Objective  To investigate Intraflagellar Transport 80 (IFT80) protein expression in bone, lung, pancreatic, stomach, intestinal, prostate, breast, and ovarian cancers to explore its mechanism in cancer cell proliferation and to diagnose and identify new targets in cancer treatment.

  Methods  Immunohistochemistry was used to investigate the expression of IFT80 in gastric cancer tissue of different stages and in eight other kinds of human cancer tissues. We studied the relationship between cancer cell proliferation and inhibition of IFT80. Immunofluorescence method and cell culture were used to study the cilia and IFT80.

  Results  Results showed the following: a) the expression of IFT80 was high in gastric and lung carcinoma tissues, moderate in breast and colorectal cancers, low in bone and ovarian cancers, and nearly absent in prostate and pancreatic cancers; b) inhibition of IFT80 in the A549 cancer cell line accelerated cell proliferation and resulted in shorter, lower quality cilia; and c) IFT80 was abundantly expressed in cancer tissues of well-differentiated stage-IIA gastric cancer and normal gastric tissues, but was hardly expressed in late-stage, poorly differentiated gastric cancer. IFT80 could have various degrees of expression in gastric carcinoma of other stages and differentiation.

  Conclusions  Different cancer organs showed variation in IFT80 expression. IFT80 can be distributed in the organs with mechanical motion function, such as lungs and stomach. IFT80 is distributed on the cell cilia and can adjust the number and length of the cilia by reducing IFT80 protein expression. Through a variety of ways, IFT80 directly or indirectly participates in the proliferation of cancer cells. Thus, the lowest or nearly zero expression of IFT80 can be seen in cancer tissues of high-grade malignancy, such as advanced cancers with poor differentiation.