Other
13 Authors
- Lin L,
- He AR,
- Cahn K,
- Gusev Y,
- Wang H,
- Wu Y,
- Chen S,
- Gao B,
- Zhi X,
- Kallakury B,
- Bhuvaneshwar K,
- Wang X,
- Marshall JL
| First Author | Lin L | Year | 2021 |
| Journal | Theranostics | Volume | 11 |
| Issue | 9 | Pages | 4232-4250 |
| PubMed ID | 33754058 | Mgi Jnum | J:314016 |
| Mgi Id | MGI:6807809 | Doi | 10.7150/thno.49819 |
| Citation | Lin L, et al. (2021) SPTBN1 inhibits inflammatory responses and hepatocarcinogenesis via the stabilization of SOCS1 and downregulation of p65 in hepatocellular carcinoma. Theranostics 11(9):4232-4250 |
| abstractText | Background: Spectrin, beta, non-erythrocytic 1 (SPTBN1), an adapter protein for transforming growth factor beta (TGF-beta) signaling, is recognized as a tumor suppressor in the development of hepatocellular carcinoma (HCC); however, the underlying molecular mechanisms of this tumor suppression remain obscure. Methods: The effects on expression of pro-inflammatory cytokines upon the inhibition or impairment of SPTBN1 in HCC cell lines and liver tissues of Sptbn1(+/-) and wild-type (WT) mice were assessed by analyses of quantitative real-time reverse-transcription polymerase chain reaction (QRT-PCR), enzyme linked immunosorbent assay (ELISA), Western blotting and gene array databases from HCC patients. We investigated the detailed molecular mechanisms underlying the inflammatory responses by immunoprecipitation-Western blotting, luciferase reporter assay, chromatin immunoprecipitation quantitative real time PCR (ChIP-qPCR), immunohistochemistry (IHC) and electrophoretic mobility shift assay (EMSA). The proportion of myeloid-derived suppressor cells in liver, spleen, bone marrow and peripheral blood samples from WT and Sptbn1(+/-) mice were measured by fluorescence-activated cell sorting (FACS) analysis. Further, the hepatocacinogenesis and its correlation with inflammatory microenvironment by loss of SPTBN1/SOCS1 and induction of p65 were analyzed by treating WT and Sptbn1(+/-) mice with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC). Results: Loss of SPTBN1 in HCC cells upregulated the expression of pro-inflammatory cytokines including interleukin-1alpha (IL-1alpha), IL-1beta, and IL-6, and enhanced NF-kappaB transcriptional activation. Mechanistic analyses revealed that knockdown of SPTBN1 by siRNA downregulated the expression of suppressor of cytokine signaling 1 (SOCS1), an E3 ligase of p65, and subsequently upregulated p65 accumulation in the nucleus of HCC cells. Restoration of SOCS1 abrogated this SPTBN1 loss-associated elevation of p65 in HCC cells. In human HCC tissues, SPTBN1 gene expression was inversely correlated with gene expression of IL-1alpha, IL-1beta and IL-6. Furthermore, a decrease in the levels of SPTBN1 gene, as well as an increase in the gene expression of IL-1beta or IL-6 predicted shorter relapse free survival in HCC patients, and that HCC patients with low expression of SPTBN1 or SOCS1 protein is associated with poor survival. Heterozygous loss of SPTBN1 (Sptbn1(+/-) ) in mice markedly upregulated hepatic expression of IL-1alpha, IL-1beta and IL-6, and elevated the proportion of myeloid-derived suppressor cells (MDSCs) and CD4(+)CD25(+)Foxp3(+) regulatory T cells (Foxp3(+)Treg) cells in the liver, promoting hepatocarcinogenesis of mouse fed by DDC. Conclusions: Our findings provided evidence that loss of SPTBN1 in HCC cells increases p65 protein stability via the inhibition of SOCS1 and enhances NF-kappaB activation, stimulating the release of inflammatory cytokines, which are critical molecular mechanisms for the loss of SPTBN1-induced liver cancer formation. Reduced SPTBN1 and SOCS1 predict poor outcome in HCC patients. |
