Accumulating evidence shows that microRNA-217 (miR-217) is frequently dysregulated in various cancers, and plays crucial roles in tumorigenesis and metastasis; however, the role and underlying molecular mechanism of miR-217 in human epithelial ovarian cancer (EOC) remains unclear. Here, we report that miR-217 expression was downregulated in EOC tissue and inversely correlated with advanced FIGO stage, high histological grading and lymph node metastasis (P<0.01). Function analysis revealed that the ectopic expression of miR-217 in EOC cells inhibited cell proliferation, migration and invasion in vitro, as well as suppressed tumor growth in vivo. Bioinformatics analysis and dual luciferase assays identified insulin-like growth factor 1 receptor (IGF1R) as a direct target of miR-217 in EOC cells. Western blot assay showed that overexpression of miR-217 in EOC cells inhibited IGF1R expression. In addition, downregulation of IGF1R mimicked the tumor-suppressive effects of miR-217 in EOC cells, whereas the reintroduction of IGF1R partially abrogated the suppression effect induced by miR-217 on EOC cells. Collectively, these results demonstrated that miR-217 plays a tumor suppressor role in human epithelial ovarian cancer by directly targeting IGF1R gene, suggesting a new potential therapeutic target in EOC.

T-Cell acute lymphoblastic leukemia is considered a largely curable disease in children; however, adult patients and children with refractory or relapsed disease have consistently poor outcomes. On the basis of our prior work highlighting CD44 as a marker of leukemia-initiating cells in animal models and because cancer stem cells are postulated to possess intrinsic resistance to conventional chemotherapy, we examined whether CD44 itself might play a role in mediating chemoresistance. We report here that in both genetically defined mouse models and human cell lines, CD44 expression is associated with chemoresistance, and that this effect is mediated in part through enhanced drug efflux. Interestingly, we also observed increased CD44 expression in residual blasts following standard induction chemotherapy, as compared with blasts from matched, pretherapy samples in a subset of pediatric patients undergoing minimal residual disease monitoring as part of a clinical trial. These findings support a functional role for CD44 in promoting chemotherapy resistance and suggest that targeting it directly or its relevant effector pathways may improve clinical responses in T-cell acute lymphoblastic leukemia.

MG-63 human osteosarcoma cells were transfected with short hairpin RNA (shRNA) against livin and survivin using monomethoxypolyethylene glycol‑chitosan (mPEG‑CS) nanoparticles (NPs) as carriers, with the aim of evaluating the effect on cell proliferation and apoptosis. mPEG‑CS NPs sized ~100 nm were prepared by ionic crosslinking. mPEG‑CS‑livin shRNA, mPEG‑CS‑survivin shRNA and mPEG‑CS‑(livin shRNA + survivin shRNA) NPs were constructed by electrostatic adsorption at NP suspension/gene solution ratios of 3:1 to transfect MG‑63 cells. The expression levels of livin and survivin mRNA and protein were measured by reverse transcription‑polymerase chain reaction and western blotting, respectively. The inhibitory effects of downregulated livin and survivin expression on cell proliferation were measured using an MTT assay. The apoptosis‑inducing effects of livin and surivin knockdown were investigated using a Hoechst staining kit. All shRNA groups resulted in reduced expression of livin and survivin mRNA and protein in MG‑63 cells. The MTT assay and Hoechst staining indicated that simultaneous knockdown of livin and survivin genes inhibited the proliferation of MG‑63 cells and promoted their apoptosis, to a greater extent than knocking down either gene individually. The simultaneous interference mediated by mPEG‑CS NPs significantly reduced livin and survivin expression in MG‑63 cells, suppressed proliferation and facilitated apoptosis, to a greater extent than knockdown of either livin or survivin alone were. Thus the results indicate a synergistic effect of livin and survivin.

Autophagy has been recognized as an important element of tumor cell migration, invasion, and chemo-resistance, and our previous results showed that Beclin-1-mediated autophagy contributed to osteosarcoma chemoresistance. However, the regulating mechanism of autophagy is still unclear. In this study, our aim was to clarify microRNA (miRNA)-related mechanisms underlying Beclin-1-mediated autophagy followed by chemotherapy in osteosarcoma. First, miRNA screening using qRT-PCR identified that miR-30a was significantly reduced in Dox-resistant osteosarcoma cells. Second, the autophagy activity in Dox-resistant increased while miR-30a expression reduced after chemotherapy agents as indicated by the enhanced expression of Beclin-1, the increased conversion of microtubule-associated protein LC3-I to LC3-II. Furthermore, overexpression of miR-30a significantly promoted chemotherapy-induced apoptosis and reduced autophagy activity responding to chemotherapy. Moreover, rapamycin, an autophagy promoter was able to partly reverse the effect of miR-30a and Luciferase reporter assay identified that miR-30a directly binds to the 3'-UTR of Beclin-1 gene, which further confirmed that miR-30a reduced chemoresistance via suppressing Beclin-1-mediated autophagy. Collectively these results indicate miR-30a and its downstream target gene Beclin-1 can be used in treatment of osteosarcoma chemo-resistance in the future.

Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults and is associated with a poor prognosis due to a lack of early‑warning signs, protean clinical manifestations, and resistance to radiotherapy and chemotherapy. Recently, increasing evidence has suggested that microRNAs (miRNAs) are involved in the proliferation, invasion and apoptosis of various types of human cancer cells. In a previous study, miRNA expression profiles from renal cell carcinoma (RCC) revealed that expression of miR‑20b‑5p was significantly downregulated in RCC tissues. The aim of this study was to investigate the expression and functional significance of miR‑20b‑5p in RCC. The expression of miR‑20b‑5p was quantified in 48 paired RCC tissues and cell lines, and compared with adjacent normal tissues and the 293T cell line by reverse transcription‑quantitative polymerase chain reaction. The functional impact of miR‑20b‑5p on cell proliferation, cell migration and apoptosis in the 786‑O and ACHN RCC cell lines, was determined by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, a scratch assay and flow cytometry. To the best of our knowledge, the present study was the first to reveal that miR‑20b‑5p was downregulated in RCC tissues and cell lines. It also demonstrated that upregulation of miR‑20b‑5p inhibited cellular migration and proliferation, and promoted cellular apoptosis, suggesting that miR‑20b‑5p functioned as a potential tumor suppressor. However, further studies are required to fully determine the effects of miR‑20b‑5p and the miR‑20b‑5p‑mediated molecular pathway in RCC and other types of cancer. In conclusion, these results imply that miR‑20b‑5p may be a biomarker for early detection and prognosis prediction, as well as a therapeutic target for RCC.

Glioblastoma (GBM) is the most common malignant brain tumor in adults. We designed an adeno-associated virus (AAV) vector for intracranial delivery of secreted, soluble tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL) to GBM tumors in mice and combined it with the TRAIL-sensitizing cardiac glycoside, lanatoside C (lan C). We applied this combined therapy to two different GBM models using human U87 glioma cells and primary patient-derived GBM neural spheres in culture and in orthotopic GBM xenograft models in mice. In U87 cells, conditioned medium from AAV2-sTRAIL expressing cells combined with lan C induced 80% cell death. Similarly, lan C sensitized primary GBM spheres to sTRAIL causing over 90% cell death. In mice bearing intracranial U87 tumors treated with AAVrh.8-sTRAIL, administration of lan C caused a decrease in tumor-associated Fluc signal, while tumor size increased within days of stopping the treatment. Another round of lan C treatment re-sensitized GBM tumor to sTRAIL-induced cell death. AAVrh.8-sTRAIL treatment alone and combined with lanatoside C resulted in a significant decrease in tumor growth and longer survival of mice bearing orthotopic invasive GBM brain tumors. In summary, AAV-sTRAIL combined with lanatoside C induced cell death in U87 glioma cells and patient-derived GBM neural spheres in culture and in vivo leading to an increased in overall mice survival.

Colorectal cancer (CRC) is a leading cause of death in the United States. Despite its slow development and the capacity for early diagnosis, current preventive approaches are not sufficient. However, a role for estrogen has been demonstrated in multiple epidemiologic studies, which may benefit CRC prevention. A large body of evidence from preclinical studies indicates that expression of the estrogen receptor beta (ERβ/ESR2) demonstrates an inverse relationship with the presence of colorectal polyps and stage of tumors, and can mediate a protective response. Natural compounds, including phytoestrogens, or synthetic ERβ selective agonists, can activate or upregulate ERβ in the colon and promote apoptosis in preclinical models and in clinical experience. Importantly, this activity has been associated with a reduction in polyp formation and, in rodent models of CRC, has been shown to lower incidence of colon adenocarcinoma. Collectively, these findings indicate that targeted activation of ERβ may represent a novel clinical approach for management of colorectal adenomatous polyps and prevention of colorectal carcinoma in patients at risk for this condition. In this review, we discuss the potential of new chemopreventive or dietary approaches based on estrogen signaling.

Long non-coding RNAs (lncRNAs) are important regulators in pathological processes, yet their potential roles in pancreatic ductal adenocarcinoma (PDAC) are poorly understood. Here, we found that a novel lncRNA, LOC389641, was upregulated in PDAC tissues and cell lines. The expression of LOC389641 was significantly correlated with staging, lymph node metastasis and overall survival. Knockdown of LOC389641 impaired cell proliferation and invasion and induced cell apoptosis in vitro, whereas overexpression of LOC389641 had the opposite effect. The growth promoting effect of LOC389641 was also demonstrated in vivo. Further, a significant negative correlation was observed between E-cadherin levels and LOC389641 levels in vivo. Knockdown of LOC389641 upregulated E-cadherin expression, but knockdown of E-cadherin had a limited influence on LOC389641. Importantly, after E-cadherin was inhibited, the enhancement of LOC389641 on cell invasion was hindered. Moreover, the expression of LOC389641 was closely associated with its genomic neighboring gene TNFRSF10A. Lastly, knockdown experiments showed that TNFRSF10A might be a connection between LOC389641and E-cadherin. We conclude that LOC389641 promotes PDAC progression and increases cell invasion by regulating E-cadherin with the possible involvement of TNFRSF10A.

Radiotherapy resistance is the main cause of the the poor prognosis of some nasopharyngeal carcinoma (NPC) patients. Yet, the exact mechanism is still elusive. In the present study, we explored the clinical and biological role of protein arginine methyltransferase 5 (PRMT5) in NPC. Our results revealed that PRMT5 was overexpressed in NPC tissues when compared with that in adjacent non-tumor tissues by quantitative RT-PCR and immunoblotting. High expression of PRMT5 was correlated with adverse outcomes of NPC patients as determined by the scoring of a tissue microarray. Silencing of PRMT5 promoted the radiosensitivity of 5-8F and CNE2 cells as determined by cell proliferation and colony formation assays. Furthermore, fibroblast growth factor receptor 3 (FGFR3) was identified as one of the downstream targets of PRMT5, and the silencing of PRMT5 decreased the mRNA and protein levels of FGFR3 in the 5-8F and CNE2 cells. Silencing of FGFR3 induced similar phenotypes as the inhibition of PRMT5, and re-expression of FGFR3 in 5-8F/shPRMT5 and CNE2/shPRMT5 cells restored the proliferation and colony formation ability induced by irradiation exposure. Our results indicate that PRMT5 is a marker of poor prognosis in NPC patients. PRMT5 promoted the radioresistance of NPC cells via targeting FGFR3, at least partly if not totally. PRMT5 and its downstream effector FGFR3 may be potential targets for anticancer strategy.

Osteosarcoma (OS) is the most common primary bone cancer, and it is most prevalent in children and young adults. The prognosis of OS remains poor, and survival of OS reached a plateau. The discovery of microRNAs (miRNAs) provides a new possibility for the early diagnosis and treatment of OS. In this study, we detected the expression level of miR-205 and Transforming growth factor-alpha (TGF-α) in 15 cases of clinical OS tissues and adjacent normal bone tissues. We found that the expression of miR-205 was significantly lower in OS tissues than in normal bone tissues; the expression of TGF-α mRNA was significantly increased in OS tissues than in normal bone tissues, the miR-205 was negatively correlated with TGF-α levels in both OS and normal bone tissues. Functional studies demonstrated that miR-205 significantly decreased the capability of cell proliferation, invasion and migration and induced G0/G1 growth arrest and apoptosis in OS cells. By using bioinformatics analytic tool (Targetscan), the 3'UTR of TGF-α gene was found to be a target of miR-205. Luciferase report assay further confirmed that TGF-α 3'UTR is a direct target of miR-205. We also found that the expression of TGF-α mRNA and protein was significantly down-regulated or up-regulated after miR-205 mimic or miR-205 inhibitor transfection. TGF-α knockdown study further showed that miR-205 regulated cell proliferation, invasion and migration by targeting TGF-α in OS. Enforced expression of TGF-α sufficiently restore the effects of miR-205 on cell proliferation, invasion and migration. In conclusion, our study suggested that miR-205 may function as a tumor suppressor via targeting TGF-α in OS, and the abnormal expression of miR-205 might be a key factor in OS progression.

The study aims to uncover molecular mechanisms of PTC (papillary thyroid carcinoma) progression and provide therapeutic biomarkers.

The single-stranded nucleic acid-binding protein KHSRP (KH-type splicing regulatory protein) modulates RNA life and gene expression at various levels. KHSRP controls important cellular functions as different as proliferation, differentiation, metabolism, and response to infectious agents. We summarize and discuss experimental evidence providing a potential link between changes in KHSRP expression/function and human diseases including neuromuscular disorders, obesity, type II diabetes, and cancer.

Recent studies suggest that metformin, which is a commonly used oral anti-hyperglycemic agent of the biguanide family, may reduce cancer risk and improve prognosis, yet the detailed mechanisms by which metformin affects various types of cancers, including pancreatic cancer, remain unknown. The aim of the present study was to evaluate the effects of metformin on human pancreatic cancer cell proliferation in vitro and in vivo, and to study microRNAs (miRNAs) associated with the antitumor effect of metformin. We used the human pancreatic cancer cell lines Panc1, PK1 and PK9 to study the effects of metformin on human pancreatic cancer cells. Athymic nude mice bearing xenograft tumors were treated with or without metformin. Tumor growth was recorded after 5 weeks, and the expression of cell cycle-related proteins was determined. In addition, we used miRNA microarray tips to explore the differences in the levels of miRNAs in Panc1 cells and xenograft tumors treated with metformin or without. Metformin inhibited the proliferation of Panc1, PK1 and PK9 cells in vitro. This inhibition was accompanied by a strong decrease in G1 cyclins (particularly in cyclin D1) and retinoblastoma protein (Rb) phosphorylation. In addition, metformin reduced the phosphorylation of epidermal growth factor receptor (EGFR), particularly the phosphorylation of EGFR at Tyr845, and insulin-like growth factor 1 receptor (IGF-1R) in vitro and in vivo. miRNA expression was markedly altered by the treatment with metformin in vitro and in vivo. Our results revealed that metformin inhibits human pancreatic cancer cell proliferation and tumor growth, possibly by suppressing the cell cycle-related molecules via alteration of miRNAs.

RNA-sequencing of a splenic hemangioma with the karyotype 45~47,XX,t(3;6)(q26;p21) showed that this translocation generated a chimeric TBL1XR1-HMGA1 gene. This is the first time that this tumor has been subjected to genetic analysis, but the finding of an acquired clonal chromosome abnormality in cells cultured from the lesion and the presence of the TBL1XR1-HMGA1 fusion in them strongly favor the conclusion that splenic hemangiomas are of a neoplastic nature. Genomic PCR confirmed the presence of the TBL1XR1-HMGA1 fusion gene, and RT-PCR together with Sanger sequencing verified the presence of the fusion transcripts. The molecular consequences of the t(3;6) would be substantial. The cells carrying the translocation would retain only one functional copy of the wild-type TBL1XR1 gene while the other, rearranged allele could produce a putative truncated form of TBL1XR1 protein containing the LiSH and F-box-like domains. In the TBL1XR1-HMGA1 fusion transcript, furthermore, untranslated exons of HMGA1 are replaced by the first 5 exons of the TBL1XR1 gene. The result is that the entire coding region of HMGA1 comes under the control of the TBL1XR1 promoter, bringing about dysregulation of HMGA1. This is reminiscent of similar pathogenetic mechanisms involving high mobility genes in benign connective tissue tumors such as lipomas and leiomyomas.

The purpose of the present study was to explore the role and mechanism of extracellular ecto-5'-nucleotidase (CD73) in human colorectal cancer growth. Firstly, CD73 expression was detected in colorectal cancer cell lines both at the mRNA and protein levels. Secondly, recombinant CD73 interference and overexpression lentiviruses were used, respectively. Colony formation assay, CCK-8 assay and flow cytometry were used to investigate the impact of CD73 on colorectal cancer cell proliferation and cell cycle distribution. Then, adenosine and CD73 enzyme activity inhibitor (APCP) were used to study the effect of CD73 on Epidermal growth factor receptor (EGFR) and β-catenin/cyclin D1 signaling pathways. Finally, a human colorectal cancer transplantation nude mouse model was used to observe the effect of CD73 on tumor growth in vivo. As the results showed, CD73 was highly expressed in the colorectal cancer cell lines. CD73 promoted colorectal cancer cell proliferation both in vivo and in vitro. CD73 activated EGFR and the β-catenin/cyclin D1 signaling pathways through its enzyme and non-enzyme activities. All of the results confirmed that CD73 promotes the growth of human colorectal cancer cells through EGFR and the β-catenin/cyclin D1 signaling pathway. CD73 may be used as a valuable biomarker of colorectal cancer.

MicroRNAs (miRNAs) are small non-coding RNAs that are involved in tumor initiation and development by suppressing target gene expression. miRNA-154 has been shown to be important in tumorigenesis in many types of cancers. However, its role in osteosarcoma (OS) remains unknown. In the present study, we focused on the roles and mechanisms of miR‑154 in OS development. The results of quantitative RT‑PCR showed that miR‑154 expression was decreased in primary OS tumor samples and cell lines compared to levels in the matched adjacent normal tissues and human normal osteoblast cells (NHOst). Restoration of expression in U2OS cells inhibited cell proliferation, colony formation, migration and invasion, as well as induced cell cycle arrest at the G1 stage. Bioinformatic prediction suggested that Wnt5a is a target gene of miR‑154. It was further verified that Wnt5a is a target gene of miR‑150 in OS cells using luciferase assay, mRNA and protein expression analysis. Wnt5a was upregulated in OS cell lines and primary tumor samples, and its mRNA expression level was negatively correlated with the miR‑154 level in the OS tissues. Restored expression of Wnt5a weakened miR‑154‑mediated suppression of tumor progression. Taken together, these findings suggest that miR‑154 functions as a tumor suppressor in OS by partially suppressing Wnt5a expression.

The involvement of miR-335 in csolorectal cancer (CRC) development remains controversial. Here, we found that miR-335 was highly up-regulated in CRC specimens relative to normal mucosa, and high miR-335 expression level was markedly associated with the tumour size and differentiation of CRC. The overexpression of miR-335 in CRC cells facilitated cell proliferation in vitro and tumour growth in vivo. RASA1 was validated as a target of miR-335 that was downregulation in CRC. Forced expression of miR-335 silenced RASA1 and triggered Ras/ERK cascade in CRC. Together, miR-335-RASA1 contributes to cell growth in CRC, and elucidation of downstream pathway will provide new insights into the molecular mechanisms of CRC progression.

Previous studies have shown that protein inhibitor of activated STAT (PIAs)xα is crucial in protein sumoylation and is associated with cancer cell progression. However, the mechanism underlying the inhibitory effect on cancer cells, which may assist in developing novel treatment strategies in cancer remains to be elucidated. In present study, the expression levels of PIAsxα from tissue samples of osteosarcoma and adjacent tissues from 25 patients were analyzed using reverse transcription-quantitative polymerase chain reaction, western blot and immunohistochemical analyses. In addition, techniques using an overexpression vector and small interfering (si)RNAs were used to examine the effect of PIAsxα on osteosarcoma cells. Finally, using xenograft U2-OS osteosarcoma cells overexpressing PIAsxα, the effect of PIAsxα on osteosarcoma formation was determined. The results revealed low expression of PIAsxα in osteosarcoma tissues. In addition, following overexpression of PIAsxα, the apoptotic rates were significantly increased. The rate of G2/M arrest was at the highest level in the overexpression group, compared with other groups assessed. Furthermore, the expression levels of cyclin D1 and cyclin D3 were inhibited following PIAsxα increase, indicating the repressive effects of PIAsxα on cell cycle. Accordingly, cyclin D kinase (CDK) genes, including CDK4, CDK6 and CDK8, increased markedly following treatment with PIAsxα siRNAs. The expression levels of CDK4, CDK6 and CDK8 decreased significantly in the overexpression group, compared to the other groups. Furthermore, high expression levels of PIAsxα inhibited tumor formation in a nude mouse model. Taken together, these findings provide evidence for the effects of PIAsxα and its mechanism on osteosarcoma progression, which offers novel insight into sumoylation and the cell cycle in osteosarcoma.

Gastric cancer (GC) is the third most common cause of cancer death worldwide. Natural killer cells play an important role in the immune defense against transformed cells. They express the activating receptor NKG2D, whose ligands belong to the MIC and ULBP/RAET family. Although it is well established that these ligands are generally expressed in tumors, the association between their expression in the tumor and gastric mucosa and clinical parameters and prognosis of GC remains to be addressed. In the present study, MICA and MICB expression was analyzed, by flow cytometry, in 23 and 20 pairs of gastric tumor and adjacent non-neoplasic gastric mucosa, respectively. Additionally, ligands expression in 13 tumors and 7 gastric mucosa samples from GC patients were evaluated by immunohistochemistry. The mRNA levels of MICA in 9 pairs of tumor and mucosa were determined by quantitative PCR. Data were associated with the clinicopathological characteristics and the patient outcome. MICA expression was observed in 57% of tumors (13/23) and 44% of mucosal samples (10/23), while MICB was detected in 50% of tumors (10/20) and 45% of mucosal tissues (9/20). At the protein level, ligand expression was significantly higher in the tumor than in the gastric mucosa. MICA mRNA levels were also increased in the tumor as compared to the mucosa. However, clinicopathological analysis indicated that, in patients with tumors >5 cm, the expression of MICA and MICB in the tumor did not differ from that of the mucosa, and tumors >5 cm showed significantly higher MICA and MICB expression than tumors ≤5 cm. Patients presenting tumors >5 cm that expressed MICA and MICB had substantially shorter survival than those with large tumors that did not express these ligands. Our results suggest that locally sustained expression of MICA and MICB in the tumor may contribute to the malignant progression of GC and that expression of these ligands predicts an unfavorable prognosis in GC patients presenting large tumors.

Virus-based nanoparticles have shown promise as vehicles for delivering therapeutic genes. However, the rational design of viral vectors that enable selective tropism towards particular types of cells and tissues remains challenging. Here, we explored structural-functional relationships of the adeno-associated virus 2 (AAV2) vector by expanding its genetic code during production. As a proof-of-principle, an azide moiety was strategically displayed on the vector capsid as a bioorthogonal chemical reporter. Upon bioorthogonal conjugation of AAV2 with fluorophores and cyclic arginyl-glycyl-aspartic acid ligands at certain modifiable sites, we characterized in vitro and in vivo AAV2 movement and enhanced tropism selectivity towards integrin-expressing tumor cells. Targeting AAV2 vectors resulted in selective killing of U87 glioblastoma cells and derived xenografts via the herpes simplex virus suicide gene thymidine kinase, with the potency of ganciclovir being increased by 25-fold. Our results demonstrated successful rational modification of AAV2 as a targeting delivery vehicle, establishing a facile platform for precision engineering of virus-based nanoparticles in basic research and therapeutic applications.