miR-125b reverses cisplatin resistance by regulating autophagy via targeting RORA/BNIP3L axis in lung adenocarcinoma.

The platinum-based chemotherapy is one of the most frequently used treatment protocols for lung adenocarcinoma (LUAD), and chemoresistance, however, usually results in treatment failure and limits its application in the clinic. It has been shown that microRNAs (miRNAs) play a significant role in tumor chemoresistance. In this study, miR-125b was identified as a specific cisplatin (DDP)-resistant gene in LUAD, as indicated by the bioinformatics analysis and the real-time quantitative PCR assay. The decreased serum level of miR-125b in LUAD patients was correlated with the poor treatment response rate and short survival time. MiR-125b decreased the A549/DDP proliferation, and the multiple drug resistance- and autophagy-related protein expression levels, which were all reversed by the inhibition of miR-125b. In addition, xenografts of human tumors in nude mice were suppressed by miR-125b, demonstrating that through autophagy regulation, miR-125b could reverse the DDP resistance in LUAD cells, both in vitro and in vivo. Further mechanistic studies indicated that miR-125b directly repressed the expression levels of RORA and its downstream BNIP3L, which in turn inhibited autophagy and reversed chemoresistance. Based on these findings, miR-125b in combination with DDP might be an effective treatment option to overcome DDP resistance in LUAD.

TGF-ß-regulated different iron metabolism processes in the development and cisplatin resistance of ovarian cancer.

The impact of different iron metabolism processes (DIMP) on ovarian cancer remains unclear. In this study, we employed various gene chips and databases to investigate the role of DIMP in the initiation and development of ovarian cancer. cBioPortal was used to determine mutations in DIMP-associated genes in ovarian cancer. Kaplan-Meier plotter was used to examine the influence of DIMP on the prognosis of ovarian cancer. By analyzing 1669 serous ovarian cancer cases, we identified a range of mutations in iron metabolism genes, notably in those coding for the transferrin receptor (19%), melanotransferrin (19%), and ceruloplasmin (10%) in the iron import process, and glucose-6-phosphate isomerase (9%), hepcidin antimicrobial peptide (9%), metal regulatory transcription factor 1 (8%), and bone morphogenetic protein 6 (8%) in the iron regulation process. Compared to the unaltered group, the group with gene alterations exhibited a higher tumor mutation burden count (43 vs. 54) and more advanced histologic grade (78.19% vs. 87.90%). Compared to the normal ovarian counterparts, a reduction in expression was observed in 9 out of the 14 genes involved in iron utilization and 4 out of the 5 genes involved in iron export in ovarian cancer; in contrast, an increase in expression was observed in 2 out of the 3 genes involved in iron storage in ovarian cancer. Furthermore, in cisplatin-resistant cells compared to cisplatin-sensitive ones, the expression of all genes in iron storage and 13 out of 14 genes in iron import was decreased, while that of 8 out of the 10 genes in iron utilization was increased. In addition, survival curve analysis indicated that a higher expression in the majority of genes in the iron import process (12/21), or a reduced expression in most genes in the iron export process (4/5) correlated with poor progression-free survival. Additionally, TGF-ß could regulate the expression of most iron metabolism-associated genes; particularly, expression of genes involved in the iron storage process (2/2) was inhibited after TGF-ß1 or TGF-ß2 treatment. In conclusion, DIMP plays multifaceted roles in the initiation, chemo-resistance, and prognosis of ovarian cancer. Therapeutically targeting DIMP may pave the way for more tailored treatment approaches for ovarian cancer.

Nitric oxide in multikinase inhibitor-induced hand-foot skin reaction.

Hand-foot skin reaction (HFSR) is the most debilitating and prevalent side effect caused by multikinase inhibitors (MKIs) that share vascular endothelial growth factor receptor (VEGFR) as the common inhibition target, such as sorafenib, regorafenib, axitinib, etc. Though not life-threatening, HFSR can significantly deteriorate patients' quality of life and jeopardize the continuity of cancer therapy. Despite years of efforts, there are no FDA-approved treatments for HFSR and the understanding of the precise pathogenic mechanism is still limited. In this study, we hypothesized that nitric oxide has the potential therapeutic effect to reverse the toxicity caused by MKI through upregulation of several VEGF/VEGFR downstream signaling pathways. We found that glyceryl trinitrate (GTN), a nitric oxide donor, could stimulate cell proliferation, migration, and protect cells from apoptosis induced by MKIs in vitro. Local application of GTN mitigated tissue damage in a rat model, while not impacting the anti-tumor effect of the MKI in HepG2 tumor-bearing mice. Finally, GTN ointment alleviated cutaneous damages and improved quality of life in 6 HFSR patients. Our study proposed and validated the mechanism to counteract VEGFR inhibition, providing GTN as the potential treatment to MKI-induced HFSR, which may further improve the therapeutic window of various MKI based cancer therapies.

hsa_circ_0062019 promotes the proliferation, migration, and invasion of prostate cancer cells via the miR-195-5p/HMGA2 axis.

Circular RNA (circRNA) is a new class of non-coding RNA. It was reported that circRNA involves in the metastasis of cancer. The aim of this study is to explore the role and mechanism of circRNA hsa_circ_0062019 in the development of prostate cancer (PCa). Our results showed that hsa_circ_0062019 was highly expressed in PCa cell lines. Cell Counting Kit-8 assay revealed that upregulation of hsa_circ_0062019 boosted PCa cell proliferation, and silencing of hsa_circ_0062019 inhibited cell proliferation. Meanwhile, transwell assay proved that upregulation of hsa_circ_0062019 facilitated PCa cell invasion and migration, while downregulation of hsa_circ_0062019 inhibited these malignant phenotypes. Furthermore, luciferase reporter assay proved the binding of hsa_circ_0062019 with miR-195-5p and the binding between miR-195-5p and high mobility group AT-hook 2 (HMGA2), suggesting that hsa_circ_0062019 promoted the expression of HMGA2 by sponging miR-195-5p. In addition, our results revealed that the hsa_circ_0062019-induced PCa cell malignant phenotypes were notably reversed by the downregulation of HMGA2. Overall, our study demonstrated that hsa_circ_0062019 promoted PCa cell proliferation, migration, and invasion via upregulation of HMGA2 expression by sponging miR-195-5p. Our study proved a novel molecular mechanism of PCa development and provided a potential target for the treatment of PCa.

Phase I Study of the Pan-PI3K Inhibitor Buparlisib in Adult Chinese Patients with Advanced Solid Tumors.

BACKGROUND/AIM: The phosphatidylinositol-3-kinase (PI3K) signaling pathway is frequently activated in cancer. Buparlisib (BKM120), an oral pan-PI3K inhibitor, inhibits proliferation of human cancer in preclinical models. Studies of buparlisib in Western and Japanese adults with advanced solid tumors established a recommended dose of 100 mg/day and showed an acceptable safety profile and evidence of efficacy. This phase I dose-escalation/expansion study aimed to establish the maximum tolerated dose (MTD) of single-agent, once daily oral buparlisib in Chinese patients with advanced solid tumors. MATERIALS AND METHODS: Patients (n=32; primary tumor site: lung (n=15), breast (n=10) or head and neck (n=7); ≥2 prior lines of antineoplastic therapy (n=26)) received 80 mg (n=15) or 100 mg (n=17) daily buparlisib. RESULTS: Five patients experienced dose-limiting toxicities: grade (G)3 depression (n=1), G2 hyperglycemia (n=3) and G3 hyperglycemia (n=1). Most frequent buparlisib-related adverse events were hyperglycemia (n=18; 56%), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increase (n=9; 28%), as well as anxiety (n=6; 19%); most common buparlisib-related G3/4 adverse events: hyperglycemia (n=3; 9%), ALT and AST increase (n=2; 6%), as well as gamma-glutamyltransferase increase (n=2; 6%). Best response was stable disease (SD) in 10 patients (31%). CONCLUSION: The MTD of buparlisib was declared as 100 mg/day. Safety, efficacy and pharmacokinetic data from this study were similar to those previously reported in Western and Japanese populations.

Development of multiple malignancies following long-term glucocorticoid therapy in a patient with leukocytoclastic vasculitis: A case report.

Leukocytoclastic vasculitis (LCV) is a neutrophilic inflammation of the blood vessels. LCV may present as a paraneoplastic syndrome occurring before, synchronously with, or after the diagnosis of malignancy. In this study, we report a unique case of multiple malignancies developing simultaneously in a patient with a long history of LCV. The patient was originally diagnosed with LCV and received long-term glucocorticoid treatment. After 11 years of therapy, the patient developed three primary malignancies, including small-cell lung carcinoma, gastric adenocarcinoma and colonic adenocarcinoma. It is likely that LCV was not a paraneoplastic syndrome in this case, but rather an independent process, and the development of multiple cancers is likely associated with the long-term glucocorticoid treatment, which caused imbalance of the immune system. Although the development of cancer during the course of glucocorticoid treatment is very rare, clinicians must be aware of this possible association and immunodysregulation may play a role in this context.

Syringotropic mycosis fungoides responding well to VELP chemotherapy: A case report.

Mycosis fungoides (MF), a low-malignant lymphoproliferative disorder, is the most common type of cutaneous T-cell lymphoma. The current study reported a case of syringotropic MF, a rare variant of MF, which presented with reactive B cell proliferation, lymphoid follicle formation, hair loss and lymphadenopathy. The clinical manifestations of the patient were MF-like lumps. Immunohistochemical staining of AE1/AE3 showed that there were abundant infiltrated lymphocytes surrounding the syringocystadenoma. In addition, the direction of the lymphocyte arrangement was consistent with the meandering direction of syringocystadenoma. The patient did not respond to 1-month narrowband (311-nm) ultraviolet therapy; however, a good response was obtained subsequent to one cycle of chemotherapy with vincristine sulfate, etoposide, L-asparaginase and prednisone acetate (know as the VELP regimen). After 7 days of VELP chemotherapy, the skin lesions were ameliorated, hair loss was improved and lymphadenopathy disappeared. No lymphadenopathy or new skin lesions were observed during 6 months of follow-up.

Prognostic significance of Dicer expression in hepatocellular carcinoma.

Dicer is a RNaseIII endonuclease of the microRNA processing pathway, which is implicated in carcinogenesis of various types of human cancer. The present study assessed the expression level of Dicer in hepatocellular carcinoma (HCC) tissue to evaluate its association with HCC tumorigenesis. A low expression of Dicer was significantly associated with a shorter postoperative survival time of patients with HCC, which was assessed using the log-rank test with Kaplan-Meier survival analysis. Multivariate analysis identified that Dicer expression was an independent predictor for HCC outcome (relative risk, 0.660; 95% confidence interval, 0.506-0.861; P=0.002). A functional assay demonstrated that Dicer overexpression inhibited the proliferation and promoted the apoptosis of HCC cells. In addition, a Transwell assay revealed that Dicer markedly inhibited the migration and invasion of HCC cells. The present findings indicate that Dicer expression modified the outcomes of HCC patients by inhibiting proliferation, promoting apoptosis and inhibiting metastasis of HCC cells.

Knockdown of cathepsin L sensitizes ovarian cancer cells to chemotherapy.

Ovarian cancer is a leading gynecological malignancy associated with high mortality. The development of acquired drug resistance is the primary cause of chemotherapy failure in the treatment of ovarian cancer. To examine the mechanism underlying paclitaxel resistance in ovarian cancer and attempt to reverse it, the present study induced a TAX-resistant ovarian cancer cell line, SKOV3/TAX. Cathepsin L (CTSL) has been found to be overexpressed in ovarian cancer. The aim of the present study was to investigate the possible involvement of CTSL in the development of TAX resistance in ovarian cancer. CTSL expression was knocked down in SKOV3 ovarian cancer cells and their phenotypic changes were analyzed. The effects of silenced CTSL on the resistant cell line were investigated by proliferation and apoptosis analysis compared with control SKOV3 cells. CTSL was more highly expressed in SKOV3/TAX cells compared with SKOV3 cells. Paclitaxel treatment downregulated the expression of CTSL in SKOV-3 but not in the paclitaxel-resistant SKOV3/TAX cells. CTSL small hairpin RNA (shRNA) knockdown significantly potentiated apoptosis induced by paclitaxel compared with SKOV3/TAX cells transfected with control shRNA, suggesting that CTSL contributes to paclitaxel resistance in ovarian cancer cells and that CTSL silencing can enhance paclitaxel-mediated cell apoptosis. Thus, CTSL should be explored as a candidate of therapeutic target for modulating paclitaxel sensitivity in ovarian cancer.

Association between the histological subtype of lung adenocarcinoma, EGFR/KRAS mutation status and the ALK rearrangement according to the novel IASLC/ATS/ERS classification.

The present study aimed to investigate the association between epidermal growth factor receptor (EGFR)/Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations, anaplastic lymphoma receptor tyrosine kinase (ALK) rearrangements and the morphological characteristics of lung adenocarcinoma (LAC), according to the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) classification in a large group of patients with primary LAC. A total of 200 patients with invasive LAC who had undergone complete resections at the Beijing Chest Hospital (Beijing, China) were randomly selected. The morphology of the samples was reassessed in 5% increments by two pathologists, according to the IASLC/ATS/ERS scheme. EGFR and KRAS mutations were tested by direct DNA sequencing. ALK rearrangements were screened by immunohistochemistry on a Benchmark XT stainer. The data revealed that EGFR and KRAS mutations, and ALK rearrangements were identified in 46.0% (92/200), 9.0% (18/200) and 11.5% (23/200) of the patients, respectively. The EGFR/KRAS mutations and ALK rearrangements were mostly exclusive. However, 1 patient exhibited the coexistence of the EGFR (at exon 20) and KRAS (codon 12) mutations, and another patient exhibited the coexistence of the EGFR mutation (at exon 21) and the ALK gene fusion. EGFR mutations were indicated to be closely associated with the acinar predominant (43/77; 55.8%; P=0.030) and papillary predominant (26/49; 53.1%; P=0.006) subtypes. KRAS mutations were more commonly associated with the solid predominant subtype (9/52; 17.3%; P=0.023) and invasive mucinous LAC (5/10; 50.0%; P=0.004), and less commonly associated with the acinar predominant subtype (1/77; 1.3%; P=0.002). ALK rearrangements more commonly occurred in the solid predominant subtype compared with other subtypes (13/52; 25%; P=0.002), and less commonly occurred in the papillary predominant subtype (1/49; 2.0%; P=0.004). Tumors harboring ALK rearrangements were characterized by signet-ring cell (7/9; 77.8%; P<0.0001) and cribriform (7/12; 58.3%; P<0.0001) patterns. The association between the mutation status and histological subtype in LAC was distinct. The predominant subtype according to the IASLC/ATS/ERS classification provided important information for gene mutations and integrated clinical findings to improve the treatment of LAC patients.

A sensitive and practical method to detect the T790M mutation in the epidermal growth factor receptor.

The current study aimed to develop a method to rapidly, sensitively and practically screen for the epidermal growth factor receptor (EGFR) T790M mutation. This method combines an allele-specific competitive blocker (ACB) with a TaqMan quantitative polymerase chain reaction (PCR) amplification refractory mutation system (ARMS) in a one-step reaction. Using a mimic of a human genomic DNA panel containing serially diluted mutant alleles, the performance efficacy of this method was assessed. Using this method, the EGFR T790M mutation was detected in tyrosine kinase inhibitor (TKI)-naïve samples obtained from 27 non-small cell lung cancer (NSCLC) patients with EGFR-activating mutations. The association between de novo T790M mutations and the clinical benefit of EGFR-TKI treatment was also analysed. The sensitivity of this method was as low as 0.01%. In the samples from the 27 NSCLC patients, this method identified 6 mutant patients (22.2%), which was higher than the detection rate with scorpion ARMS (0.0%). No clinical variables were associated with the occurrence of a de novo T790M mutation. The median progression-free survival time in the TKI-naïve patients with a T790M mutation was shorter that that of patients without the mutation, but the difference was not significant (3.2 vs. 19.5 months, respectively; P=0.256). The median overall survival time in the groups with or without T790M mutation also did not significantly differ (10 vs. 20 months, respectively; P=0.689). Overall, the ACB-ARMS PCR method could be useful for detecting the EGFR T790M mutation in clinical samples that contain only a small number of mutant alleles. The clinical significance of a de novo T790M mutation should be further investigated.

Effect of cytokine-induced killer cells on immune function in patients with lung cancer.

Cytokine-induced killer (CIK) cells have been used as adoptive immunotherapy in cancer. The present study evaluated the effect of CIK cells on immune function in patients with lung cancer. Patients were divided into three groups, according to the treatment received prior to CIK cell treatment: CIK group (no prior treatment), Che-Sur group (prior chemotherapy and surgery) and Che-Rad group (prior chemotherapy and radiotherapy). Following treatment, the average percentage of cluster of differentiation (CD)3+CD4+, CD3+, natural killer (NK) and NKT cells in peripheral blood was significantly higher than that prior to CIK treatment in the Che-Sur and CIK groups, and the levels of interferon-γ in serum were significantly higher than those prior to CIK treatment in the Che-Sur and CIK groups. On the contrary, the levels of interleukin-10 had decreased in these groups following CIK treatment. Subsequently, patients were divided into three groups according to the percentage of CD3+CD56+ CIK cells that were administered to the patients. The number of NK and NKT cells increased with increasing number of CD3+CD56+ cells. The patients in the CIK and Che-Sur groups were the most benefited ones following CIK treatment, contrarily to those in the Che-Rad group, since the increase in the number of CD3+CD56+ CIK cells in the aforementioned patients enhanced the number of NK cells, which exhibit antitumor activity.

Expression levels of cytokines and chemokines increase in human peripheral blood mononuclear cells stimulated by activation of the Toll-like receptor 5 pathway.

Recognition of pathogen-associated molecular patterns by Toll-like receptors (TLRs) activates innate and adaptive immune responses. Among the 11 members of the human TLR family, TLR-5 is known to play an important role in the defense against bacterial invasion by binding to flagellin, a conserved component of bacteria. Previous studies have demonstrated that the activation of TLR-5 induces the expression of interleukin (IL)-10, IL-12 and interferon-ß. However, the aim of the present study was to analyze the expression of a wider range of immune-related molecules upon stimulation with a TLR-5 agonist. Following isolation from healthy volunteers, peripheral blood mononuclear cells (PBMCs) were stimulated with flagellin, a TLR-5 agonist. At 4 h after stimulation, quantitative polymerase chain reaction (PCR) and an antibody chip array were conducted to determine the mRNA expression levels of immune molecules and the protein secretion of immune molecules in the supernatant, respectively. The PCR results revealed that activation of TLR-5 significantly influenced the expression of a number of important molecules. In addition, the antibody chip array demonstrated the induction (IL-8) and inhibition [monocyte chemoattractant protein (MCP)-1, MCP-3 and macrophage inflammatory protein-1α) of protein secretion following TLR-5 stimulation. Therefore, the present study demonstrated the importance of TLR-5 in regulating the biological function of PBMCs. In the future, research should focus on the roles of the candidate molecules in TLR-5-mediating functions.

Superior mesenteric artery syndrome caused by surgery and radiation therapy for a brain tumor: A case report.

Superior mesenteric artery syndrome (SMAS) is defined as an obstruction of the third part of duodenum due to compression by the superior mesenteric artery. Although traumatic brain injury is a risk factor for SMAS, few cases of SMAS resulting from brain surgery have been reported. SMAS has been observed to occur following neurosurgical surgery in pediatric patients but, to the best of our knowledge, no such cases have been reported in adults. The present study reports the case of a 21-year-old female patient who developed SMAS after persistent vomiting and prolonged weight loss following cerebellar tumor resection and cranial irradiation. The SMAS was confirmed by computed tomography and resolved following successful nutritional management.

Cigarette smoke induces the expression of Notch3, not Notch1, protein in lung adenocarcinoma.

The aim of the present study was to determine the effect of cigarette smoke on the expression of Notch proteins in lung adenocarcinoma (LAC). Protein expression levels of Notch1 and Notch3 were analyzed using immunohistochemistry in 102 human LAC specimens. Of these, 52 were obtained from smokers and 50 from non-smokers. In addition, cigarette smoke extract (CSE) at varying concentrations (1, 2.5 and 5%) was administered to A549 cells. The expression of Notch1 and Notch3 protein was then detected by western blot analysis at different time points (0, 8, 24 and 48 h). Of the 102 LAC specimens, 42 (41.2%) were positive for Notch1 and 63 (61.8%) were positive for Notch3. There was no significant difference in the level of Notch1 expression between smokers and non-smokers with LAC (P>0.05). The positive rate and staining intensity of Notch3 expression were increased in the smokers compared with the non-smokers (P<0.05). The expression of Notch3 protein in A549 cells increased in a time- and dose-dependent manner following treatment with CSE, whilst the expression of Notch1 protein appeared stable. The results suggested that cigarette smoke was able to induce the expression of Notch3, not Notch1, protein in LAC. The data revealed an upregulation of Notch3 in LAC following cigarette smoke exposure. Such findings may provide a novel therapeutic target for the treatment of LAC.

Imatinib-based therapy in adult Philadelphia chromosome-positive acute lymphoblastic leukemia: A case report and literature review.

Acute lymphoblastic leukemia (ALL) has a rapid onset and rarely occurs with exclusive prodrome of general osteoporosis and vertebral compression fractures. However, Philadelphia chromosome-positive (Ph+) ALL has a poor prognosis, even when patients are treated with intensive chemotherapy, and the first-line effective treatment requires further elucidation. The present study focused on a 56-year-old Chinese male patient who initially presented with spontaneous bone fractures and was ultimately diagnosed as Ph+ ALL after 6 months, which required to preliminarily exclude a working diagnosis of myeloma. Apart from intensive chemotherapy, the patient successfully completed an imatinib-based regimen and achieved complete remission (CR) 2 weeks later. Subsequently, the patient was subjected to consolidation treatment using the same imatinib regimen combined with interferon-α 2b for 9 courses. In November 2013, the patient had achieved persistent hematological and molecular genetic normality for ~16 months after the initial CR. In conclusion, Ph+ ALL must be considered in the differential diagnosis of adults experiencing unexplained bone disease.

Thoracoscopy-assisted first rib resection for the treatment of thoracic outlet syndrome caused by fibrous dysplasia: A report of two cases.

This study reports two rare cases of thoracic outlet syndrome (TOS) caused by fibrous dysplasia of the first rib. Two patients, aged 19 and 29 years old, were admitted with TOS in the lower trunk of the brachial plexus caused by an inflated first rib. In these two cases symptoms included hypoesthesia of the anterior medial aspect of the forearm and two fingers in the ulnar side, and progressive weakness of the upper limbs. Surgery was required to resect the first rib. Transaxillary and supraclavicular excisions were challenging to perform due to the involvement of the subclavian vasculature and brachial plexus. Thoracoscopy was used in these cases in order to peel the pleura off the first rib and facilitate resection by the supraclavicular approach. None of the patients exhibited nerve or vascular complications following the surgery.

High plasma levels of oxidatively modified low-density lipoproteins are associated with the suppressed expression of immunomodulatory molecules in patients with hematological malignancies.

Dyslipidemia is a common feature in immunosuppressed patients, such as kidney and bone marrow transplantation recipients and patients with breast, prostate or gynecological carcinoma or acute lymphoblastic leukemia. In addition, high levels of oxidatively modified low-density lipoproteins (oxLDLs) are closely associated with carcinogenesis. There are, however, no reports on the association between the serum oxLDL levels and the expression of important immunomodulatory molecules in patients with hematological disorders. In the present study, 39 patients with hematological disorders were stratified into four groups: Two groups with malignancies [chronic myeloid leukemia (CML) and acute myeloblastic leukemia (AML)] and two groups without malignancies [myelodysplastic syndrome (MDS) and iron deficiency anemia (IDA)]. Immunomodulatory molecules were monitored in these groups. The enzyme-linked immunosorbent assay results indicated that the plasma oxLDL levels were significantly higher in patients with AML or CML than those in patients with MDS or IDA. The quantitative polymerase chain reaction results revealed that the expression of numerous important immunomodulatory elements, including tumor-related genes, immunological and inflammatory cytokines, defense-responsive genes, genes regulating cell proliferation, adhesion and migration molecules and leukocyte chemotaxis genes, showed considerable variation in patients with hematological disorders, particularly in those with MDS or IDA, as compared with the expression in the healthy volunteers. The present study demonstrated that, in patients with a hematological malignancy (either AML or CML), the activation of numerous immune response-related molecules was inhibited. Thus, an association between hematological malignancies and dyslipidemia, i.e. high levels of oxLDL, is suggested. Further research is necessary to investigate how oxLDL influences cancer progression.

miR-34a inhibits cell proliferation in prostate cancer by downregulation of SIRT1 expression.

MicroRNA-34a (miR-34a) functions as a tumor suppressor gene and inhibits abnormal cell growth by regulating the expression of other genes. The role of miR-34a in regulating sirtuin 1 (SIRT1) in prostate cancer remains unclear. The objective of the present study was to investigate the biological function and molecular mechanisms of miR-34a regulation of SIRT1 in human prostate cancer samples and the human prostate cancer cell line, PC-3. Fresh prostate tissues were obtained from patients, and the miR-34a expression in prostate cancer tissues was measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). qPCR and western blotting were performed to assess the effects of miR-34a overexpression on SIRT1 regulation in PC-3 cells, and the cell growth was assessed by Cell Counting Kit-8 (CCK-8). Flow cytometry was used to assess the cell cycle status of the cells. The miR-34a expression levels in prostate cancer tissues were significantly reduced compared with adjacent normal prostate tissues (P<0.05). SIRT1 expression levels in PC-3 cells with over-expression of miR-34a were significantly reduced compared with those in the negative control (P<0.05). The over-expression of miR-34a inhibited PC-3 cells growth and resulted in increased cell cycle arrest compared with the negative control (P<0.05). In conclusion, miR-34a inhibits the human prostate cancer cell proliferation, in part, through the downregulation of SIRT1 expression.