Shank-associated RH domain-interacting protein expression is upregulated in entodermal and mesodermal cancer or downregulated in ectodermal malignancy

Shank-associated RH domain-interacting protein (SHARPIN) is a type of linear ubiquitin chain-associated protein, which serves an important role in cell proliferation, apoptosis, organ development, immune and inflammatory reaction, initiation and development of malignant tumors. To evaluate SHARPIN expression in multiple malignant tumors derived from different germ layers, 14 types of cancer and their corresponding normal tissues were examined. Immunohistochemistry was performed to semi-quantify SHARPIN expression in multiple malignant tumors, and immunofluorescence was performed to evaluate the subcellular localization of SHARPIN in various malignant tumors. All the recruited cancer and paracancer samples originated from entoderm and mesoderm showed an upregulated expression of SHARPIN, whereas the cancer types that originated from ectoderm exhibited a downregulated or loss of SHARPIN expression. SHARPIN was primarily localized in the cytoplasm of cells and exhibited a faint signal in the nucleus, with the exception for lung cancer and esophagus cancer, in which malignant cells had aberrantly large nuclei and limited cytoplasm, which produced a signal in the nucleus but not in the cytoplasm. Conclusively, SHARPIN expression was upregulated in entodermal and mesodermal cancer types, but downregulated in ectodermal cancer types, indicating SHARPIN could act as either oncogene or anti-oncogene in malignant tumors derived from different germ layers.