Promotes Tumor Cell Proliferation Research Articles

Suppressed microRNA-195-5p expression in mycosis fungoides promotes tumor cell proliferation.

Several cancers, including mycosis fungoides (MF), have reported dysregulation of miR-195-5p. miR-195-5p plays a role in cell cycle regulation in several malignant diseases. This study aimed to investigate: (a) the expression level of miR-195-5p in lesional MF skin biopsies and (b) the potential regulatory roles of miR-195-5p in MF. Quantitative real-time polymerase chain reaction (RT-qPCR) was used to determine miR-195-5p expression in MF skin biopsies and cell lines. The effect of miR-195-5p and ADP-ribosylation factor-like protein 2 (ARL2) on cell cycle and apoptosis was measured by flow cytometry assays. Changes in ARL2 expression were determined by RT-qPCR and Western blotting (WB). We found lower expression levels of miR-195-5p in lesional skin from MF patients compared with non-lesional MF skin and skin from healthy volunteers. Additionally, miR-195-5p showed lower expression levels in the skin from patients with disease progression compared with patients with stable disease. In vitro studies showed that overexpression of miR-195-5p induced a cell cycle arrest in G0G1. Using microarray analysis, we identified several genes that were regulated after miR-195-5p overexpression. The most downregulated gene after miR-195-5p mimic transfection was ARL2. RT-qPCR and WB analyses confirmed downregulation of ARL2 following transfection with miR-195-5p mimic. Lastly, transfection with siRNA against ARL2 also induced a G0G1 arrest. Upregulation of miR-195-5p in MF inhibits cycle arrest by downregulation of ARL2. miR-195-5p may thus function as a tumor suppressor in MF and low miR-195-5p expression in lesional MF skin may promote disease progression.

<p>GINS2 Functions as a Key Gene in Lung Adenocarcinoma by WGCNA Co-Expression Network Analysis</p>

BackgroundLung adenocarcinoma is one of the malignant tumors in the world. This study aimed to explore the biological mechanism of GINS2 in lung adenocarcinoma.Materials and MethodsRaw data were downloaded from GEO. WGCNA co-expression network and PPI network were established to identify the hub gene. The expression profile and clinical features of GINS2 were collected from TCGA-LUAD cohort. Survival analysis in TCGA-LUAD cohort was plotted by R package. GSEA was analyzed via GSEA software. MTS, Transwell and apoptosis assays were used to detect the proliferation, migration and apoptotic abilities of lung adenocarcinoma cells.ResultsGINS2 was identified as the hub gene via WGCNA co-expression network and PPI network. Higher GINS2 expressions were observed in TCGA-LUAD cohort, GSE32863 and clinical samples dataset. Overexpression of GINS2 had a significantly negative connection with poor survival outcome. GSEA results revealed that GINS2 could be enriched in “HALLMARK_G2M_CHECKPOINT”, “HALLMARK_E2F_TARGETS”, “HALLMARK_DNA_REPAIR” and “HALLMARK_MYC_TARGETS_V2”. Overexpression of GINS2 promoted tumor cell proliferation and migration and suppressed cell apoptosis.ConclusionOur results explored that GINS2 functioned as an oncogene in lung adenocarcinoma, and suggested that GINS2 could act as a promising prognosis biomarker for lung adenocarcinoma.

Novel evidence for oncogenic piRNA-823 as a promising prognostic biomarker and a potential therapeutic target in colorectal cancer.

piRNA‐823 as a member of the piRNA family is reported to promote tumour cell proliferation in multiple myeloma and hepatocellular cancer. However, few studies on the function of piRNA‐823 in colorectal cancer (CRC). Our present study data showed that piRNA‐823 plays an oncogene role in CRC cells. Inhibition of piRNA‐823 can significantly inhibit the proliferation, invasion and apoptosis resistance of CRC cells. Mechanism studies have shown that piRNA‐823 inhibits the ubiquitination of hypoxia‐inducible factor‐1 alpha (HIF‐1α) by up‐regulating the expression of Glucose‐6‐phosphate dehydrogenase (G6PD) and ultimately up‐regulates the glucose consumption of carcinoma cells and inhibits the content of intracellular reactive oxygen species (ROS). Therefore, we speculate piRNA‐823 promotes the proliferation, invasion and apoptosis resistance of CRC cells by regulating G6PD/HIF‐1α pathway. In this study, we set up the cancer‐promoting function recovery experiment of piRNA‐823 by silencing G6PD gene to confirm the dominance of the above‐mentioned pathways. Using clinical samples, we found that overexpression of piRNA‐823 correlated with poor overall survival and predicted a poor response to adjuvant chemotherapy of patients with CRC. In a word, our research has further enriched the theory of piRNA‐823 promoting the progression of CRC, and laid a solid foundation for the development of piRNA‐823‐based gene therapy for CRC and its use as a promising prognostic biomarker in CRC patients.

Chaperone-mediated Autophagy Governs Progression of Papillary Thyroid Carcinoma via PPARγ-SDF1/CXCR4 Signaling

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy. Chaperone-mediated autophagy (CMA), 1 type of autophagy, is thought to promote or suppress cancer development in different cancer types. However, the effect of CMA on PTC development and the underlying mechanisms remain unknown. To determine whether CMA plays implied critical roles in the development of PTC. We investigated the association between CMA and PTC development in PTC tissues and normal thyroid tissues by detecting the key protein of CMA, lysosome-associated membrane protein type 2A (LAMP2A), using quantitative polymerase chain reaction (PCR) and immunohistochemistry, which were further validated in the TGCA dataset. The effect of CMA on PTC development was studied by cell proliferation, migration, and apoptosis assays. The underlying mechanisms of peroxisome proliferator-activated receptor γ (PPARγ)-stromal cell-derived factor 1 (SDF1)/ C-X-C motif chemokine receptor 4 (CXCR4) signaling were clarified by western blotting, quantitative PCR, and rescue experiments. Knockdown and tamoxifen were used to analyze the effect of estrogen receptor (ER) α on CMA. Our study confirmed that CMA, indicated by LAMP2A expression, was significantly increased in PTC tumor tissues and cell lines, and was associated with tumor size and lymph node metastasis of patients. Higher CMA in PTC promoted tumor cell proliferation and migration, thereby promoting tumor growth and metastasis. These effects of CMA on PTC were exerted by decreasing PPARγ protein expression to enhance SDF1 and CXCR4 expression. Furthermore, CMA was found positively regulated by ERα signaling in PTC. Our investigation identified CMA regulated by ERα promoting PTC tumor progression that enhanced tumor cell proliferation and migration by targeting PPARγ-SDF1/CXCR4 signaling, representing a potential target for treatment of PTC.

T follicular helper cell-mediated IL-21 production suppresses FOXP3 expression of T follicular regulatory-like cells in diffuse large B cell lymphoma patients

Based on CD25 expression, T follicular helper cells (Tfh) could be divided into T follicular regulatory (Tfr)-like subset (CD25+CD4+CXCR5+) and CD25− Tfh subset (CD25−CD4+CXCR5+). Patients with diffuse large B cell lymphoma (DLBCL) display high level of Tfr-like cells in blood and tumor. This Tfr-like subset could suppress CD8 T cell response while promote tumor cell proliferation. In this study, we investigated the transcription factors and regulatory elements associated with Tfr-like cells in DLBCL patients. Both circulating and tumor-infiltrating Tfr-like cells presented slightly higher Blimp-1 expression and significantly higher Foxp3 expression than the CD25− Tfh subset. As the IL-2 receptor, CD25 could be moderately upregulated in stimulated CD25− Tfh cells. However, stimulated CD25− Tfh cells could not upregulate Foxp3, indicating that the distinction between Foxp3-low CD25−CXCR5+CD4+ T cells and Foxp3-high CD25+CXCR5+CD4+ T cells was not due to differences in stimulation status. Regarding cytokine production, while both Tfr-like and CD25− Tfh cells upregulated IL-21 and IL-10 during stimulation, the CD25− Tfh cells presented significantly higher IL-21 and lower IL-10 expression than the Tfr-like cells, and the TGF-β expression was only increased in Tfr-like cells. Interestingly, IL-21 secreted from CD25− Tfh cells negatively regulated the expression of Foxp3 and IL-10 of autologous Tfr-like cells. Together, these results demonstrated that the Tfr-like and CD25− Tfh subsets of circulating Tfh cells presented different functions and should be investigated separately.

The function of a heterozygous p53 mutation in a Li-Fraumeni syndrome patient.

p53 is one of the most extensively studied proteins in cancer research. Mutations in p53 generally abolish normal p53 function, and some mutants can gain new oncogenic functions. However, the mechanisms underlying p53 mutation-driven cancer remains to be elucidated. Our study investigated the function of a heterozygous p53 mutation (p.Asn268Glufs*4) in a Li-Fraumeni syndrome (LFS) patient. We used episomal technology to perform somatic reprogramming, and used molecular and cell biology methods to determine the p53 mutation levels in patient-originated induced pluripotent stem (iPS) cells at the RNA and protein levels. We found that p53 protein expression was not increased in this patient's somatic cells compared with those of a healthy control. p53 mutation facilitates the proliferation of tumor cells by inhibiting apoptosis and promoting cell division. It can inhibit the efficiency of somatic reprogramming by inhibiting OCT4 expression during reprogramming stage. Moreover, not all p53 mutant iPS cell lines have mutant p53 RNA sequences. A small percentage of mutant p53 mRNA is present in the somatic cells from the patient and his mother. In summary, this p53 mutation can promote tumor cell proliferation, inhibit somatic reprogramming, and exhibit random p53 allelic expression of heterozygous mutations in the patient and iPS cells which may be one of the reasons why the people with p53 mutations develop cancer at random. This finding suggested that mutant p53 allelic expression should be added to the risk forecasting of cancer.

Overexpression of B7‑H4 promotes renal cell carcinoma progression by recruiting tumor‑associated neutrophils via upregulation of CXCL8

The immune checkpoint molecule B7 family member H4 (B7-H4) plays a similar role to programmed death-ligand 1 in tumor immune evasion by regulating T-cell-mediated immune responses. However, besides the role in T-cell immunity, B7-H4 also affects tumor cell biology by promoting tumor cell proliferation, metastasis and angiogenesis. In order to explore the effect of B7-H4 on tumor cell biology, it is necessary to investigate the gene expression profile when B7-H4 is overexpressed. In the present study, 786-O cells were transfected to stably express B7-H4. A microarray technique was subsequently used to screen B7-H4-related differentially expressed genes (DEGs) in B7-H4/786-O cells compared with negative control (NC)/786-O cells. The protein expression of the upregulated DEGs, including non-metastatic cells 5, NME/NM23 family member 5 (NME5), membrane metalloendopeptidase (MME), vascular non-inflammatory molecule 1 (VNN1), matrix metalloproteinase (MMP) 7, tumor necrosis factor, C-X-C motif chemokine ligand (CXCL) 8, CXCL1 and C-C motif chemokine ligand (CCL) 2, was investigated using western blotting. Kidney renal papillary cell carcinoma mRNA-sequencing data obtained from The Cancer Genome Atlas revealed that chemokines, including CXCL1/2/3, CXCL8, MMP7 and CCL20, were positively correlated with B7-H4 gene expression. Furthermore, 59 clinical renal cell carcinoma tissues were collected and analyzed by immunohistochemical staining. The results revealed the positive correlation of B7-H4 with CCL20 and CXCL8, and validated the DEGs identified in tumor cell lines. 786-O transfectants were inoculated into non-obese diabetic/severe combined immunodeficiency mice, and tumor growth was investigated. B7-H4 overexpression promoted tumor growth and administration of anti-CXCL8 antibody reversed this effect. Furthermore, B7-H4 overexpression increased the number of tumor-infiltrating neutrophils while inhibition of CXCL8 abrogated this effect. These data indicated that recruitment of neutrophils in the tumor microenvironment by CXCL8 serves an important role in the tumor promotion effect of B7-H4. The present study revealed a novel mechanism of B7-H4 in tumor promotion in addition to T cell inhibition.

Beyond Cell Motility: The Expanding Roles of Chemokines and Their Receptors in Malignancy.

The anti-tumor activities of some members of the chemokine family are often overcome by the functions of many chemokines that are strongly and causatively linked with increased tumor progression. Being key leukocyte attractants, chemokines promote the presence of inflammatory pro-tumor myeloid cells and immune-suppressive cells in tumors and metastases. In parallel, chemokines elevate additional pro-cancerous processes that depend on cell motility: endothelial cell migration (angiogenesis), recruitment of mesenchymal stem cells (MSCs) and site-specific metastasis. However, the array of chemokine activities in cancer expands beyond such “typical” migration-related processes and includes chemokine-induced/mediated atypical functions that do not activate directly motility processes; these non-conventional chemokine functions provide the tumor cells with new sets of detrimental tools. Within this scope, this review article addresses the roles of chemokines and their receptors at atypical levels that are exerted on the cancer cell themselves: promoting tumor cell proliferation and survival; controlling tumor cell senescence; enriching tumors with cancer stem cells; inducing metastasis-related functions such as epithelial-to-mesenchymal transition (EMT) and elevated expression of matrix metalloproteinases (MMPs); and promoting resistance to chemotherapy and to endocrine therapy. The review also describes atypical effects of chemokines at the tumor microenvironment: their ability to up-regulate/stabilize the expression of inhibitory immune checkpoints and to reduce the efficacy of their blockade; to induce bone remodeling and elevate osteoclastogenesis/bone resorption; and to mediate tumor-stromal interactions that promote cancer progression. To illustrate this expanding array of atypical chemokine activities at the cancer setting, the review focuses on major metastasis-promoting inflammatory chemokines—including CXCL8 (IL-8), CCL2 (MCP-1), and CCL5 (RANTES)—and their receptors. In addition, non-conventional activities of CXCL12 which is a key regulator of tumor progression, and its CXCR4 receptor are described, alongside with the other CXCL12-binding receptor CXCR7 (RDC1). CXCR7, a member of the subgroup of atypical chemokine receptors (ACKRs) known also as ACKR3, opens the gate for discussion of atypical activities of additional ACKRs in cancer: ACKR1 (DARC, Duffy), ACKR2 (D6), and ACKR4 (CCRL1). The mechanisms involved in chemokine activities and the signals delivered by their receptors are described, and the clinical implications of these findings are discussed.

SHCBP1 promotes tumor cell proliferation, migration, and invasion, and is associated with poor prostate cancer prognosis.

Prostate cancer (PCa) is an aggressive tumor. SHC SH2-domain-binding protein 1 (SHCBP1) has been identified frequently upregulated in various cancers, in addition to PCa. The aims of this study were to determine the relationships between SHCBP1 and clinicopathological characteristics of PCa and to explore the role of SHCBP1 in PCa proliferation and progression. Tissue microarray and immunohistochemistry were used to determine the prognostic significance of SHCBP1. The relationship between clinicopathological characteristics of PCa and SHCBP1 was then analyzed using Cox regression analyses. To investigate SHCBP1 functions in vitro and in vivo, we knocked down SHCBP1 in PCa cell lines and established xenograft mice models. A series of cytological function assays were utilized to determine the role of SHCBP1 in cell proliferation, migration, invasion, and apoptosis. SHCBP1 was significantly upregulated in PCa tissues compared with BPH tissues. Patients with a higher expression of SHCBP1 were associated with poor survival outcomes than those with a lower expression of SHCBP1. Lentivirus-mediated shRNA knockdown of SHCBP1 in prostate cancer cell lines diminished cell growth, migration, and invasion dramatically both in vitro and in vivo, accompanied by an enhanced expression of large tumor suppressor 1 (LATS1) and tumor protein P53 (TP53) and inhibition of MDM2 proto-oncogene (MDM2), which suggested that SHCBP1 may promote proliferation and invasion in vitro via the LATS1-MDM2-TP53 pathway. The results of cycloheximide (CHX) and MG-132 assays indicated that SHCBP1 knockdown could attenuate the degradation of TP53 by the proteasome, prolong the half-life of TP53, and enhance the stabilization of TP53. These findings suggest that SHCBP1 overexpression contributes to PCa progression and that targeting SHCBP1 might be therapeutically beneficial to patients with PCa.

Polycomb-like 2 regulates PRC2 components to affect proliferation in glioma cells

IntroductionThe Polycomb group (PcG) is an important family of transcriptional regulators that controls growth and tumorigenesis. The PcG mainly consists of two complexes, PRC1 and Polycomb Repressive Complex 2 (PRC2). Polycomb-like 2 (PCL2) is known to interact with the PRC2 protein. The role of PCL2 in the development and progression of glioma is unclear.MethodsWe use The Cancer Genome Atlas (TCGA) database to detect the expression of PCL2 in various tumors. 117 cases of clinical glioma (WHOI–IV) were collected, and PCL2 expression and localization were detected by immunohistochemical staining. Glioma cells U87/U251 were infected with overexpressed and interfered PCL2. CCK8 assay, colony formation assay, EdU method, cell cycle and apoptosis were used to detect cell proliferation and apoptosis. Western blot was used to detect the expression of PRC2-related core proteins. After DZNeP intervention, PRC2 protein expression was again measured to discuss the mechanism of PCL2 action.ResultsTCGA database results and immunohistochemical staining results suggest that PCL2 is highly expressed in gliomas. We found that the PCL2 gene promoted tumor cell proliferation, enhanced the colony formation ability, and increased S phase in the cell cycle. The overexpression of PCL2 upregulated the expression levels of EZH2 and EED (two core members of PRC2), decreased the expression of SUZ12, increased the level of H3K27 trimethylation (H3K27me3), H3K4 dimethylation (H3K4me2), and decreased H3K9 dimethylation (H3K9me2). The result after interfering with PCL2 was the opposite.ConclusionsAs an important accessory protein of PRC2, PCL2 can not only change the expression of PRC2 components, but also affect the expression level of Histone methylation. Therefore, PCL2 may be an important hub for regulating the synergy among PRC2 members. This study revealed PCL2 as a new target for tumor research and open up a new avenue for future research in glioma.

Deciphering the Roles of IFITM1 in Tumors.

Interferon (IFN)-induced transmembrane protein 1 (IFITM1), a member of the IFN-induced transmembrane protein family, is reported to be highly expressed in tumor tissues as well as cancer cell lines, and it is an independent prognostic biomarker for patients with certain tumor types, such as gallbladder carcinoma, esophageal adenocarcinoma, colorectal cancer, and gastric cancer. Moreover, overexpression of IFITM1 promotes tumor cell proliferation, invasion, metastasis, angiogenesis, and therapeutic resistance, including endocrine therapy, chemotherapy, and radiotherapy resistance. Due to these diverse functions of IFITM1 in tumors, targeting IFITM1 may provide a novel strategy for cancer treatment and be highly desirable to improve cancer patient outcomes. Herein, we decipher the role of IFITM1 in cancer in detail.

Aberrant Expression of Syndecan-1 in Cervical Cancers

Syndecan-1, is a transmembrane heparan/chondroitin sulfate proteoglycan necessary for cell-cell and cell-matrix interactions. Its decreased level on the cell surface correlates with poor prognosis in several tumor types. Aberrant stromal localization of syndecan-1 is also considered an unfavorable prognostic factor in various human malignancies. In the presented work the question was addressed if changes in syndecan-1 expression are related to the prognosis of cervical cancer. Immunohistochemistry for syndecan-1 extracellular domain was performed on surgical specimens of primary cervical cancer. To follow the communication between tumor cells and stromal fibroblasts, their mono-and co-cultures were studied, detecting the expression of syndecan-1, smooth muscle actin, vimentin, and desmin. Immunohistochemistry of tumorous specimens revealed that while cell surface syndecan-1 expression was reduced on cancer cells, it appeared on the surface of tumor-associated fibroblasts. Until year 7, the cohort with high cell surface syndecan-1 expression had significantly longer survival. No difference in the same time-period could be detected when stromal syndecan-1 expression was analyzed. In vitro analysis revealed, that tumor cells can induce syndecan-1 expression on fibroblast, and fibroblasts showed that fibroblast-like cells are built by two cell types: (a) syndecan-1 positive, cytokeratin negative real fibroblasts, and (b) syndecan-1 and cytokeratin positive epithelial-mesenchymal transformed tumor cells. Syndecan-1 on the surface of cancer cells appears to be a positive prognostic marker. Although syndecan-1 positive fibroblasts promote tumor cell proliferation in vitro, we failed to detect their cancer promoting effect in vivo.

NT5DC2 promotes tumor cell proliferation by stabilizing EGFR in hepatocellular carcinoma

Most hepatocellular carcinoma (HCC) patients are diagnosed at an advanced stage; however, the effect of systemic therapy on advanced HCC remains undetermined. Therefore, new treatment targets must be identified. We analyzed Gene Expression Omnibus datasets from two HCC patient cohorts and found that NT5DC2 was associated with vascular invasion and poor survival. In two hepatoma cell lines, NT5DC2 overexpression promoted HCC cell proliferation and clone formation in vitro and promoted tumor growth in vivo. Coimmunoprecipitation assays and liquid chromatography with tandem mass spectrometry analysis revealed that NT5DC2 bound directly to epidermal growth factor receptor (EGFR). NT5DC2 upregulated EGFR expression by downregulating EGFR ubiquitination and preventing its degradation via the ubiquitin-proteasome pathway but did not upregulate its transcription. EGFR upregulation activated downstream signal transduction, which played a critical role in the protumor effects of NT5DC2. Erlotinib, a small-molecule inhibitor of EGFR, blocked the effect of NT5DC2 in promoting HCC cell proliferation. In a cohort of 79 patients who underwent curative resection for HCC, NT5DC2 expression in the tumors was associated with larger tumors and microvascular invasion. NT5DC2 expression was also independently associated with recurrence-free survival. The present study demonstrated for the first time that NT5DC2 promotes tumor cell proliferation in HCC and may serve as a potential molecular target for treating HCC. EGFR blockage could be used to treat selected patients with NT5DC2 upregulation.

Immunohistochemical Expression of “L1 cell Adhesion Molecule” in Endometrial Carcinomas

BACKGROUND: Endometrial cancer is the most common cancer of the female genital tract. No effective biomarkers currently exist to allow for an efficient risk classification of endometrial carcinoma or to direct treatment (adjuvant radiation and/or chemotherapy) or to triage pelvic and para-aortic lymphadenectomy. L1 cell adhesion molecule (L1CAM) a transmembrane protein of the immunoglobulin family that has been implicated in promoting tumor cell proliferation, migration, invasion, and metastasis became an attractive candidate as a potential biomarker in endometrial carcinoma and potential therapeutic target in high-risk groups.
 OBJECTIVES: Evaluation of L1CAM expression in endometrial carcinoma and correlation of this expression with various pathological parameters.
 MATERIALS AND METHODS: Immunohistochemical staining for L1CAM was performed on paraffin-embedded sections of 80 cases of endometrial carcinomas that underwent total hysterectomy with bilateral salpingo-oophorectomy. Expression of L1CAM in >10% of tumor cells was interpreted as positive.
 RESULTS: L1CAM expression was detected in 22.5% of cases and showed statistically significant correlation with non-endometrioid histological type, high grade, high FIGO stage, high pathological (T) stage, cervical involvement, nodal metastasis, lymphovascular space invasion, and high-risk tumor according to the European Society for Medical Oncology system for risk stratification (p < 0.05).
 CONCLUSION: The high rate of L1CAM expression in high-risk endometrial carcinomas suggests that L1CAM represents a potential marker for the identification of patients needing closer follow-up and aggressive treatment. In addition, its potential role as a therapeutic target for high-risk endometrial cancer seems promising.

Germline APOBEC3B deletion influences clinicopathological parameters in luminal-A breast cancer: evidences from a southern Brazilian cohort.

APOBEC3A and APOBEC3B cytidine deaminases have been implicated in the pathogenesis of multiple cancers, including breast cancer (BC). A germline deletion linking APOBEC3A and APOBEC3B loci (A3A/B) has been associated with higher APOBEC-mediated mutational burden, but its association with BC risk have been controversial. Therefore, this study investigated the association between A3A/B and BC susceptibility and clinical presentation in a Brazilian cohort. A3A/B deletion was evaluated through allele-specific PCR in 341 BC patients and 397 women without familial or personal history of neoplasia from Brazil and associations with susceptibility to BC subtypes were tested through age-adjusted logistic models while correlations with clinicopathological parameters were tested using Kendall's tests. No association was found between A3A/B and BC susceptibility; however, in Luminal-A BCs, it was positively correlated with tumor size (Tau-c = 0.125) and Ki67 (Tau-c = 0.116) and negatively correlated with lymph node metastasis (LNM) (Tau-c = -0.162). The negative association between A3A/B with LNM in Luminal-A BCs remained significant even after adjusting for tumor size and Ki67 in logistic models (OR = 0.22; p = 0.008). These results show that although A3A/B may not modify BC susceptibility in Brazilian population, it may affect clinicopathological features in BC subtypes, promoting tumor cell proliferation while being negatively associated with LNM in Luminal-A BCs.

FSTL3 Promotes Tumor Cell Proliferation, Invasion, Survival and Associates with Poor Prognosis in Colorectal Cancer Patients

Follistatin like‐3 (FSTL3) is a potent inhibitor that antagonizes TGF‐β family ligands including activin, myostatin and bone morphogenetic proteins. Though usually a secreted glycoprotein, nuclear FSTL3 expression had been noted in several cell types, suggesting the existence of specific intracellular functions of this protein. Colorectal cancer (CRC) is one of the leading malignant tumors worldwide. Its strong metastatic ability and chemoresistance tendency is a major obstacle in clinical treatment. In large cohort survival analyses, we have found that FSTL3 has a significant prognostic predictive power in colorectal cancer at both RNA and protein level. Immunohistochemistry staining of CRC specimens revealed that patients with high FSTL3 expression are significantly associated with poor survival. Our study further showed that knockdown of FSTL3 inhibited the migration and invasion of colon cancer cells and reduced tumorigenesis in vivo. Conversely, ectopic over‐expression of FSTL3 elicited the opposite effects in CRC cells. In addition, the overexpression of FSTL3 was found to confer the resistance to 5‐fluorouracil in CRC cells. mRNA profiling analyses suggested that FSTL3 drives CRC tumorigenesis through various carcinogenesis‐related pathways. Our results unveil the significance of FSTL3 in the oncogenesis of CRC, with implications for its potential use as a diagnostic or prognostic biomarker and also a candidate for therapeutic target in this disease.Support or Funding InformationThis research was supported by Academia Sinica [AS‐SUMMIT‐108].

Knockdown and Inhibition of SYK Tyrosine Kinase Decreases mTORC1 Activity and Enhances Lysosomal Biogenesis and Autolysosomal Maturation in Pancreatic Cancer Cell Lines

In cancer, oncogene dependency is a phenomenon where a dominant driver oncogene promotes tumor cell proliferation and survival, and loss of this oncogene results in tumor cell death and, eventually, tumor regression. KRAS, a GTPase that regulates cell growth and proliferation, is an oncogene constitutively activated in over 90% of pancreatic cancer. However, clinically effective inhibitors of KRAS have been unsuccessful so efforts have been focused on identifying other potential targets associated with the KRAS signaling network. Spleen tyrosine kinase (SYK), expressed at high levels in KRAS‐dependent pancreatic cancer cell lines, may be one of these targets. Our data indicate that SYK activates the mechanistic target of rapamycin kinase complex 1 (mTORC1), which promotes protein translation and cell growth. SYK activation also leads to decreased autolysosome count. In connecting SYK activation with increase mTORC1 activity and decrease autolysosome count, we hypothesis that the MiT/TFE transcription factors are involved. We propose that SYK inhibition in pancreatic cancer cells leads to reduced mTORC1 activity, which reduces phosphorylation of MiT/TFE transcription factors. The unphosphorylated MiT/TFE transcription factors are then allowed into the nucleus to activate genes for lysosomal biogenesis and autophagy. Autophagy is a process that recycles cellular macromolecules during nutrient deprivation by fusing autophagosomes and lysosomes, produced from lysosomal biogenesis, to generate autolysosomes. From our experiments, we were able to show that SYK inhibition blocks mTORC1‐dependent phosphorylation of MITF and TFEB transcription factors, members of the MiT/TFE family. MITF and TFEB activation leads to increased autophagy due to autolysosomal biogenesis and accumulation. In summary, our studies of the SYK‐mTORC1‐autophagy pathway provide support to investigate SYK as a candidate, therapeutic target for pancreatic cancer treatment.Support or Funding InformationNIH/NCI K99/R00 ‐ Anurag Singh (PI); Boston University Dahod Breast Cancer Pilot Award ‐ Anurag Singh (PI); Boston University's Undergraduate Research Opportunities Program ‐ Michelle Pan

TGFβ and Hippo Pathways Cooperate to Enhance Sarcomagenesis and Metastasis through the Hyaluronan-Mediated Motility Receptor (HMMR).

High-grade sarcomas are metastatic and pose a serious threat to patient survival. Undifferentiated pleomorphic sarcoma (UPS) is a particularly dangerous and relatively common sarcoma subtype diagnosed in adults. UPS contains large quantities of extracellular matrix (ECM) including hyaluronic acid (HA), which is linked to metastatic potential. Consistent with these observations, expression of the HA receptor, hyaluronan-mediated motility receptor (HMMR/RHAMM), is tightly controlled in normal tissues and upregulated in UPS. Moreover, HMMR expression correlates with poor clinical outcome in these patients. Deregulation of the tumor-suppressive Hippo pathway is also linked to poor outcome in these patients. YAP1, the transcriptional regulator and central effector of Hippo pathway, is aberrantly stabilized in UPS and was recently shown to control RHAMM expression in breast cancer cells. Interestingly, both YAP1 and RHAMM are linked to TGFβ signaling. Therefore, we investigated crosstalk between YAP1 and TGFβ resulting in enhanced RHAMM-mediated cell migration and invasion. We observed that HMMR expression is under the control of both YAP1 and TGFβ and can be effectively targeted with small-molecule approaches that inhibit these pathways. Furthermore, we found that RHAMM expression promotes tumor cell proliferation and migration/invasion. To test these observations in a robust and quantifiable in vivo system, we developed a zebrafish xenograft assay of metastasis, which is complimentary to our murine studies. Importantly, pharmacologic inhibition of the TGFβ-YAP1-RHAMM axis prevents vascular migration of tumor cells to distant sites. IMPLICATIONS: These studies reveal key metastatic signaling mechanisms and highlight potential approaches to prevent metastatic dissemination in UPS.YAP1 and TGFβ cooperatively enhance proliferation and migration/invasion of UPS and fibrosarcomas.

MicroRNA‑28 promotes the proliferation of non‑small‑cell lung cancer cells by targeting PTEN.

Non-small-cell lung cancer (NSCLC) is the fundamental form of lung cancer and the leading cause of cancer‑related mortality in humans. Numerous studies have identified a role for microRNAs (miRs) in cell proliferation, invasion and metastasis in numerous types of cancer, including lung cancer. In the present study, the functional roles and molecular mechanisms of miR‑28 in NSCLC tumorigenesis were investigated. Reverse transcription‑quantitative PCR (RT‑qPCR) was used to measure miR‑28 expression levels in NSCLC tumor tissues and cell lines. A dual‑luciferase assay was performed to observe the direct interaction between miR‑28 and PTEN in A549cells. Furthermore, the effect of miR‑28 on the mRNA and protein expression levels of PTEN was examined by RT‑qPCR and western blotting, respectively. A Cell Counting kit‑8 assay was performed to identify the relationship between the miR‑28/PTEN axis and tumor cell proliferation using cells infected with lentivirus (LV)‑anti‑miR‑28 or LV‑anti‑miR‑28+short hairpin RNA‑PTEN. miR‑28 expression was upregulated in NSCLC tumor tissues and cell lines compared with the control groups. PTEN was identified as the downstream gene of miR‑28 in NSCLC and was negatively regulated by miR‑28. In addition, miR‑28 knockdown suppressed the proliferation of A549 and H292cells. Cells infected with LV‑anti‑miR‑28+short hairpin RNA‑PTEN promoted tumor cell proliferation in A549 and H292cells compared with cells infected with LV‑anti‑miR‑28. Taken together, the present study suggested that miR‑28 might serve as the promoter in the development of NSCLC by targeting PTEN. Therefore, the miR‑28/PTEN axis may serve as a potential diagnostic and therapeutic target for NSCLC.

Signal Transduction Pathways in Breast Cancer: The Important Role of PI3K/Akt/mTOR.

Breast cancer is the cancer with the highest prevalence in women and is the number-one cause of cancer mortality worldwide. Cell transduction is a fundamental process in the development and progression of cancer. Modifications in various cell signalling pathways promote tumour cell proliferation, progression, and survival. The PI3K/Akt/mTOR pathway is an example of that, and it is involved in growth, proliferation, survival, motility, metabolism, and immune response regulation. Activation of this pathway is one of the main causes of cancer cell resistance to antitumour therapies. This makes PI3K/Akt/mTOR signalling a crucial object of study for understanding the development and progression of this disease. Thus, this pathway may have a role as a potential therapeutic target, as well as prognostic and diagnostic value, in patients with breast cancer. Despite the existence of selective PI3K/Akt/mTOR pathway inhibitors and current clinical trials, the cellular mechanisms are not yet known. The present review aims to understand the current state of this important disease and the paths that must be forged.