SET7/9 inhibits oncogenic activities through regulation of Gli-1 expression in breast cancer.

SET7/9 is a protein lysine methyltransferase that had been initially identified as a histone lysine methyltransferase which generates monomethylation at histone 3 lysine 4. Different functions were attributed to the protein methylation mediated by SET7/9. In this study, we found that the expression of SET7/9 declined in a majority of the human breast cancer tissues examined compared with normal tissues. Knockdown of SET7/9 promoted the proliferation, migration, and invasion of breast cancer cells. Knockdown of SET7/9 also increased the tumorigenicity of breast cancer cells in vivo. On the contrary, overexpression of SET7/9 in breast cancer cells inhibited these processes. Microarray analysis indicated that Gli-1 may play function as a downstream factor of SET7/9. Overexpression of SET7/9SET7/9 inhibits Gli-1 expression. While knockdown of SET7/9 promotes the expression of Gli-1. Gli-1 inhibited by cyclopamine blocked knockdown SET7/9-driven proliferation, migration, and invasion in breast cancer cell. Furthermore, Gli-1 expression in human breast cancer tissues is negatively correlated with SET7/9 expression. Together, these results helped to realize the antioncogene functions of SET7/9 in breast cancer cells and provided a novel direction to treat breast cancer.

Tripartite motif 16 inhibits epithelial-mesenchymal transition and metastasis by down-regulating sonic hedgehog pathway in non-small cell lung cancer cells.

The present study was to examine the effect of Tripartite motif 16 (TRIM16) on epithelial-mesenchymal transition (EMT) and metastasis in non-small cell lung cancer (NSCLC) cells, and its clinical significance in NSCLC. The correlation of TRIM16 expression and clinical features of NSCLC was analyzed in paraffin-embedded archived normal lung tissues and NSCLC tissues by immunohistochemical analysis. The effect of TRIM16 on EMT and metastasis was examined both in vitro and in vivo. The expression of TRIM16 was markedly decreased in NSCLC and correlated with tumor metastasis. Upregulation of TRIM16 significantly inhibited EMT and metastasis of NSCLC cells. In contrast, silencing TRIM16 expression significantly promoted the EMT and metastasis of NSCLC cells both in vitro and in vivo. Moreover, we demonstrated that downregulation of TRIM16 activated the sonic hedgehog pathway, and that inhibition of the sonic hedgehog pathway by cyclopamine abrogated the effect of TRIM16-downregulation induced EMT and metastasis on NSCLC cells. Our results suggest that TRIM16 is a potential pharmacologic target for the treatment of NSCLC and promotion TRIM16 expression might represent a novel strategy to NSCLC metastasis.

GATA6 is overexpressed in breast cancer and promotes breast cancer cell epithelial-mesenchymal transition by upregulating slug expression.

Metastasis is the leading cause of death in breast cancer (BC) patients. However, until now, the mechanisms of BC metastasis remain elusive. GATA6 is a member of the GATA transcription factor family that plays critical regulatory roles in tissue development, which has been proposed as an oncogene in many types of tumors; however, its role and underlying mechanisms in BC remain unclear. Here we show that GATA6 is elevated in BC and its expression level is positively correlated with metastasis. In addition Kaplan-Meier survival analysis showed that high expression of GATA6 was associated with decreased overall survival of BC patients. Overexpression of GATA6 in BC cells increased epithelial-mesenchymal transition. In contrast, silencing GATA6 in aggressive BC cells inhibited this process. Mechanistically, we found GATA6 exerts its function through active slug transcription. Slug knockdown blocked the GATA6-driven EMT. Furthermore, slug expression in human BC is positively correlated with GATA6 expression. Our results, for the first time, portray a pivotal role of GATA6 in regulating metastatic behaviors of BC cells, suggesting GATA6 is a potential therapeutic target in metastatic BCs.

[Retracted] Tripartite motif 16 suppresses breast cancer stem cell properties through regulation of Gli­1 degradation via the ubiquitin­proteasome pathway.

Following the publication of the above paper, it was drawn to the Editors' attention by a concerned reader that the data obtained from sphere­forming assay experiments shown in Figs. 4C­F and 8B and C, and western blotting data in Figs. 4A and 8A, were strikingly similar to data appearing in different form in other articles by different authors from different research institutes that had already been published, one of which has been retracted. Moreover, a pair of data panels comparing between Fig. 4E and 8C were partly overlapping, such that these data appear to have been derived from the same original source. Owing to the fact that the contentious data in the above article had already been published elsewhere prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 35: 1204­1212, 2016; DOI: 10.3892/or.2015.4437].

SphK1 promotes development of non­small cell lung cancer through activation of STAT3.

Sphingosine kinase1 (SphK1) is an oncogenic enzyme that regulates tumor cell apoptosis, proliferation and survival. SphK1 has been reported to promote the development of non­small cell lung cancer (NSCLC), although the underlying mechanism remains to be determined. The aim of the present study was to examine the expression and function of SphK1 in NSCLC and to explore the underlying molecular mechanism. The results of the present study demonstrated that SphK1 expression was upregulated in NSCLC tissues and cell lines. Overexpression of SphK1 increased the proliferation and migration of NSCLC cells. Additionally, overexpression of SphK1 induced expression of antiapoptotic and migration­associated genes, such as Bcl­2, matrix metallopeptidase 2 and cyclin D1. Of note, signal transducer and activator of transcription 3 (STAT3) was also activated in the SphK1­overexpressing cells. By treatment with a STAT3 inhibitor, it was demonstrated that the SphK1­induced changes in expression of target genes, as well as the increase in proliferation and migration of NSCLC cells were mediated by STAT3. In conclusion, the effects of SphK1 overexpression on the development of NSCLC were demonstrated to be mediated by the activation of STAT3. These results suggested that inhibition of the SphK1­STAT3 axis may be a potential strategy for the treatment of NSCLC.

Efficacy Analysis of Adjuvant Chemotherapy with Gemcitabine Plus Platinum or S-1 in Biliary Tract Carcinoma: A Multi-Center Retrospective Study.

PURPOSE: Biliary tract cancers (BTCs) have a poor overall prognosis, as patients who underwent curative surgery frequently experience disease recurrence. At present, there is a paucity of well-documented adjuvant chemotherapy regimen. This study aimed to assess whether gemcitabine plus platinum or S-1 adjuvant chemotherapy have different impact on relapse-free survival (RFS). PATIENTS AND METHODS: We selected patients undergoing radical biliary tract cancer surgery, pathologically confirmed adenocarcinoma and received gemcitabine plus platinum (cisplatin or oxaliplatin) or S-1 adjuvant chemotherapy from September 2013 to May 2020. The primary study endpoint was RFS. The secondary endpoint was safety. RESULTS: Overall 136 patients were enrolled. The median follow-up was 32.3 months and the median RFS was 17.0 months (95% CI 8.9-25.1). The median RFS was 14.1 months (95% CI 6.7-21.5) in gemcitabine plus platinum group and 33.0 months (95% CI 9.3-56.7) in gemcitabine plus S-1 (GS) group, a non-significant difference both in univariate (P=0.092) and in multivariate analysis (P=0.058). Lymph node status (N- vs N+: HR=0.477, 95% CI 0.285-0.799; P=0.005) and chemotherapy cycles (<6 vs 6-8: HR=1.828, 95% CI 1.117-2.993; P=0.016) were independent impact factors for RFS. GS group had lower incidence of adverse reactions. CONCLUSION: Compared with gemcitabine plus platinum, GS regimen has a tendency to obtain longer RFS (although there is no statistically significant difference) and less toxic. GS regimen has the potential to be investigated as a standard regimen for adjuvant chemotherapy.

ABCB5-ZEB1 Axis Promotes Invasion and Metastasis in Breast Cancer Cells.

ABCB5 belongs to the ATP-binding cassette (ABC) superfamily, which is recognized for playing a role in the failure of chemotherapy. ABCB5 has also been found to be overexpressed at the transcriptional level in a number of cancer subtypes, including breast cancer. However, the exact mechanism ABCB5 uses on cancer cell metastasis is still unclear. In the present study, we demonstrate that ABCB5 expression was increased in metastatic tissues when compared with nonmetastatic tissues. ABCB5 can significantly enhance metastasis and epithelial-mesenchymal transition (EMT), while knockdown of ABCB5 inhibited these processes. Microarray analysis indicated that ZEB1 may function as a downstream factor of ABCB5. Furthermore, the expression of ZEB1 in tissues is positively relevant to ABCB5 in breast cancer. Knocking down ZEB1 inhibits ABCB5 ectopic expression-induced migration and invasion, as well as EMT. Taken together, these results helped to realize the oncogene functions of ABCB5 in breast cancer cells and provided a new direction in treating breast cancer.

Tripartite motif 16 suppresses breast cancer stem cell properties through regulation of Gli-1 degradation via the ubiquitin-proteasome pathway.

Cancer stem cells (CSCs) are responsible for cancer progression and patient prognosis. Tripartite motif 16 (TRIM16) is a proteasome coactivator that regulates proteolytic activity in eukaryotic cells. Abundant evidence has shown that TRIM16 is lowly expressed in a number of human carcinomas. In a previous study, we demonstrated that TRIM16 suppressed cancer malignancy and that TRIM16 expression levels were associated with favorable prognostic parameters of patients with cancer. However, the precise role of this motif in the pathogenesis of breast cancer remains unknown. In the present study, we examined 29 human breast cancer specimens, and found that TRIM16 was lowly expressed in breast cancers; thus, TRIM16 expression is negatively correlated with metastasis in breast cancer patients. Moreover, we showed that TRIM16 suppressed CSC properties in a population of breast cancer cells. TRIM16 depletion resulted in an increased proportion of CSCs relative to breast cancer cells when several assays were used to assess CSC properties. Finally, we demonstrated that TRIM16 directly regulated the degradation of Gli­1 protein via the ubiquitin­proteasome pathway. In conclusion, we propose that inhibition of CSC properties may be one of the functions of TRIM16 as a suppressor of breast cancer progression.

Cullin3 promotes breast cancer cells metastasis and epithelial-mesenchymal transition by targeting BRMS1 for degradation.

Metastasis is the leading cause of death in breast cancer (BC) patients. However, until now, the mechanisms of BC metastasis remain elusive. Cullin3 is a highly conserved Cullin family member present in the genomes of all eukaryotes, which has been proposed as an oncogene in many types of tumors; however, its role and underlying mechanisms in BC remain unclear. Here we show that Cullin3 is elevated in BC and its expression level is positively correlated with metastasis. Overexpression of Cullin3 in BC cells increased proliferation, epithelial-mesenchymal transition, migration and invasion in vitro, and enhanced tumorigenic and metastatic capacities in vivo. In contrast, silencing Cullin3 in aggressive and invasive BC cells inhibited these processes. Mechanistically, we found Cullin3 exerts its function through promoting BRMS1 protein degradation, which was associated with EMT, migration and invasion. BRMS1 overexpression blocked Cullin3-driven EMT, and metastasis. Our results, for the first time, portray a pivotal role of Cullin3 in stimulating metastatic behaviors of BC cells. Targeting Cullin3 may thus be a useful strategy to impede BC cell invasion and metastasis.