MicroRNA-135b Regulates Leucine Zipper Tumor Suppressor 1 in Cutaneous Squamous Cell Carcinoma

Micro RNA Dysregulation in Keratinocyte Carcinomas: Clinical Evidence, Functional Impact, and Future Directions

The keratinocyte carcinomas, basal cell carcinoma (BCC), and cutaneous squamous cell carcinoma (cSCC), are the most common cancers in humans. Recently, an increasing body of literature has investigated the role of miRNAs in keratinocyte carcinoma pathogenesis, progression and their use as therapeutic agents and targets, or biomarkers. However, there is very little consistency in the literature regarding the identity of and/or role of individual miRNAs in cSCC (and to a lesser extent BCC) biology. miRNA analyses that combine clinical evidence with experimental elucidation of targets and functional impact provide far more compelling evidence than studies purely based on clinical findings or bioinformatic analyses. In this study, we review the clinical evidence associated with miRNA dysregulation in KCs, assessing the quality of validation evidence provided, identify gaps, and provide recommendations for future studies based on relevant studies that investigated miRNA levels in human cSCC and BCC. Furthermore, we demonstrate how miRNAs contribute to the regulation of a diverse network of cellular functions, and that large-scale changes in tumor cell biology can be attributed to miRNA dysregulation. We highlight the need for further studies investigating the role of miRNAs as communicators between different cell types in the tumor microenvironment. Finally, we explore the clinical benefits of miRNAs as biomarkers of keratinocyte carcinoma prognosis and treatment.

A review on the importance of miRNA-135 in human diseases

MicroRNA-135 (miR-135) is a microRNA which is involved in the pathoetiology of several neoplastic and non-neoplastic conditions. Both tumor suppressor and oncogenic roles have been reported for this miRNA. Studies in prostate, renal, gallbladder and nasopharyngeal cancers as well as glioma have shown down-regulation of miR-135 in cancerous tissues compared with controls. These studies have also shown the impact of miR-135 down-regulation on enhancement of cell proliferation and aggressive behavior. Meanwhile, miR-135 has been shown to be up-regulated in bladder, oral, colorectal and liver cancers. Studies in breast, gastric, lung and pancreatic cancers as well as head and neck squamous cell carcinoma have reported dual roles for miR-135. Dysregulation of miR-135 has also been noted in various non-neoplastic conditions such as Alzheimer’s disease, atherosclerosis, depression, diabetes, Parkinson, pulmonary arterial hypertension, nephrotic syndrome, endometriosis, epilepsy and allergic conditions. In the current review, we summarize the role of miR-135 in the carcinogenesis as well as development of other disorders.

Non-coding RNAs in skin cancers:Biological roles and molecular mechanisms

Cutaneous malignancies, including basal cell carcinoma, cutaneous squamous cell carcinoma, and cutaneous melanoma, are common human tumors. The incidence of cutaneous malignancies is increasing worldwide, and the leading cause of death is malignant invasion and metastasis. The molecular biology of oncogenes has drawn researchers’ attention because of the potential for targeted therapies. Noncoding RNAs, including microRNAs, long noncoding RNAs, and circular RNAs, have been studied extensively in recent years. This review summarizes the aspects of noncoding RNAs related to the metastasis mechanism of skin malignancies. Continuous research may facilitate the identification of new therapeutic targets and help elucidate the mechanism of tumor metastasis, thus providing new opportunities to improve the survival rate of patients with skin malignancies.

Molecular Mechanisms of Cutaneous Squamous Cell Carcinoma

Non-melanoma skin cancers are cutaneous malignancies representing the most common form of cancer in the United States. They are comprised predominantly of basal cell carcinomas and squamous cell carcinomas (cSCC). The incidence of cSCC is increasing, resulting in substantial morbidity and ever higher treatment costs; currently in excess of one billion dollars, per annum. Here, we review research defining the molecular basis and development of cSCC that aims to provide new insights into pathogenesis and drive the development of novel, cost and morbidity saving therapies.

Cutaneous squamous cell carcinoma arising in immunosuppressed patients: a systematic review of tumor profiling studies

As solid organ transplantation becomes more prevalent, more individuals are living as members of the immunosuppressed population with an elevated risk for cutaneous squamous cell carcinoma (cSCC). Although great progress has been made in understanding the pathogenesis of cSCC in general, little is known about the drivers of tumorigenesis in immunosuppressed patients and organ-transplant recipients, specifically. This systematic review sought to synthesize information regarding the genetic and epigenetic alterations as well as changes in protein and mRNA expression that place this growing population at risk for cSCC, influence treatment response, and promote tumor aggressiveness. This review will provide investigators with a framework to identify future areas of investigation and clinicians with additional insight into how to best manage these patients.

Is miRNA Regulation the Key to Controlling Non-Melanoma Skin Cancer Evolution?

Non melanoma skin cancer (NMSC) is one of the most common types of skin cancer. It has a number of subtypes, which include basal cell carcinoma, cutaneous squamous cell carcinoma and Merkel cell carcinoma. MicroRNAs are short, non-coding RNA (ribonucleic acid) molecules, capable of regulating gene expression at a post transcriptional level. They play a pivotal role in a variety of physiologic cellular functions and pathologies, including malignant diseases. The development of miRNAs represents an important study field, which has been extensively exploited in melanoma for almost a decade with promising results, therefore we consider it a stepstone for further research projects also in non-melanoma skin cancers. The aim of our study was to explore the current literature in order to present the role of the different miRNAs in some of the most frequent types of NMSC pertaining to oncogenesis, evolution and therapy. The most relevant and accurate available data from the literature were evaluated. Our study concluded that there are almost 100 miRNAs which can be upregulated or downregulated and can play a role in oncogenesis. They can be easily identified in circulation, are stable and they can be important diagnosis/prognosis and therapy monitoring markers.

Identification of potential immune-related circRNA-miRNA-mRNA regulatory network in cutaneous squamous cell carcinoma

Circulating RNAs (circRNAs) are involved in tumor development and progression by participating in immune regulation. Nevertheless, the circRNAs expression profiles and their roles on the immunomodulatory effects in cutaneous squamous cell carcinoma (cSCC) have rarely been studied. In our study, we identified the differentially expressed circRNAs (DEcircRNAs), miRNAs (DEmiRNAs), mRNAs (DEmRNAs) in cSCC and established the circRNA competing endogenous RNAs (ceRNAs) network. Subsequently, the hub differentially expressed immune-related genes were identified and validated by immunochemistry as well as the GO and KEGG pathway analysis were performed. 54 differentially expressed circRNAs were identified and hub differentially expressed immune-related genes were identified and they were mostly associated with immune response in the progression of cSCC. Our results indicated that the potential immune-related circRNA-miRNA-mRNA network may assist in understanding the molecular mechanisms underlying the carcinogenesis and progression in cSCC. Moreover, the immune-related genes may provide an insight into the pathogenesis, molecular biomarkers, and potential therapeutic targets for cSCC patients.

The Role of Non-Coding RNAs as Prognostic Factor, Predictor of Drug Response or Resistance and Pharmacological Targets, in the Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the most common keratinocyte-derived skin cancer in the Caucasian population. Exposure to UV radiations (UVRs) represents the main risk carcinogenesis, causing a considerable accumulation of DNA damage in epidermal keratinocytes with an uncontrolled hyperproliferation and tumor development. The limited and rarely durable response of CSCC to the current therapeutic options has led researchers to look for new therapeutic strategies. Recently, the multi-omics approaches have contributed to the identification and prediction of the key role of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), circularRNAs (circRNAs) and long non-coding RNAs (lncRNAs) in the regulation of several cellular processes in different tumor types, including CSCC. ncRNAs can modulate transcriptional and post-transcriptional events by interacting either with each other or with DNA and proteins, such as transcription factors and RNA-binding proteins. In this review, the implication of ncRNAs in tumorigenesis and their potential role as diagnostic biomarkers and therapeutic targets in human CSCC are reported.

Identification of novel biomarkers and small-molecule compounds for nasopharyngeal carcinoma with metastasis

The purpose of this study was to investigate novel biomarkers and potential mechanisms in nasopharyngeal carcinoma (NPC) patients with metastasis.Two microarray datasets (GSE103611 and GSE36682) were obtained from GEO database, differentially expressed genes (DEGs) and differentially expressed miRNA (DEMs) were identified, Gene ontology (GO) as well as Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted with DEGs and DEMs targeted genes. Protein-protein interactions (PPI) network of the DEGs and DEMs targeted genes were constructed, furthermore, Connectivity Map (CMap) database was applied to select the potential drugs with therapeutic effects.Overall, we identified 396 upregulated and 19 downregulated DEGs. Additionally, we identified 1 upregulated DEM, miR-135b, and a downregulated DEM, miR-574-5p. Functional enrichment analysis indicated that both DEGs and DEMs targeted genes participated in biological process (BP) of regulation of transcription from RNA polymerase II promoter, DNA-templated positive regulation of transcription, and Epstein-Barr virus infection signaling pathway. Besides, upregulated EP300 gene was a hub node both in DEGs and DEMs target genes. CMap database analysis indicated that sanguinarine, verteporfin, and chrysin are potential drugs for prevention and treatment of NPC metastasis.In summary, the common hub gene, biological process and pathway identified in the study provided a novel insight into the potential mechanism of NPC metastasis. Furthermore, we identified several possible small molecule compounds for treatment of NPC metastasis.

Deciphering the Molecular Landscape of Cutaneous Squamous Cell Carcinoma for Better Diagnosis and Treatment

Cutaneous squamous cell carcinoma (cSCC) is a common type of neoplasia, representing a terrible burden on patients' life and clinical management. Although it seldom metastasizes, and most cases can be effectively treated with surgical intervention, once metastatic cSCC displays considerable aggressiveness leading to the death of affected individuals. No consensus has been reached as to which features better characterize the aggressive behavior of cSCC, an achievement hindered by the high mutational burden caused by chronic ultraviolet light exposure. Even though some subtypes have been recognized as high risk variants, depending on certain tumor features, cSCC that are normally thought of as low risk could pose an increased danger to the patients. In light of this, specific genetic and epigenetic markers for cutaneous SCC, which could serve as reliable diagnostic markers and possible targets for novel treatment development, have been searched for. This review aims to give an overview of the mutational landscape of cSCC, pointing out established biomarkers, as well as novel candidates, and future possible molecular therapies for cSCC.

MicroRNA Dysregulation in Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most frequent cancer in humans and it can be locally invasive and metastatic to distant sites. MicroRNAs (miRNAs or miRs) are endogenous, small, non-coding RNAs of 19–25 nucleotides in length, that are involved in regulating gene expression at a post-transcriptional level. MicroRNAs have been implicated in diverse biological functions and diseases. In cancer, miRNAs can proceed either as oncogenic miRNAs (onco-miRs) or as tumor suppressor miRNAs (oncosuppressor-miRs), depending on the pathway in which they are involved. Dysregulation of miRNA expression has been shown in most of the tumors evaluated. MiRNA dysregulation is known to be involved in the development of cutaneous squamous cell carcinoma (CSCC). In this review, we focus on the recent evidence about the role of miRNAs in the development of CSCC and in the prognosis of this form of skin cancer.

miR-1207-5p regulates the sensitivity of triple-negative breast cancer cells to Taxol treatment via the suppression of LZTS1 expression

Taxol-based chemotherapy is a conventional therapeutic approach for the treatment of triple-negative breast cancer (TNBC). However, the insensitivity of TNBC cells to Taxol greatly limits the anticancer effect of the drug and leads to patient mortality. The present study first evaluated the expression levels of microRNA (miR)-1207-5p in human normal breast epithelial MCF-10A cells and TNBC cell lines (MDA-MB-231, MDA-MB-436 and MDA-MB-453). The results revealed that the highest miR-1207-5p level was in MDA-MB-231, which suggested an oncogenic role of miR-1207-5p in TNBC. Therefore, MDA-MB-231 served as the present study's research model in subsequent experiments. The mRNAs that functioned as tumor suppressor factors for miR-1207-5p were then determined. Leucine zipper tumor suppressor gene 1 (LZTS1), which was predicted by TargetScan 6.2 and was supported by the results of a dual luciferase assay, was identified as a target of miR-1207-5p. AntagomiR-1207-5p increased LZTS1 mRNA and protein expressions, enhanced cell growth arrest and cell apoptosis induced by Taxol in MDA-MB-231 cells. Additionally, it was observed that, when compared with Taxol treatment, the combination of Taxol and antagomiR-1207-5p induced a sharp decrease in B-cell lymphoma 2 (Bcl-2) and phosphorylated-protein kinase B expression accompanied by an increase in the Bcl-2-associated X protein expression. Finally, miR-1207-5p expression was significantly increased, while LZTS1 expression was significantly decreased, in TNBC tissues when compared with normal adjacent tissues, and there was a negative correlation between miR-1207-5p and LZTS1 expression. In addition, there was a notable elevation in the expression of miR-1207-5p and a reduction in the expression of LZTS1 in the Taxol non-responsive TNBC tissues when compared with the Taxol-responsive TNBC tissues. The results of the present study suggested that miR-1207-5p may be a promising predictor of sensitivity towards Taxol in TNBC.

The microRNA landscape of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is a keratinocyte-derived skin tumor. It is the second-most-common cancer affecting the Caucasian population and is responsible for >20% of all skin-cancer-related deaths. The estimated incidence of non-melanoma skin cancer in the USA is >1000000 cases per year, of which roughly 20-30% are squamous cell carcinoma. To better understand and treat this challenging cancer, current research focuses on development of novel strategies to improve the understanding of tumor biogenesis on an individual basis. microRNAs are becoming important biomarkers in the diagnosis, prognosis and treatment of cSCC. This review describes the current knowledge on miRNA expression in cSCC and its role as a biomarker for personalized medicine.

Towards topical microRNA-directed therapy for epidermal disorders

There remains an unmet dermatological need for innovative topical agents that achieve better longterm outcomes with fewer side effects. Modulation of the expression and activity of microRNA (miRNAs) represents an emerging translational framework for the development of such innovative therapies because changes in the expression of one miRNA can have wide-ranging effects on diverse cellular processes associated with disease. In this short review, the roles of miRNA in epidermal development, psoriasis, cutaneous squamous cell carcinoma and re-epithelisation are highlighted. Consideration is given to the delivery of oligonucleotides that mimic or inhibit miRNA function using vehicles such as cell penetrating peptides, spherical nucleic acids, deformable liposomes and liquid crystalline nanodispersions. Formulation of miRNA-directed oligonucleotides with such skin-penetrating epidermal agents will drive the development of RNA-based cutaneous therapeutics for deployment as primary or adjuvant therapies for epidermal disorders.

The pathogenesis of cutaneous squamous cell carcinoma in organ transplant recipients

The pathogenesis of keratinocyte carcinoma following organ transplantation is multifactorial, and recent evidence suggests a complex and often synergistic interplay between the carcinogenic effects of ultraviolet radiation, compromised immune surveillance, direct pro- and anticarcinogenic effects of drugs, oncogenic viruses (in particular, beta-genus human papillomaviruses) and host genetic susceptibility factors. We present an overview of those factors for which there is currently the most convincing evidence and highlight important gaps in our knowledge. In particular, a clear understanding of the interdependence and relative contributions of these co-factors is currently lacking, yet has important implications for rational development of clinically relevant biomarkers and targeted strategies for treatment and prevention of post-transplant keratinocyte cancers.

MicroRNA-142-5p induces cancer stem cell-like properties of cutaneous squamous cell carcinoma via inhibiting PTEN

Cutaneous squamous cell carcinoma (cSCC) is a malignancy of keratinocyte-derived skin tumor, which is regarded as the second most common skin cancer worldwide. Accumulating evidence has established that microRNAs (miRNAs) can play a critical role in tumor initiation, progression, and metastasis including cSCC. Abnormal expression of hsa-miR-142-5p has been elaborated in various tumors. Nevertheless, its expression and function in the development of cSCC remain unclear. In our study, we found that the expression of hsa-miR-142-5p in cSCC cells were greatly overexpressed compared to human benign epidermal keratinocyte cells. Moreover, inhibited hsa-miR-142-5p can repress cSCC cell growth and induce apoptosis while upregulated hsa-miR-142-5p exhibited a reverse phenomenon. Recently, cancer stem cells (CSCs) which possess the ability of self-renewal and proliferation and are able to produce cancer cells have been widely reported. However, the correlation between hsa-miR-142-5p and CSCs in cSCC is still unknown. Interestingly, we observed that overexpressing hsa-miR-142-5p can induce CSC-like properties in cSCC via activating Wnt signaling. In addition, the luciferase reporter assay data and bioinformatics analysis demonstrated that hsa-miR-142-5p can target the 3'UTR of PTEN mRNA. Taken these together, we draw a conclusion that hsa-miR-142-5p can trigger cancer stem cell-like properties of cSCC through inhibition of PTEN. Our findings may provide hsa-miR-142-5p as a new therapeutic target for cSCC.

MiR-217 promotes cutaneous squamous cell carcinoma progression by targeting PTRF

Increasing evidences have suggested that microRNAs (miRNAs) act a critical role in tumor initiation, progression and metastasis. Deregulated expression of miR-217 has been identified in various tumors. However, the expression and role of miR-217 in the development of cutaneous squamous cell carcinoma (cSCC) remain unclear. In our study, we showed that miR-217 expression was upregulated in the cSCC tissues compared to adjacent non-tumor samples. We also demonstrated that miR-217 expression was upregualted in the cSCCcSCC cell lines. Overexpression of miR-217 promoted cSCCcSCC cell growth, cell cycle and invasion. We identified Polymerase I and Transcript Release Factor (PTRF) as a direct target gene of miR-217 in the SCC13 cell. In addition, PTRF expression was downregulated in the cSCCcSCC tissues. Moreover, we demonstrated that there was a significant inverse correlation between miR-217 and PTRF expression in the cSCCcSCC. Furthermore, overexpression of PTRF could rescue miR-217's oncogenic effect on cSCC. Therefore, these results suggested that upregulation of miR-217 could contribute to development of cSCCcSCC through targeting PTRF.

MiR-204 silencing in intraepithelial to invasive cutaneous squamous cell carcinoma progression

Background

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer and frequently progresses from an actinic keratosis (AK), a sun-induced keratinocyte intraepithelial neoplasia (KIN). Epigenetic mechanisms involved in the phenomenon of progression from AK to cSCC remain to be elicited.

Methods

Expression of microRNAs in sun-exposed skin, AK and cSCC was analysed by Agilent microarrays. DNA methylation of miR-204 promoter was determined by bisulphite treatment and pyrosequencing. Identification of miR-204 targets and pathways was accomplished in HaCat cells. Immunofluorescence and immunohistochemistry were used to analyze STAT3 activation and PTPN11 expression in human biopsies.

Results

cSCCs display a marked downregulation of miR-204 expression when compared to AK. DNA methylation of miR-204 promoter was identified as one of the repressive mechanisms that accounts for miR-204 silencing in cSCC. In HaCaT cells miR-204 inhibits STAT3 and favours the MAPK signaling pathway, likely acting through PTPN11, a nuclear tyrosine phosphatase that is a direct miR-204 target. In non-peritumoral AK lesions, activated STAT3, as detected by pY705-STAT3 immunofluorescence, is retained in the membrane and cytoplasm compartments, whereas AK lesions adjacent to cSCCs display activated STAT3 in the nuclei.

Conclusions

Our data suggest that miR-204 may act as a “rheostat” that controls the signalling towards the MAPK pathway or the STAT3 pathway in the progression from AK to cSCC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12943-016-0537-z) contains supplementary material, which is available to authorized users.

Circular RNA expression in cutaneous squamous cell carcinoma

BACKGROUND

CircularRNAs (circRNAs) are a reinvented class of abundant, stable, and evolutionary conserved non-coding RNAs with pivotal impacts on the cellular regulatory network and epigenetics by sequestering microRNAs (miRNAs) like a sponge.

OBJECTIVE

Purpose of the present study was to investigate circRNA expression in cutaneous squamous cell carcinoma (cSCC).

METHODS

A total of six cSCC and six non-lesional skin (control) biopsies were harvested. Microarray based circRNA expression was determined in the cSCC (n=3) and compared with the non-lesional skin (n=3) from a group of 13,617 distinct human circRNAs found in the Arraystar circRNA Array V2.0 (Arraystar, Rockville, USA). Microarray data were validated by quantitative real-time reverse transcription polymerase chain reaction in a separate group (cSCC, n=3 and non-lesional skin, n=3). miRNA binding to miRNA response elements (MREs) sequence data were acquired bioinformatically. Further data mining was performed to identify circRNAs containing MRE sequences that interacted with previously described miRNAs playing a role in cSCC formation.

RESULTS

A total of 322 circRNAs (143 up- and 179 down-regulated; fold change ≥2 and p<0.05) were identified as differentially expressed in cSCC. Furthermore, we identified a total of 1603 MREs that were part of the differentially expressed circRNAs. Among those circRNAs, a complementary MRE sequence was identified in 23 miRNAs previously known to be cSCC relevant.

CONCLUSION

This study showed that circRNAs are differentially expressed in cSCC and play an important role in tumor formation by interfering with cSCC relevant miRNAs through miRNA sequence complementary MREs participating in epigenetic control.

hsa-miR-29c and hsa-miR-135b differential expression as potential biomarker of gastric carcinogenesis

AIM

To investigate the expression profiles of hsa-miR-29c and hsa-miR-135b in gastric mucosal samples and their values as gastric carcinogenesis biomarkers.

METHODS

The expression levels of hsa-miR-29c and hsa-miR-135b in normal gastric mucosa, non-atrophic chronic gastritis, intestinal metaplasia and intestinal-type gastric adenocarcinoma were analysed using quantitative real-time PCR. The difference between hsa-miR-29c and hsa-miR-135b expression profiles in the grouped samples was evaluated by ANOVA and Student's t-test tests. The results were adjusted for multiple testing by using Bonferroni's correction. P values ≤ 0.05 were considered statistically significant. To evaluate hsa-miR-29c and hsa-miR-135b expressions as potential biomarkers of gastric carcinogenesis, we performed a receiver operating characteristic curve analysis and the derived area under the curve, and a Categorical Principal Components Analysis. In silico identification of the genetic targets of hsa-miR-29c and hsa-miR-135b was performed using different prediction tools, in order to identify possible genes involved in gastric carcinogenesis.

RESULTS

The expression levels of hsa-miR-29c were higher in normal gastric mucosal samples, and decreased progressively in non-atrophic chronic gastritis samples, intestinal metaplasia samples and intestinal-type gastric adenocarcinoma samples. The expression of hsa-miR-29c in the gastric lesions showed that non-atrophic gastritis have an intermediate profile to gastric normal mucosa and intestinal-type gastric adenocarcinoma, and that intestinal metaplasia samples presented an expression pattern similar to that in intestinal-type gastric adenocarcinoma. This microRNA (miRNA) has a good discriminatory accuracy between normal gastric samples and (1) intestinal-type gastric adenocarcinoma; and (2) intestinal metaplasia, and regulates the DMNT3A oncogene. hsa-miR-135b is up-regulated in non-atrophic chronic gastritis and intestinal metaplasia samples and down-regulated in normal gastric mucosa and intestinal-type gastric adenocarcinoma samples. Non-atrophic chronic gastritis and intestinal metaplasia are significantly different from normal gastric mucosa samples. hsa-miR-135b expression presented a greater discriminatory accuracy between normal samples and gastric lesions. This miRNA was associated with Helicobacter pylori presence in non-atrophic chronic gastritis samples and regulates the APC and KLF4 tumour suppressor genes.

CONCLUSION

Our results provide evidence of epigenetic alterations in non-atrophic chronic gastritis and intestinal metaplasia and suggest that hsa-miR-29c and hsa-miR-135b are promising biomarkers of gastric carcinogenesis.

Clinical significance of expression of miR-135b, LZTS1 and β-catenin in pancreatic cancer

AIM: To detect the expression of miR-135b, LZTS1 and β-catenin in pancreatic cancer in an attempt to explore their clinical significance.

METHODS: Locked nucleic acid in situ hybridization (ISH) and immunohisto-chemistry were used to detect the expression of miR-135b, LZTS1 and β-catenin proteins in 70 pancreatic cancer tissues and adjacent normal tissues, respectively.

RESULTS: The positive rate of miR-135b in pancreatic cancer was higher than that in adjacent tissues (71.4% vs 42.9%, P = 0.001). The positive rates of LZTS1 and β-catenin proteins in pancreatic cancer were significantly lower than those in adjacent tissues (34.3% vs 68.6%, 34.3% vs 74.3%, P < 0.05). Expression of miR-135b had a negative correlation with that of LZTS1 in pancreatic cancer (r = -0.61, P < 0.05), but miR-135b expression had no significant correlation with β-catenin (r = 0.06, P > 0.05). LZTS1 expression had a positive correlation with that of β-catenin (r = 0.37, P < 0.05). Expression of miR-135b, LZTS1 and β-catenin was closely related with lymph node metastasis and clinical stage (P < 0.05), but had no correlation with patient age, sex, tumor site or histological grade (P > 0.05).

CONCLUSION: miR-135b is highly expressed in pancreatic cancer, while the expression of LZTS1 and β-catenin is decreased. Up-regulated expression of miR-135b may participate in the development of pancreatic cancer by down-regulating the expression of LZTS1 protein.

Down-regulation of microRNA-135b inhibited growth of cervical cancer cells by targeting FOXO1

More and more evidence has confirmed that dysregulation of microRNAs (miRNAs) can conduce to the progression of human cancers. Previous studied have shown that dysregulation of miR-135b is in varieties of tumors. However, the roles of miR-135b in cervical cancer remain unknown. Therefore, our aim of this study was to explore the biological function and molecular mechanism of miR-135b in cervical cancer cell lines, discussing whether it could be a therapeutic biomarker of cervical cancer in the future. The MTT assay and ELISA-Brdu assay were used to assess cell proliferation. Cell cycle was detected by flow cytometry. Real-time quantitative polymerase chain reaction (PCR) and Western blot analyses were used to detect expressions of cyclin D1, p21, p27 and FOXO1. In our study, we found that miR-135b is up-regulated in cervical cancer cell lines. Down-regulation of miR-135b evidently inhibited proliferation and arrested cell cycle in cervical cancer cells. Bioinformatics analysis predicted that the FOXO1 was a potential target gene of miR-135b. Besides, miR-135b inhibition significantly increased expressions of the cyclin-dependent kinase inhibitors, p21(/CIP1) and p27(/KIP1), and decreased expression of cyclin D1. However, the high level of miR-135b was associated with increased expression of FOXO1 in cervical cancer cells. Further study by luciferase reporter assay demonstrated that miR-135b could directly target FOXO1. Down-regulation of FOXO1 in cervical cancer cells transfected with miR-135b inhibitor partially reversed its inhibitory effects. In conclusion, down-regulation of miR-135b inhibited cell growth in cervical cancer cells by up-regulation of FOXO1.