Focal adhesion kinase (FAK) is an important mediator of extracellular matrix integrin signaling, cell motility, cell proliferation and cell survival. Increased FAK expression is observed in a variety ...of solid human tumors and increased FAK expression and activity frequently correlate with metastatic disease and poor prognosis. Herein we identify miR-7 as a direct regulator of FAK expression. miR-7 expression is decreased in malignant versus normal breast tissue and its expression correlates inversely with metastasis in human breast cancer patients. Forced expression of miR-7 produced increased E-CADHERIN and decreased FIBRONECTIN and VIMENTIN expression in breast cancer cells. The levels of miR-7 expression was positively correlated with E-CADHERIN mRNA and negatively correlated with VIMENTIN mRNA levels in breast cancer samples. Forced expression of miR-7 in aggressive breast cancer cell lines suppressed tumor cell monolayer proliferation, anchorage independent growth, three-dimensional growth in Matrigel, migration and invasion. Conversely, inhibition of miR-7 in the HBL-100 mammary epithelial cell line promoted cell proliferation and anchorage independent growth. Rescue of FAK expression reversed miR-7 suppression of migration and invasion. miR-7 also inhibited primary breast tumor development, local invasion and metastatic colonization of breast cancer xenografts. Thus, miR-7 expression is decreased in metastatic breast cancer, correlates with the level of epithelial differentiation of the tumor and inhibits metastatic progression.
X-linked inhibitor of apoptosis protein (XIAP) possesses a critical role in promotion of cell survival and maintenance of cellular homeostasis. In cancer, elevated XIAP expression has been associated ...with malignancy, poor prognosis, and treatment resistance. However, the underlying mechanisms of these effects remain unclear. XIAP has previously been proposed to promote tumor growth through suppression of autophagy. In this study, we examined the expression of XIAP and p62, two critical mediators of autophagy, in breast and colon cancer. We observed a negative correlation between XIAP and p62 expression in normal and cancer tissues of breast and colon, and that the ratio of XIAP and p62 expression determines the cancer phenotype. In vitro, we observed that XIAP interacted with p62 and also that XIAP depletion resulted in increased expression of p62. XIAP functioned as an ubiquitination E3 ligase towards p62 and suppressed p62 expression through ubiquitin-proteasomal degradation. Furthermore, XIAP enhanced cancer cell proliferation, viability, and colony formation in vitro via suppression of p62. In addition, we demonstrated that XIAP-enhanced tumor growth is dependent on depletion of p62 in vivo. Herein, we have therefore delineated a novel mechanism by which XIAP contributes to development and progression of breast and colon carcinoma.
The role of TMED3 involved in cancers has been seldom described, let alone in breast cancer. To explore the clinicopathological significance of TMED3 expression and the biological roles involved in ...breast cancer cells, we undertook the study.
Immunohistochemistry was performed to observe the pattern of TMED3 expression in breast cancer tissues, totaling 224 cases; followed by detailed statistical analysis between TMED3 expression versus clinicopathological information available. To explore the role of TMED3 involved in the malignant behaviors of breast cancer cells, wound-healing and Transwell assays were conducted to evaluate the variation of migration and invasion of MCF-7 and MDA-MB-231 cells whose TMED3 has been stably silenced using lenti-viral based short hairpin RNA (shRNA) vectors. MTT, clonogenic assay and xenograft nude mice model were undertaken to observe the variation of proliferation both in vitro and in vivo.
It was shown that elevated TMED3 markedly correlated with ER, PR, Her-2 status, and lymph nodes metastases in addition to significant association with poor overall prognosis. In vitro, TMED3 was shown to promote proliferation, migration and invasion of breast cancer cells. Moreover, miR-188-3p was identified as a novel negative regulator of TMED3 in breast cancer, which can slow down the proliferation, migration and invasion of MCF-7 cells. Results from in vivo xenograft nude mice models showed that lenti-viral based miR-188-3p re-expression can markedly impair the tumor growth.
Our data define and bolster the oncogenic role of TMED3 in breast cancer.
Human growth hormone (hGH) plays critical roles in pubertal mammary gland growth, development, and sexual maturation. Accumulated studies have reported that autocrine/paracrine hGH is an ...orthotopically expressed oncoprotein that promotes normal mammary epithelial cell oncogenic transformation. Autocrine/paracrine hGH has also been reported to promote mammary epithelial cell epithelial-mesenchymal transition (EMT) and invasion. However, the underlying mechanism remains largely obscure. MicroRNAs (miRNAs) are reported to be involved in regulation of multiple cellular functions of cancer. To determine whether autocrine/paracrine hGH promotes EMT and invasion through modulation of miRNA expression, we performed microarray profiling using MCF-7 cells stably expressing wild type or a translation-deficient hGH gene and identified miR-96-182-183 as an autocrine/paracrine hGH-regulated miRNA cluster. Forced expression of miR-96-182-183 conferred on epithelioid MCF-7 cells a mesenchymal phenotype and promoted invasive behavior in vitro and dissemination in vivo. Moreover, we observed that miR-96-182-183 promoted EMT and invasion by directly and simultaneously suppressing BRMS1L (breast cancer metastasis suppressor 1-like) gene expression. miR-96 and miR-182 also targeted GHR, providing a potential negative feedback loop in the hGH-GHR signaling pathway. We further demonstrated that autocrine/paracrine hGH stimulated miR-96-182-183 expression and facilitated EMT and invasion via STAT3 and STAT5 signaling. Consistent with elevated expression of autocrine/paracrine hGH in metastatic breast cancer tissue, miR-96-182-183 expression was also remarkably enhanced. Hence, we delineate the roles of the miRNA-96-182-183 cluster and elucidate a novel hGH-GHR-STAT3/STAT5-miR-96-182-183-BRMS1L-ZEB1/E47-EMT/invasion axis, which provides further understanding of the mechanism of autocrine/paracrine hGH-stimulated EMT and invasion in breast cancer.
Background: hGH is an orthotopically expressed oncoprotein associated with mammary epithelial cell tumorigenesis.
Results: The miR-96-182-183 cluster is regulated by autocrine/paracrine hGH and targets BRMS1L and GHR.
Conclusion: Autocrine/paracrine hGH promotes breast cancer epithelial-mesenchymal transition and invasion via stimulating the miRNA-96-182-183 cluster.
Significance: Autocrine/paracrine hGH and the miR-96-182-183 cluster might be exploited as a therapy or prognostic marker for breast cancer.
Background:
Owing to the heterogeneity displayed by hepatocellular carcinoma (HCC) and the complexity of tumor microenvironment (TME), it is noted that the long-term effectiveness of the cancer ...therapy poses a severe clinical challenge. Hence, it is essential to categorize and alter the treatment intervention decisions for these tumors.
Materials and methods:
“ConsensusClusterPlus” tool was used for developing a secure molecular classification system that was based on the cuproptosis-linked gene expression. Furthermore, all clinical properties, pathway characteristics, genomic changes, and immune characteristics of different cell types involved in the immune pathways were also assessed. Univariate Cox regression and the least absolute shrinkage and selection operator (Lasso) analyses were used for designing the prognostic risk model associated with cuproptosis.
Results:
Three cuproptosis-linked subtypes (clust1, clust2, and clust3) were detected. Out of these, Clust3 showed the worst prognosis, followed by clust2, while Clust1 showed the best prognosis. Three subtypes had significantly different enrichment in pathways related to Tricarboxylic Acid (TCA) cycle, cell cycle, and cell senescence (
p
< 0.01). The clust3 subtype with poor prognosis had a low “ImmuneScore” and low immune cell infiltration, and the three subtypes had significant differences in the antigen processing and presentation pathway of the macrophages. Clust1 had a low TIDE score and was sensitive to immunotherapy. Then, according to the prognosis-related genes of cuproptosis, a prognosis risk model related to cuproptosis was constructed, containing seven genes (KIF2C, PTTG1, CENPM, CDC20, CYP2C9, SFN, and CFHR3). “High” group had a higher TIDE score compared to the TIDE score value shown by the “Low” group, which benefited less from immunotherapy, whereas the “High” group patients were more sensitive to the conventional drugs. Finally, the prognosis risk model related to cuproptosis was combined with clinical pathological characteristics to further improve the prognostic model and survival prediction.
Conclusion:
Three new molecular subgroups based on cuproptosis-linked genes were revealed, and a cuproptosis-related prognostic risk model comprising seven genes was established in this study, which could assist in predicting the prognosis and identifying the patients benefit from immunotherapy.
Clinical applications of siRNA therapeutics have been limited by the immunogenicity of the siRNA and low efficiency of siRNA delivery to target cells. Recently, evidence have shown that exosomes, ...endogenous nano-vesicles, can deliver siRNA to the tumor tissues in mice. Here, to reduce immunogenicity, we selected immature dendritic cells (DCs) to produce exosomes. In addition, tumor targeting was achieved by engineering the DCs to express exosomal membrane protein (Lamp2b), fused to av integrin-specific iRGD peptide (CRGDKGPDC). Next, iRGD targeted exosomes (iRGD-Exo) were isolated from the transfected DCs, and then the isolated exosomes were loaded with BCL6 siRNA by electroporation. Our results found that integrin (αvβ3) receptors were highly expressed on OCI-Ly8 cells. In addition, iRGD-Exo showed high targeting ability with avβ3 integrins positive OCI-Ly8 cells. Significantly, iRGD-Exo loaded with BCL6 siRNA suppressed DLBCL cell proliferation
in vitro
. Furthermore, intravenously injected iRGD-Exo delivered BCL6 siRNA to tumor tissues, resulting in inhibition of tumor growth in DLBCL. Meanwhile, exosomes mediated BCL6 siRNA delivery did not exhibit appreciable toxicity in mice. Collectively, our study demonstrates a therapeutic potential of exosomes as a promising vehicle for RNAi delivery to treat DLBCL.
Gastric cancer remains a malignancy with poor survival outcome. We herein report that GSE1, a proline-rich protein, possesses a role in the progression of human gastric cancer. The expression of GSE1 ...was observed to be much higher in human gastric cancer tissues compared with normal gastric tissues, and GSE1 expression correlated positively with lymph node metastasis, histological grade, depth of invasion, and clinical stage in gastric cancer patients. Moreover, GSE1 expression was also associated with decreased post-operative relapse-free survival and overall survival in the cohort. The forced expression of GSE1 in gastric cancer cell lines resulted in increased cell proliferation, increased colony formation, enhanced cell migration, and invasion. Furthermore, forced expression of GSE1 also increased tumor size and enhanced lung metastasis in xenograft models. The depletion of endogenous GSE1 with shRNAs decreased the oncogenicity and invasiveness of gastric cancer cells both in vitro and in vivo. In addition, GSE1 was determined to be a direct target of miR-200b and miR-200c. Furthermore, GSE1 positively regulated the downstream gene SLC7A5 (also known as LAT-1), which was scanned and verified from mRNA sequencing. GSE1 therefore possesses an oncogenic role in human gastric cancer, and targeted therapeutic approaches to inhibit GSE1 function in gastric cancer warrant further consideration.
Screening of the entire let-7 family of microRNAs (miRNA) by in situ hybridization identified let-7g as the only member, the diminished expression of which was significantly associated with lymph ...node metastasis and poor survival in breast cancer patients. Abrogation of let-7g expression in otherwise nonmetastatic mammary carcinoma cells elicited rapid metastasis from the orthotopic location, through preferential targets, Grb2-associated binding protein 2 (GAB2) and fibronectin 1 (FN1), and consequent activation of p44/42 mitogen-activated protein kinase (MAPK) and specific matrix metalloproteinases. Treatment with estrogen or epidermal growth factor specifically reduced the expression of mature let-7g through activation of p44/42 MAPK and subsequently stimulated expression of GAB2 and FN1, which, in turn, promoted tumor invasion. We thus identify let-7g as a unique member of the let-7 miRNA family that can serve as a prognostic biomarker in breast cancer and also propose a paradigm used by specific signaling molecules via let-7g to cooperatively promote breast cancer invasion and metastasis. Thus, let-7 family members neither possess equivalent clinicopathologic correlation nor function in breast cancer.
Alternative polyadenylation (APA) is an important mechanism of gene expression regulation through generation of RNA isoforms with distinct 3' termini. Increasing evidence has revealed that APA is ...actively involved in development and disease, including hepatocellular carcinoma (HCC). However, how APA functions in tumor formation and progression remains elusive. In this study, we investigated the role of cleavage factor I (CFIm) subunit CPSF6 in human hepatocellular carcinoma (HCC).
Expression levels of CPSF6 in clinical tissues and cell lines were determined by qRT-PCR and western blot. Functional assays, including the cell number, MTT, colony formation and transwell, were used to determine the oncogenic role of CPSF6 in HCC. Animal experiments were used to determine the role of CPSF6 in HCC tumorigenicity in vivo. Deep sequencing-based 3 T-seq was used to profile the transcriptome-wide APA sites in both HCC cells and CPSF6 knockdown HCC cells. The function of CPSF6-affected target NQO1 with distinct 3'UTRs was characterized by metabolism assays.
We observed CPSF6 was upregulated in HCC and the high expression of CPSF6 was associated with poor prognosis in patients. Overexpression of CPSF6 promoted proliferation, migration and invasion of HCC cells in vitro and in vivo. Transcriptome-wide APA profiling analysis indicated that high expression of CPSF6 promoted the favorable usage of the proximal poly(A) site in the 3'UTR of NQO1. We demonstrated CPSF6-induced tumorigenic activities were mediated by the NQO1 isoform with short 3'UTR. Furthermore, we found that CPSF6 induced metabolic alterations in liver cells through NQO1.
CPSF6 plays a critical role in HCC progression by upregulating NQO1 expression through APA. These findings provide evidence to demonstrate that APA of NQO1 contributes to HCC progression and may have implications for developing new therapeutic strategy against this disease.
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