma Virus (KRAS) and Akt, and investigate their effects on survival.

Materials and methods

Changes in the KRAS gene and Akt proteins, expression levels of miR-99b and miR-135b, and factors affecting survival were compared between colorectal cancer-associated peritoneal carcinomatosis and liver metastasis.

Results

The expression levels of miR-99b and miR-135b and the immunohistochemical grade classification score of Akt were higher in colorectal cancer, peritoneal carcinomatosis, and liver metastasis than in normal tissues (p< 0.05). MiR-99b expression was highest in CRC, whereas miR-135b expression was highest in peritoneal carcinomatosis (p< 0.05). The expression level of miR-99b decreased and that of miR-135b increased in peritoneal and liver metastases compared with that in the tumor tissue. MiR-99b, Akt, and recurrence were risk factors that affected the overall survival rate in the model of clinical predictions (p= 0.045, p= 0.006, and p= 0.012, respectively).

Conclusion

While the expression of miR-99b was highest in the primary tumor, its decrease in liver metastasis and peritoneal carcinomatosis suggests that miR-99b has a protective effect against liver metastasis and peritoneal carcinomatosis. However, the detection of miR-135b expression was highest in peritoneal carcinomatosis and liver metastasis compared with that in the colorectal cancer tissues suggesting that it facilitates peritoneal carcinomatosis and liver metastasis. Furthermore, miR-99b, KRAS mutations, and Akt are risk factors for the overall survival of colorectal cancer.

Keywords
Colorectal cancer; Liver metastasis; MiR-99b; MiR-135b; Peritonitis carcinomatosis

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