microRNA-10b enhances pancreatic cancer cell invasion by suppressing TIP30 expression and promoting EGF and TGF-β actions

Allicin: a promising modulator of apoptosis and survival signaling in cancer

According to the World Health Organization, cancer is the foremost cause of mortality globally. Various phytochemicals from natural sources have been extensively studied for their anticancer properties. Allicin, a powerful organosulfur compound derived from garlic, exhibits anticancer, antioxidant, anti-inflammatory, antifungal, and antibacterial properties. This review aims to update and evaluate the chemistry, composition, mechanisms of action, and pharmacokinetics Allicin. Allicin has garnered significant attention for its potential role in modulating Fas-FasL, Bcl2-Bax, PI3K-Akt-mTOR, autophagy, and miRNA pathways. At the molecular level, allicin induces the release of cytochrome c from the mitochondria and enhances the activation of caspases-3, -8, and -9. This is accompanied by the simultaneous upregulation of Bax and Fas expression in tumor cells. Allicin can inhibit excessive autophagy by activating the PI3K/Akt/mTOR and MAPK/ERK/mTOR signaling pathways. Allicin-loaded nano-formulations efficiently induce apoptosis in cancer cells while minimizing toxicity to normal cells. Safety and clinical aspects are meticulously scrutinized, providing insights into the tolerability and adverse effects associated with allicin administration, along with an overview of current clinical trials evaluating its therapeutic potential. In conclusion, this review underscores the promising prospects of allicin as a dietary-derived medicinal compound for cancer therapy. It emphasizes the need for further research to elucidate its precise mechanisms of action, optimize delivery strategies, and validate its efficacy in clinical settings.

circEIF3I facilitates the recruitment of SMAD3 to early endosomes to promote TGF-β signalling pathway-mediated activation of MMPs in pancreatic cancer

BACKGROUND

Among digestive tract tumours, pancreatic ductal adenocarcinoma (PDAC) shows the highest mortality trend. Moreover, although PDAC metastasis remains a leading cause of cancer-related deaths, the biological mechanism is poorly understood. Recent evidence demonstrates that circular RNAs (circRNAs) play important roles in PDAC progression.

METHODS

Differentially expressed circRNAs in normal and PDAC tissues were screened via bioinformatics analysis. Sanger sequencing, RNase R and actinomycin D assays were performed to confirm the loop structure of circEIF3I. In vitro and in vivo functional experiments were conducted to assess the role of circEIF3I in PDAC. MS2-tagged RNA affinity purification, mass spectrometry, RNA immunoprecipitation, RNA pull-down assay, fluorescence in situ hybridization, immunofluorescence and RNA-protein interaction simulation and analysis were performed to identify circEIF3I-interacting proteins. The effects of circEIF3I on the interactions of SMAD3 with TGFβRI or AP2A1 were measured through co-immunoprecipitation and western blotting.

RESULTS

A microarray data analysis showed that circEIF3I was highly expressed in PDAC cells and correlated with TNM stage and poor prognosis. Functional experiments in vitro and in vivo revealed that circEIF3I accelerated PDAC cells migration, invasion and metastasis by increasing MMPs expression and activity. Mechanistic research indicated that circEIF3I binds to the MH2 domain of SMAD3 and increases SMAD3 phosphorylation by strengthening the interactions between SMAD3 and TGFβRI on early endosomes. Moreover, AP2A1 binds with circEIF3I directly and promotes circEIF3I-bound SMAD3 recruitment to TGFβRI on early endosomes. Finally, we found that circEif3i exerts biological functions in mice similar to those of circEIF3I in humans PDAC.

CONCLUSIONS

Our study reveals that circEIF3I promotes pancreatic cancer progression. circEIF3I is a molecular scaffold that interacts with SMAD3 and AP2A1 to form a ternary complex, that facilitates the recruitment of SMAD3 to early endosomes and then activates the TGF-β signalling pathway. Hence, circEIF3I is a potential prognostic biomarker and therapeutic target in PDAC.

The Role of Krüppel-like Factors in Pancreatic Physiology and Pathophysiology

Krüppel-like factors (KLFs) belong to the family of transcription factors with three highly conserved zinc finger domains in the C-terminus. They regulate homeostasis, development, and disease progression in many tissues. It has been shown that KLFs play an essential role in the endocrine and exocrine compartments of the pancreas. They are necessary to maintain glucose homeostasis and have been implicated in the development of diabetes. Furthermore, they can be a vital tool in enabling pancreas regeneration and disease modeling. Finally, the KLF family contains proteins that act as tumor suppressors and oncogenes. A subset of members has a biphasic function, being upregulated in the early stages of oncogenesis and stimulating its progression and downregulated in the late stages to allow for tumor dissemination. Here, we describe KLFs' function in pancreatic physiology and pathophysiology.

microRNA Expression Profile of Purified Alveolar Epithelial Type II Cells

Alveolar type II (ATII) cells are essential for the maintenance of the alveolar homeostasis. However, knowledge of the expression of the miRNAs and miRNA-regulated networks which control homeostasis and coordinate diverse functions of murine ATII cells is limited. Therefore, we asked how miRNAs expressed in ATII cells might contribute to the regulation of signaling pathways. We purified "untouched by antibodies" ATII cells using a flow cytometric sorting method with a highly autofluorescent population of lung cells. TaqMan® miRNA low-density arrays were performed on sorted cells and intersected with miRNA profiles of ATII cells isolated according to a previously published protocol. Of 293 miRNAs expressed in both ATII preparations, 111 showed equal abundances. The target mRNAs of bona fide ATII miRNAs were used for pathway enrichment analysis. This analysis identified nine signaling pathways with known functions in fibrosis and/or epithelial-to-mesenchymal transition (EMT). In particular, a subset of 19 miRNAs was found to target 21 components of the TGF-β signaling pathway. Three of these miRNAs (miR-16-5p, -17-5p and -30c-5p) were down-modulated by TGF-β1 stimulation in human A549 cells, and concomitant up-regulation of associated mRNA targets (BMPR2, JUN, RUNX2) was observed. These results suggest an important role for miRNAs in maintaining the homeostasis of the TGF-β signaling pathway in ATII cells under physiological conditions.

Evaluation of miRNA-21-5p and miRNA-10b-5p levels in serum-derived exosomes of breast cancer patients in different grades

BACKGROUND & OBJECTIVES

Tumor cells have various effects and dominance over other healthy cells. Cancer cells alter the cell program in healthy cells by secreting exosomes containing microRNAs involved in epithelial-mesenchymal transition (EMT). They can migrate to distant organs and establish a pre-metastatic niche. The purpose of this study was to determine the expression of miRNA-21-5p and miRNA-10b-5p, both of which are involved in EMT, in breast cancer-derived exosomes of various grades in order to identify new biomarkers involved in breast cancer progression.

METHODS

In this study, a blood sample was taken from 60 patients with grades I, II, or III breast cancer, as well as twenty healthy individuals as a control group. The exosomes were then purified from serum samples, and their relative expression of miRNA-21-5p and miRNA-10b-5p was determined using the real-time PCR method.

RESULTS

miRNA-21-5p expression was significantly increased in patients with breast cancer grades I, II, and III compared to the control group (p < 0.01), (p < 0.0001) and (p < 0.0001), respectively, as was miRNA-10b-5p expression in patients with breast cancer grades I, II, and III compared to the control group (p < 0.0001), (p < 0.0001) and (p < 0.0001), respectively.

CONCLUSION

Our results show that both microRNAs increase as cells lose their differentiation and become more invasive, which is evidence of cancer progression. Hence, both microRNAs may have the potential to be used alone or in combination with other biomarkers for the diagnosis and prognosis of breast cancer.

TGFβ Signaling in the Pancreatic Tumor Microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is associated with poor clinical outcomes, largely attributed to incomplete responses to standard therapeutic approaches. Recently, selective inhibitors of the Transforming Growth Factor β (TGFβ) signaling pathway have shown early promise in the treatment of PDAC, particularly as a means of augmenting responses to chemo- and immunotherapies. However, TGFβ is a potent and pleiotropic cytokine with several seemingly paradoxical roles within the pancreatic tumor microenvironment (TME). Although TGFβ signaling can have potent tumor-suppressive effects in epithelial cells, TGFβ signaling also accelerates pancreatic tumorigenesis by enhancing epithelial-to-mesenchymal transition (EMT), fibrosis, and the evasion of the cytotoxic immune surveillance program. Here, we discuss the known roles of TGFβ signaling in pancreatic carcinogenesis, the biologic consequences of the genetic inactivation of select components of the TGFβ pathway, as well as past and present attempts to advance TGFβ inhibitors in the treatment of PDAC patients.

Suppression of miR-106a-5p expression inhibits tumorigenesis via increasing CELF-2 expression in spinal cord glioma

Spinal cord glioma is a tumor characterized by high recurrence and mortality rates, and its treatment remains a major challenge. It has been reported that abnormal expression of microRNAs (miRNAs/miRs) is associated with tumor progression. Therefore, the current study aimed to identify novel miRNAs associated with spinal cord glioma. Herein, the expression levels of several miRNAs were determined in human spinal cord glioma and adjacent non-cancerous tissues by reverse transcription-quantitative (RT-qPCR). The results revealed that miR-106a-5p expression was markedly upregulated in spinal cord glioma tissues compared with in non-cancerous tissues. Furthermore, the biological effects of miR-106a-5p on spinal cord glioma cells were evaluated by MTT, Transwell and flow cytometric assays. In 0231SCG cells transfected with miR-106a-5p inhibitor, cell proliferation, migration and invasion were attenuated, whereas apoptosis was enhanced. A search of the TargetScan database revealed that miR-106a-5p directly targeted CUGBP Elav-like family member 2 (CELF-2). Western blot and RT-qPCR experiments further confirmed the association between miR-106a-5p and CELF-2 expression in spinal cord glioma tissues. The current results demonstrated that CELF-2 was a direct target of miR-106a-5p, and that the expression levels of CELF-2 were negatively associated with those of miR-106a-5p. In addition, overexpression of CELF-2 in spinal cord glioma cells reversed the tumor-promoting effects of miR-106a-5p both in vitro and in vivo. Overall, the aforementioned findings indicated that miR-106a-5p, which was highly expressed in spinal cord glioma tissues, may affect the proliferation, migration, invasion and apoptosis of spinal cord glioma cells via targeting CELF-2, thus indicating a potential approach to the future clinical management of spinal cord glioma.

miR-3613-5p enhances the metastasis of pancreatic cancer by targeting CDK6

Pancreatic cancer (PC) is a leading cause of cancer mortality and is expected to continue increasing incidence. Abnormally expressed microRNAs have been demonstrated tightly correlated with the development and progression of PC. However, the molecular mechanisms remain largely unknown. In this study through combing both the TCGA database and our two verification PC cohorts, we found the consistent reduction of miR-3613-5p in PC tumors, which significantly correlated with reduced cumulative survival rate among PC patients. PC patients with higher lymph node metastasis rate show reduced miR-3613-5p expression. Through further mechanistic investigation, we demonstrate that miR-3613-5p down-regulated CDK6 in repressing the metastasis capacity of PC cells in vitro and in vivo. Elevated CDK6 were also found in PC samples, which also correlate with poor prognosis. Thus, our study found a novel tumor repressor miR-3613-5p in PC progression.

MicroRNA-1469-5p promotes the invasion and proliferation of pancreatic cancer cells via direct regulating the NDRG1/NF-κB/E-cadherin axis

Numerous studies demonstrated that microRNAs (miRNAs) were highly involved in pancreatic cancer development. However, the functional roles of many miRNAs remain elusive in pancreatic cancer. In the present study, we analyzed previous published microarray data and found that miR-1469-5p was one of top upregulated miRNAs in pancreatic tumors. Our further study showed that miR-1469-5p was highly expressed in collected pancreatic tumors and its upregulation was associated with lymph node metastasis and tumors of advanced TNM stage. Functional analysis with miR-1469-5p inhibitor showed that downregulation of miR-1469-5p repressed pancreatic cancer cell proliferation and invasion. Mechanistically, miR-1469-5p directly interacted with metastasis suppressor NDRG1 mRNA and downregulated expression of NDRG1 to activate NF-κB pathway in pancreatic cancer cells. It was also found that miR-1469-5p decreased expression of E-cadherin, a metastasis related gene repressed by NF-κB pathway, in pancreatic cancer cells. Transfection of NDRG1 small interference RNA (siRNA) attenuated the function of miR-1469-5p inhibitor in pancreatic cancer cells. Moreover, miR-1469-5p expression was negatively associated with NDRG1 and E-cadherin mRNA levels in pancreatic tumors. Taken together, miR-1469-5p may exert its oncogenic potential in pancreatic cancer via regulating a NDRG1/NF-κB/E-cadherin axis, suggesting that it may be clinically valuable as a prognostic biomarker of pancreatic cancer.

miR‑539 suppresses the proliferation, migration, invasion and epithelial mesenchymal transition of pancreatic cancer cells through targeting SP1

MicroRNA (miR)‑539 has inhibitory effects on certain types of cancer, but its role in pancreatic cancer (PCa) remains unclear. The present study investigated the effects of miR‑539 on PCa, and aimed to determine possible therapeutic targets for the treatment of PCa. The expression of miR‑539 in PCa tissues, paired normal adjacent tissues and PCa cell lines (CAPAN‑2, BxPC3, CFPAC1, SW1990 and PANC1), and human non‑cancerous pancreatic cells (hTRET‑HPNE) was determined and compared. The effects of upregulation and downregulation of miR‑539 on proliferation, apoptosis, cell cycle, invasion, migration and epithelial‑mesenchymal transition (EMT) of PCa cells were investigated. Additionally, the target gene of miR‑539 was predicted and its effects on PCa cells were further investigated. The results revealed low expression of miR‑539 in PCa tissues and cell lines. Additionally, increasing miR‑539 expression inhibited the proliferation, migration, invasion and EMT of PCa cells and induced apoptosis by blocking G1 phase of the cell cycle, while reducing miR‑539 expression had the opposite results. Furthermore, specificity protein 1 (SP1) was found to be the target gene of miR‑539. SP1 promoted the proliferation, migration, invasion and EMT transformation of PCa cells, but these effects were reversed by high expression of miR‑539. Additionally, miR‑539 suppressed the proliferation, metastasis, invasion and EMT transformation of PCa cells through targeting SP1. Therefore, miR‑539 overexpression may contribute toward development of novel therapeutic strategies for PCa in the future.

Elevated expression of exosomal microRNA-21 as a potential biomarker for the early diagnosis of pancreatic cancer using a tethered cationic lipoplex nanoparticle biochip

Pancreatic cancer (PC) has a poor prognosis due to the lack of effective molecular biomarkers for early diagnosis. Recent studies have investigated the use of exosomal microRNAs (exmiRs) as diagnostic biomarkers in cancer. The present study examined exmiR-21, exmiR-10b and exmiR-212-3p expression in patients with PC and healthy individuals. The expression levels of exmiR-21, exmiR-10b and exmiR-212-3p were examined in the peripheral blood plasma of 36 patients with PC and 65 healthy controls, using tethered cationic lipoplex nanoparticle biochip. The levels of exmiR-21 in the plasma of 34 mice were also evaluated. The expression levels of exmiR-21 and exmiR-10b were significantly greater in patients with PC compared with the control group. The receiver operating characteristic (ROC) analysis indicated that exmiR-21 had better diagnostic performance (P=0.0003; AUC, 0.7171) compared with the other two exmiRs. The diagnostic value of exmiR-21 improved when combined with exmiR-10b (P<0.0001; AUC, 0.791). Furthermore, exmiR-21 was capable of distinguishing patients with early-stage PC from controls and advanced-stage PC (P<0.05, early stage vs. healthy; P<0.001, early stage vs. advanced stage). The results of the present study revealed that the plasma levels of exmiR-21 and exmiR-10b were upregulated in patients with PC. The ROC analyses indicated that exmiR-21 had the best diagnostic performance among the three exmiRs. Furthermore, exmiR-21 was capable of discriminating patients with early-stage PC from healthy controls. These findings indicate the potential of determining the expression of exmiR-21 from serum using a tethered cationic lipoplex nanoparticle biochip as a novel non-invasive strategy for the early diagnosis of PC.

Effect and mechanism of microRNA-10b on proliferation and invasion of esophageal cancer cells

MicroRNA (miR)-10b is highly expressed in esophageal cancer tissues and is associated with poor prognosis of esophageal cancer. However, the role and mechanism of miR-10b in esophageal cancer cells remains unclear, therefore, the present study aimed to investigate this. Esophageal cancer cells, TE-1 and EC9706, were transfected with miR-10b mimic, miR-10b inhibitor or incubated with transforming growth factor-β (TGF-β). MTT and EdU assays were used to detect cell proliferation. Flow cytometry was used to determine cell cycle analysis and apoptosis. Cell migration and invasion were also analyzed. Western blot analysis was used to detect protein levels and reverse transcription-quantitative PCR was used to analyze miR-10b expression. The present results demonstrated that, compared with the control group, miR-10b significantly promoted TE-1 and EC9706 cell proliferation. Compared with miR-10b inhibitor group and control group, miR-10b mimic promoted esophageal cancer cell cycle progression, inhibited apoptosis of esophageal cancer cells and promoted the migration and invasion of cells. The proliferation of esophageal cancer cells increased in a dose-dependent manner with TGF-β concentration. TGF-β treatment induced high expression of miR-10b in both cell lines. The miR-10b mimic + TGF-β group further promoted the migration and invasion of esophageal cancer cells. Western blot analysis determined that, compared with the control group, miR-10b mimic increased TGF-β expression. miR-10b mimic also inhibited the expression of phosphatase and tensin homolog (PTEN) in tumor cells. Compared with the control group, TGF-β inhibited the expression of PTEN with the miR-10b mimic + TGF-β group further inhibiting the PTEN. miR-10b inhibitor + TGF-β reversed the effect of TGF-β and miR-10b on PTEN. In conclusion, miR-10b promoted cell cycle progression, inhibited apoptosis and promoted the migration and invasion of esophageal cancer cells. The mechanism may be related to the upregulation of TGF-β and the downregulation of PTEN. The present findings suggested that miR-10b might be a potential therapeutic target for esophageal cancer.

A microRNA signature in circulating exosomes is superior to exosomal glypican-1 levels for diagnosing pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a deadly malignancy that often presents clinically at an advanced stage and that may be confused with chronic pancreatitis (CP). Conversely, CP may be misdiagnosed as PDAC leading to unwarranted pancreas resection. Therefore, early PDAC diagnosis and clear differentiation between PDAC and CP are crucial for improved care. Exosomes are circulating microvesicles whose components can serve as cancer biomarkers. We compared exosomal glypican-1 (GPC1) and microRNA levels in normal control subjects and in patients with PDAC and CP. We report that exosomal GPC1 is not diagnostic for PDAC, whereas high exosomal levels of microRNA-10b, (miR-10b), miR-21, miR-30c, and miR-181a and low miR-let7a readily differentiate PDAC from normal control and CP samples. By contrast with GPC1, elevated exosomal miR levels decreased to normal values within 24 h following PDAC resection. All 29 PDAC cases exhibited significantly elevated exosomal miR-10b and miR-30c levels, whereas 8 cases had normal or slightly increased CA 19-9 levels. Thus, our exosomal miR signature is superior to exosomal GPC1 or plasma CA 19-9 levels in establishing a diagnosis of PDAC and differentiating between PDAC and CP.

MicroRNA Expression in a Readily Accessible Common Hepatic Artery Lymph Node Predicts Time to Pancreatic Cancer Recurrence Postresection

Lymph node involvement in pancreatic adenocarcinoma (PAC) predicts postresection survival, but early lymph node metastasis detection is not easily accomplished. We assessed a panel of microRNAs (miRNAs) in a common hepatic artery lymph node (station 8) that is readily accessible during pancreatoduodenectomy (PD) to determine if increased miRNA levels correlate with postresection recurrence. Station 8 lymph nodes overlying the common hepatic artery collected during PD were assayed for miRNA-10b, miRNA-30c, miRNA-21, and miRNA-155 and cytokeratin-19 (CK19), an epithelial cell marker, using quantitative PCR. Expression was correlated with disease recurrence, recurrence-free survival (RFS), and overall survival (OS). Station 8 lymph nodes from 37 patients (30 periampullary carcinomas (PCs), 2 chronic pancreatitis, 5 other cancers) exhibited increased miRNA-10b levels in 14/30 PCs, and in 10 of these 14 patients, cancer recurred during the study period (2012-2015). High miRNA-10b was also associated with shorter RFS (42.5 vs. 92.4 weeks, p < 0.05) but not OS, whereas miRNA-30c, miRNA-21, and miRNA-155 levels and CK19 mRNA levels in station 8 nodes were variable and did not correlate with RFS or OS. We conclude that elevated miRNA-10b levels in station 8 lymph nodes could be utilized to assess risk for early disease progression in patients with periampullary tumors.

MiR-9 and miR-21 as prognostic biomarkers for recurrence in papillary thyroid cancer

Despite low mortality rates, nodal recurrence in papillary thyroid carcinoma occurs in up to 20 % of patients. Emerging evidences indicate that dysregulated microRNAs are implicated in the process of metastasis. In the present study, we investigated whether miR-9, miR-10b, miR-21 and miR-146b levels are predictive of papillary thyroid carcinoma recurrence. Using macro-dissection followed by quantitative real-time PCR, we measured miR-9, miR-10b, miR-21 and miR-146b expression levels in formalin-fixed, paraffin-embedded samples of 66 patients with papillary thyroid carcinoma categorized into two groups: the recurrent group (n = 19) and the non-recurrent group (n = 47). All patients underwent total thyroidectomy and were followed for at least 120 months after surgery to be considered recurrence-free. Univariate and multivariate analysis were performed using the Cox proportional hazard model in order to identify associations between multiple clinical variables and microRNA expression levels and papillary thyroid carcinoma recurrence. MiR-9 and miR-21 expression levels were found to be significant prognostic factors for recurrence in patients with papillary thyroid carcinoma (HR = 1.48; 95 % CI 1.24-1.77, p < 0.001; and HR = 1.52; 95 % CI 1.18-1.94, p = 0.001; respectively). Multivariate analysis involving the expression level of miR-9 and miR-21 and various clinical parameters identified the expression of these microRNAs as independent prognostic factors for papillary thyroid cancer patients. In conclusion, our results support the potential clinical value of miR-9 and miR-21 as prognostic biomarkers for recurrence in papillary thyroid carcinoma.

Involvement of epithelial to mesenchymal transition in the development of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an intractable disease as a result of its rapid dissemination and resistance to conventional chemotherapy and radiotherapy. Surgical resection is the only curative therapy, but most of the tumors are unresectable at the time of diagnosis. The molecular mechanisms underlying the biological aggressiveness of this tumor type remain to be clarified. Epithelial to mesenchymal transition (EMT) is a developmental process that leads the phenotype shift from an epithelial morphology to a motile, fibroblast-like morphology. Recent studies showed that EMT is involved in the invasion and metastasis of many types of carcinomas including PDAC. In addition, PDAC cells with the EMT phenotype also exhibit chemoresistance and the cancer stem cell property. Various factors such as cytokines, growth factors, or transcriptional factors were found to promote the EMT program in PDAC cells. In this review, we summarize the current knowledge about the EMT in PDAC cells, focusing on the involvement of this process and its regulatory molecules including microRNA during the development of PDAC cells.

Global epigenetic regulation of microRNAs in multiple myeloma

Epigenetic changes frequently occur during tumorigenesis and DNA hypermethylation may account for the inactivation of tumor suppressor genes in cancer cells. Studies in Multiple Myeloma (MM) have shown variable DNA methylation patterns with focal hypermethylation changes in clinically aggressive subtypes. We studied global methylation patterns in patients with relapsed/refractory MM and found that the majority of methylation peaks were located in the intronic and intragenic regions in MM samples. Therefore, we investigated the effect of methylation on miRNA regulation in MM. To date, the mechanism by which global miRNA suppression occurs in MM has not been fully described. In this study, we report hypermethylation of miRNAs in MM and perform confirmation in MM cell lines using bisulfite sequencing and methylation-specific PCR (MSP) in the presence or absence of the DNA demethylating agent 5-aza-2'-deoxycytidine. We further characterized the hypermethylation-dependent inhibition of miR-152, -10b-5p and -34c-3p which was shown to exert a putative tumor suppressive role in MM. These findings were corroborated by the demonstration that the same miRNAs were down-regulated in MM patients compared to healthy individuals, alongside enrichment of miR-152-, -10b-5p, and miR-34c-3p-predicted targets, as shown at the mRNA level in primary MM cells. Demethylation or gain of function studies of these specific miRNAs led to induction of apoptosis and inhibition of proliferation as well as down-regulation of putative oncogene targets of these miRNAs such as DNMT1, E2F3, BTRC and MYCBP. These findings provide the rationale for epigenetic therapeutic approaches in subgroups of MM.

Up-regulation of microRNA-10b is associated with the development of breast cancer brain metastasis

Brain metastases from primary breast cancer are difficult to treat and associated with poor prognosis. Our understanding of the molecular basis for the development of such cancers is sparse. We hypothesized that the pro-metastatic microRNA-10b (miR-10b) plays a role in breast cancer brain metastasis. The study cohort comprised of twenty patients with breast cancer and brain metastasis as well as ten control patients (age, stage, and follow-up matched) with breast cancer without brain metastasis. All cases were microscopically reviewed to select tumor blocks with >50% tumor cells. RNA was extracted from formalin fixed paraffin embedded (FFPE) tumor tissue blocks. Expression of miR-10b was analyzed using qRT-PCR. The relevance of miR-10b expression was also tested using human breast cancer cell lines. An increased expression of miR-10b was noted in the primary breast cancer specimens of patients who subsequently developed brain metastasis, compared to those who did not. miR-10b also increased the invasive potential of breast cancer cells in vitro. Wilcoxon signed rank test revealed a statistically significant difference between the paired tumors from breast cancers and brain metastasis (p <0.001). Increased expression of miR-10b appears to be associated with breast cancer brain metastasis. These findings are clinically relevant since miR-10b could serve as a prognostic and/or therapeutic target for anti-metastatic therapy. Identifying molecular signatures of primary breast cancers which have a propensity for brain metastasis is critical for designing novel therapies to counter the development of brain metastasis in patients diagnosed with breast cancer.

MicroRNA-10b overexpression promotes non-small cell lung cancer cell proliferation and invasion

BACKGROUND

miRNAs are a class of small non-coding RNA molecules that play an important role in the pathogenesis of human diseases through negative regulation of gene expression. Although miRNA-10b (miR-10b) has been implicated in other tumors, its role in non-small cell lung cancer (NSCLC) is still unknown. The aim of the present study was to investigate the role of miR-10b in NSCLC.

METHODS

Expression of miR-10b was analyzed in NSCLC cell line A549 by qRT-PCR. Cell viability was evaluated using Cell Counting Kit (CCK)-8. Cell migration and invasion were evaluated by wound healing assay and transwell assays. Cell cycle and apoptosis analyses were performed. Western blotting was used to predicate the target of miR-10b.

RESULTS

The A549 cell line transfected with the miR-10b exhibited significantly increased proliferation, migration, and invasion capacities when compared with the control cells (P < 0.05). Krüppel-like factor 4 (KLF4) may be indirectly targeted by miR-10b during the proliferation increasing of A549 cells.

CONCLUSION

In this study, we found that miR-10b is a tumor enhancer in NSCLC. Thus, miR-10b may represent a potential therapeutic target for NSCLC intervention.