MiR-200b and miR-15b regulate chemotherapy-induced epithelial-mesenchymal transition in human tongue cancer cells by targeting BMI1

PI3K/AKT pathway as a pivotal regulator of epithelial-mesenchymal transition in lung tumor cells

Lung cancer, as the leading cause of cancer related deaths, is one of the main global health challenges. Despite various progresses in diagnostic and therapeutic methods, there is still a high rate of mortality among lung cancer patients, which can be related to the lack of clinical symptoms to differentiate lung cancer from the other chronic respiratory disorders in the early tumor stages. Most lung cancer patients are identified in advanced and metastatic tumor stages, which is associated with a poor prognosis. Therefore, it is necessary to investigate the molecular mechanisms involved in lung tumor progression and metastasis in order to introduce early diagnostic markers as well as therapeutic targets. Epithelial-mesenchymal transition (EMT) is considered as one of the main cellular mechanisms involved in lung tumor metastasis, during which tumor cells gain the metastatic ability by acquiring mesenchymal characteristics. Since, majority of the oncogenic signaling pathways exert their role in tumor cell invasion by inducing the EMT process, in the present review we discussed the role of PI3K/AKT signaling pathway in regulation of EMT process during lung tumor metastasis. It has been reported that the PI3K/AKT acts as an inducer of EMT process through the activation of EMT-specific transcription factors in lung tumor cells. MicroRNAs also exerted their inhibitory effects during EMT process by inhibition of PI3K/AKT pathway. This review can be an effective step towards introducing the PI3K/AKT pathway as a suitable therapeutic target to inhibit the EMT process and tumor metastasis in lung cancer patients.

EM-transcriptomic signature predicts drug response in advanced stages of high-grade serous ovarian carcinoma based on ascites-derived primary cultures

Introduction: High-grade serous ovarian carcinoma (HGSOC) remains a medical challenge despite considerable improvements in the treatment. Unfortunately, over 75% of patients have already metastasized at the time of diagnosis. Advances in understanding the mechanisms underlying how ascites cause chemoresistance are urgently needed to derive novel therapeutic strategies. This study aimed to identify the molecular markers involved in drug sensitivity and highlight the use of ascites as a potential model to investigate HGSOC treatment options. Methods: After conducting an in silico analysis, eight epithelial-mesenchymal (EM)-associated genes related to chemoresistance were identified. To evaluate differences in EM-associated genes in HGSOC samples, we analyzed ascites-derived HGSOC primary cell culture (AS), tumor (T), and peritoneal nodule (NP) samples. Moreover, in vitro experiments were employed to measure tumor cell proliferation and cell migration in AS, following treatment with doxorubicin (DOX) and cisplatin (CIS) and expression of these markers. Results: Our results showed that AS exhibits a mesenchymal phenotype compared to tumor and peritoneal nodule samples. Moreover, DOX and CIS treatment leads to an invasive-intermediate epithelial-to-mesenchymal transition (EMT) state of the AS by different EM-associated marker expression. For instance, the treatment of AS showed that CDH1 and GATA6 decreased after CIS exposure and increased after DOX treatment. On the contrary, the expression of KRT18 has an opposite pattern. Conclusion: Taken together, our study reports a comprehensive investigation of the EM-associated genes after drug exposure of AS. Exploring ascites and their associated cellular and soluble components is promising for understanding the HGSOC progression and treatment response at a personalized level.

Decoding the role of miRNAs in oral cancer pathogenesis: A focus on signaling pathways

Oral cancer (OC) is the predominant type originating in the head and neck region. The incidence of OC is mostly associated with behavioral risk factors, including tobacco smoking and excessive alcohol intake. Additionally, there is a lower but still significant association with viral infections such as human papillomaviruses and Epstein-Barr viruses. Furthermore, it has been observed that heritable genetic variables are linked to the risk of OC, in addition to the previously mentioned acquired risk factors. The current absence of biomarkers for OC diagnosis contributes to the frequent occurrence of advanced-stage diagnoses among patients. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs, and circular RNAs, have been observed to exert a significant effect on the transcriptional control of target genes involved in cancer, either through direct or indirect mechanisms. miRNAs are a class of short ncRNAs that play a role in regulating gene expression by enabling mRNA degradation or translational repression at the post-transcriptional phase. miRNAs are known to play a fundamental role in the development of cancer and the regulation of oncogenic cell processes. Notch signaling, PTEN/Akt/mTOR axis, KRAS mutation, JAK/STAT signaling, P53, EGFR, and the VEGFs have all been linked to OC, and miRNAs have been shown to have a role in all of these. The dysregulation of miRNA has been identified in cases of OC and is linked with prognosis.

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

Inhibition of epithelial-to-mesenchymal transition augments antitumor efficacy of nanotherapeutics in pancreatic ductal adenocarcinoma

Intrinsic drug resistance mechanisms of tumor cells often reduce intracellular drug concentration to suboptimal levels. Epithelial-to-mesenchymal transition (EMT) is a pivotal process in tumor progression and metastasis that confers an aggressive phenotype as well as resistance to chemotherapeutics. Therefore, it is imperative to develop novel strategies and identify new targets to improve the overall efficacy of cancer treatment. We developed SN38 (active metabolite of irinotecan)-assembled glycol chitosan nanoparticles (cSN38) for the treatment of pancreatic ductal adenocarcinoma (PDAC). Furthermore, cSN38 and the TGF-β1 inhibitor LY364947 formed composite nanoparticles upon self-assembly (cSN38 + LY), which obviated the poor aqueous solubility of LY364947 and enhanced drug sensitivity. The therapeutic efficacy of cSN38 + LY nanotherapeutics was studied in vitro and in vivo using suitable models. The cSN38 nanoparticles exhibited an antitumor effect that was significantly attenuated by TGF-β-induced EMT. The cellular uptake of SN38 was impeded during EMT, which affected the therapeutic efficacy. The combination of LY364947 and cSN38 markedly enhanced the cellular uptake of SN38, increased cytotoxic effects, and inhibited EMT in PDAC cells in vitro. Furthermore, cSN38 + LY significantly inhibited PDAC xenograft growth in vivo. The cSN38 + LY nanoparticles increased the therapeutic efficacy of cSN38 via repressing the EMT of PDAC cells. Our findings provide a rationale for designing nanoscale therapeutics to combat PDAC.

MiRNA-related metastasis in oral cancer: moving and shaking

Across the world, oral cancer is a prevalent tumor. Over the years, both its mortality and incidence have grown. Oral cancer metastasis is a complex process involving cell invasion, migration, proliferation, and egress from cancer tissue either by lymphatic vessels or blood vessels. MicroRNAs (miRNAs) are essential short non-coding RNAs, which can act either as tumor suppressors or as oncogenes to control cancer development. Cancer metastasis is a multi-step process, in which miRNAs can inhibit or stimulate metastasis at all stages, including epithelial-mesenchymal transition, migration, invasion, and colonization, by targeting critical genes in these pathways. On the other hand, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), two different types of non-coding RNAs, can regulate cancer metastasis by affecting gene expression through cross-talk with miRNAs. We reviewed the scientific literature (Google Scholar, Scopus, and PubMed) for the period 2000-2023 to find reports concerning miRNAs and lncRNA/circRNA-miRNA-mRNA networks, which control the spread of oral cancer cells by affecting invasion, migration, and metastasis. According to these reports, miRNAs are involved in the regulation of metastasis pathways either by directly or indirectly targeting genes associated with metastasis. Moreover, circRNAs and lncRNAs can induce or suppress oral cancer metastasis by acting as competing endogenous RNAs to inhibit the effect of miRNA suppression on specific mRNAs. Overall, non-coding RNAs (especially miRNAs) could help to create innovative therapeutic methods for the control of oral cancer metastases.

MiR-297 inhibits tumour progression of liver cancer by targeting PTBP3

Whereas increasing evidences demonstrate that miR-297 contributes to the tumour development and progression, the role of miR-297 and its underlying molecular mechanisms in hepatocellular carcinoma (HCC) was still unclear. Here, we reported that the expression of miR-297 increased significantly in hepG2 cells after the treatment of the conditioned medium of human amniotic epithelial cells(hAECs) which can inhibit the proliferation and migration of hepG2. And the overexpression of miR-297 inhibits the cell proliferation, migration and invasion of HCC cell lines in vitro and suppressed the tumorigenesis of HCC in vivo. Polypyrimidine tract-binding protein 3 (PTBP3) was identified as a direct target gene of miR-297 in HCC cell lines, and mediated the function of miR-297 in HCC cells. In clinical samples, miR-297 levels have a tendency to decrease, but there are no statistically significant differences. Furthermore, in vitro cell experiments confirmed that overexpression of miR-297 could inhibit the PI3K/AKT signaling pathway by down-regulating PTBP3 expression, thereby inhibiting the proliferation, migration and invasion of HCC cells. In conclusion, our results revealed that miR-297 could down-regulate the expression of PTBP3 and inhibit the activation of PI3K/AKT signaling pathway, thereby preventing HCC growth, migration and invasion.

MicroRNAs as the pivotal regulators of cisplatin resistance in head and neck cancers

Although, there is a high rate of good prognosis in early stage head and neck tumors, about half of these tumors are detected in advanced stages with poor prognosis. A combination of chemotherapy, radiotherapy, and surgery is the treatment option in head and neck cancer (HNC) patients. Although, cisplatin (CDDP) as the first-line drug has a significant role in the treatment of HNC patients, CDDP resistance can be observed in a large number of these patients. Therefore, identification of the molecular mechanisms involved in CDDP resistance can help to reduce the side effects and also provides a better therapeutic management. MicroRNAs (miRNAs) as the post-transcriptional regulators play an important role in drug resistance. Therefore, in the present review we investigated the role of miRNAs in CDDP response of head and neck tumors. It has been reported that the miRNAs exerted their roles in CDDP response by regulation of signaling pathways such as WNT, NOTCH, PI3K/AKT, TGF-β, and NF-kB as well as apoptosis, autophagy, and EMT process. The present review paves the way to suggest a non-invasive miRNA based panel marker for the prediction of CDDP response among HNC patients. Therefore, such diagnostic miRNA based panel marker reduces the CDDP side effects and improves the clinical outcomes of these patients following an efficient therapeutic management.

miRNAs as potential game-changers in head and neck cancer: Future clinical and medicinal uses

Head and neck cancers (HNCs) are a group of heterogeneous tumors formed most frequently from epithelial cells of the larynx, lips, oropharynx, nasopharynx, and mouth. Numerous epigenetic components, including miRNAs, have been demonstrated to have an impact on HNCs characteristics like progression, angiogenesis, initiation, and resistance to therapeutic interventions. The miRNAs may control the production of numerous genes linked to HNCs pathogenesis. The roles that miRNAs play in angiogenesis, invasion, metastasis, cell cycle, proliferation, and apoptosis are responsible for this impact. The miRNAs also have an impact on crucial HNCs-related mechanistic networks like the WNT/β-catenin signaling, PTEN/Akt/mTOR pathway, TGFβ, and KRAS mutations. miRNAs may affect how the HNCs respond to treatments like radiation and chemotherapy in addition to pathophysiology. This review aims to demonstrate the relationship between miRNAs and HNCs with a particular emphasis on how miRNAs impact HNCs signaling networks.

A 3D, Compartmental Tumor-Stromal Microenvironment Model of Patient-Derived Bone Metastasis

Bone is a frequent site of tumor metastasis. The bone-tumor microenvironment is heterogeneous and complex in nature. Such complexity is compounded by relations between metastatic and bone cells influencing their sensitivity/resistance to chemotherapeutics. Standard chemotherapeutics may not show efficacy for every patient, and new therapeutics are slow to emerge, owing to the limitations of existing 2D/3D models. We previously developed a 3D interface model for personalized therapeutic screening, consisting of an electrospun poly lactic acid mesh activated with plasma species and seeded with stromal cells. Tumor cells embedded in an alginate-gelatin hydrogel are overlaid to create a physiologic 3D interface. Here, we applied our 3D model as a migration assay tool to verify the migratory behavior of different patient-derived bone metastasized cells. We assessed the impact of two different chemotherapeutics, Doxorubicin and Cisplatin, on migration of patient cells and their immortalized cell line counterparts. We observed different migratory behaviors and cellular metabolic activities blocked with both Doxorubicin and Cisplatin treatment; however, higher efficiency or lower IC50 was observed with Doxorubicin. Gene expression analysis of MDA-MB231 that migrated through our 3D hybrid model verified epithelial-mesenchymal transition through increased expression of mesenchymal markers involved in the metastasis process. Our findings indicate that we can model tumor migration in vivo, in line with different cell characteristics and it may be a suitable drug screening tool for personalized medicine approaches in metastatic cancer treatment.

CD33 ‐targeting extracellular vesicles deliver antisense oligonucleotides against FLT3‐ITD and miR ‐125b for specific treatment of acute myeloid leukaemia

Introduction

Acute Myeloid Leukaemia (AML) is the most common blood cancer in adults. Although 2 out of 3 AML patients go into total remission after chemotherapies and targeted therapies, the disease recurs in 60%–65% of younger adult patients within 3 years after diagnosis with a dramatically decreased survival rate. Therapeutic oligonucleotides are promising treatments under development for AML as they can be designed to silence oncogenes with high specificity and flexibility. However, there are not many well validated approaches for safely and efficiently delivering oligonucleotide drugs. This issue could be resolved by utilizing a new generation of delivery vehicles such as extracellular vesicles (EVs).

Methods

In this study, we harness red blood cell‐derived EVs (RBCEVs) and engineer them via exogenous drug loading and surface functionalization to develop an efficient drug delivery system for AML. Particularly, EVs are designed to target CD33, a common surface marker with elevated expression in AML cells via the conjugation of a CD33‐binding monoclonal antibody onto the EV surface.

Results

The conjugation of RBCEVs with the CD33‐binding antibody significantly increases the uptake of RBCEVs by CD33‐positive AML cells, but not by CD33‐negative cells. We also load CD33‐targeting RBCEVs with antisense oligonucleotides (ASOs) targeting FLT3‐ITD or miR‐125b, 2 common oncogenes in AML, and demonstrate that the engineered EVs improve leukaemia suppression in in vitro and in vivo models of AML.

Conclusion

Targeted RBCEVs represent an innovative, efficient, and versatile delivery platform for therapeutic ASOs and can expedite the clinical translation of oligonucleotide drugs for AML treatments by overcoming current obstacles in oligonucleotide delivery.

A transistor-like pH-sensitive nanodetergent for selective cancer therapy

Plasma membrane rupture is a promising strategy for drug-resistant cancer treatment, but its application is limited by the low tumour selectivity of membranolytic molecules. Here we report the design of 'proton transistor' nanodetergents that can convert the subtle pH perturbation signals of tumour tissues into sharp transition signals of membranolytic activity for selective cancer therapy. Our top-performing 'proton transistor' nanodetergent, P(C6-Bn₂₀), can achieve a >32-fold change in cytotoxicity with a 0.1 pH input signal. At physiological pH, P(C6-Bn₂₀) self-assembles into neutral nanoparticles with inactive membranolytic blocks shielded by poly(ethylene glycol) shells, exhibiting low toxicity. At tumour acidity, a sharp transition in its protonation state induces a morphological transformation and an activation of the membranolytic blocks, and the cation-π interaction facilitates the insertion of benzyl groups-containing hydrophobic domains into the cell membranes, resulting in potent membranolytic activity. P(C6-Bn₂₀) is well tolerated in mice and shows high anti-tumour efficacy in various mouse tumour models.

Contribution of MicroRNAs in Chemoresistance to Cisplatin in the Top Five Deadliest Cancer: An Updated Review

Cisplatin (DDP) is a well-known anticancer drug used for the treatment of numerous human cancers in solid organs, including bladder, breast, cervical, head and neck squamous cell, ovarian, among others. Its most important mode of action is the DNA-platinum adducts formation, inducing DNA damage response, silencing or activating several genes to induce apoptosis; these mechanisms result in genetics and epigenetics modifications. The ability of DDP to induce tumor cell death is often challenged by the presence of anti-apoptotic regulators, leading to chemoresistance, wherein many patients who have or will develop DDP-resistance. Cancer cells resist the apoptotic effect of chemotherapy, being a problem that severely restricts the successful results of treatment for many human cancers. In the last 30 years, researchers have discovered there are several types of RNAs, and among the most important are non-coding RNAs (ncRNAs), a class of RNAs that are not involved in protein production, but they are implicated in gene expression regulation, and representing the 98% of the human genome non-translated. Some ncRNAs of great interest are long ncRNAs, circular RNAs, and microRNAs (miRs). Accumulating studies reveal that aberrant miRs expression can affect the development of chemotherapy drug resistance, by modulating the expression of relevant target proteins. Thus, identifying molecular mechanisms underlying chemoresistance development is fundamental for setting strategies to improve the prognosis of patients with different types of cancer. Therefore, this review aimed to identify and summarize miRs that modulate chemoresistance in DDP-resistant in the top five deadliest cancer, both in vitro and in vivo human models.

TRPM2-AS promotes the malignancy of osteosarcoma cells by targeting miR-15b-5p/PPM1D axis

Osteosarcoma (OS) is a malignant tumor with a low survival rate and a high incidence rate worldwide. Although research has reported the involvement of long non-coding RNAs (lncRNAs) in the pathogenesis of OS cells, the role of TRPM2-AS, miR-15b-5p, and PPM1D in OS progression remains unclear. This study aimed to examine the interaction of the TRPM2-AS/miR-15b-5p/PPM1D axis in OS cells to gain new insights into the molecular mechanism and pathogenesis of OS. After performing in vitro functional assays, we discovered that TRPM2-AS was overexpressed in OS cells. TRPM2-AS silencing impaired OS cell viability, proliferation, and migration, while it induced apoptosis in OS cells in vitro. Our experimental analysis also revealed that PPM1D is a direct target of miR-15b-5p. TRPM2-AS silencing was found to reverse the tumorigenic effect of the miR-15b-5p inhibitor, while the miR-15b-5p inhibitor restored the inhibition of OS caused by silencing PPM1D. Moreover, our findings revealed that miR-15b-5p exerted its tumor-suppressive role by directly targeting PPM1D. In conclusion, this study suggests that TRPM2-AS could promote OS cell malignancy by sponging miR-15b-5p/PPM1D axis.

Impact of Non-Coding RNAs on Chemotherapeutic Resistance in Oral Cancer

Drug resistance in oral cancer is one of the major problems in oral cancer therapy because therapeutic failure directly results in tumor recurrence and eventually in metastasis. Accumulating evidence has demonstrated the involvement of non-coding RNAs (ncRNAs), such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), in processes related to the development of drug resistance. A number of studies have shown that ncRNAs modulate gene expression at the transcriptional or translational level and regulate biological processes, such as epithelial-to-mesenchymal transition, apoptosis, DNA repair and drug efflux, which are tightly associated with drug resistance acquisition in many types of cancer. Interestingly, these ncRNAs are commonly detected in extracellular vesicles (EVs) and are known to be delivered into surrounding cells. This intercellular communication via EVs is currently considered to be important for acquired drug resistance. Here, we review the recent advances in the study of drug resistance in oral cancer by mainly focusing on the function of ncRNAs, since an increasing number of studies have suggested that ncRNAs could be therapeutic targets as well as biomarkers for cancer diagnosis.

MiR-15p-5p Mediates the Coordination of ICAM-1 and FAK to Promote Endothelial Cell Proliferation and Migration

Intercellular adhesion molecule-1 (ICAM-1) in endothelial cells is critical for neutrophil adhesion and transmigration across the endothelium. Focal adhesion kinase (FAK), which controls the turnover of focal adhesion to regulate cell adhesion and migration, plays a role in the resolution of inflammation. However, the coordinated involvement of ICAM-1 and FAK during endothelial inflammation has yet to be elucidated. This study reports that, as part of an inflammatory response, ICAM-1 controls FAK expression in endothelial cells via the microRNA miR-15b-5p. Induction of lung injury by lipopolysaccharide (LPS) resulted in higher levels of FAK expression in inflammatory tissues, while in ICAM-1 knockout mice, FAK expression was reduced in the lungs. FAK expression was also reduced in endothelial cells following ICAM-1 siRNA downregulation. Furthermore, ICAM-1 inhibited miR-15b-5p expression while increasing FAK mRNA and protein expression via binding of miR-15b-5p to the 3' untranslated region (UTR) of FAK. ICAM-1 inhibited miR-15b-5p promoter activity and hence reduced miR-15b-5p expression. FAK increased endothelial cell proliferation and migration, whereas miR-15b-5p inhibited cell proliferation and migration. These findings indicate that the inflammatory molecule ICAM-1 regulates FAK expression via miR-15b-5p levels, which in turn controls endothelial cell proliferation and migration.

Mining sponge phenomena in RNA expression data

In the last few years, the interactions among competing endogenous RNAs (ceRNAs) have been recognized as a key post-transcriptional regulatory mechanism in cell differentiation, tissue development, and disease. Notably, such sponge phenomena substracting active microRNAs from their silencing targets have been recognized as having a potential oncosuppressive, or oncogenic, role in several cancer types. Hence, the ability to predict sponges from the analysis of large expression data sets (e.g. from international cancer projects) has become an important data mining task in bioinformatics. We present a technique designed to mine sponge phenomena whose presence or absence may discriminate between healthy and unhealthy populations of samples in tumoral or normal expression data sets, thus providing lists of candidates potentially relevant in the pathology. With this aim, we search for pairs of elements acting as ceRNA for a given miRNA, namely, we aim at discovering miRNA-RNA pairs involved in phenomena which are clearly present in one population and almost absent in the other one. The results on tumoral expression data, concerning five different cancer types, confirmed the effectiveness of the approach in mining interesting knowledge. Indeed, 32 out of 33 miRNAs and 22 out of 25 protein-coding genes identified as top scoring in our analysis are corroborated by having been similarly associated with cancer processes in independent studies. In fact, the subset of miRNAs selected by the sponge analysis results in a significant enrichment of annotation for the KEGG32 pathway "microRNAs in cancer" when tested with the commonly used bioinformatic resource DAVID. Moreover, often the cancer datasets where our sponge analysis identified a miRNA as top scoring match the one reported already in the pertaining literature.

Head and Neck Cancers Are Not Alike When Tarred with the Same Brush: An Epigenetic Perspective from the Cancerization Field to Prognosis

Simple Summary

Squamous cell carcinomas affect different head and neck subsites and, although these tumors arise from the same epithelial lining and share risk factors, they differ in terms of clinical behavior and molecular carcinogenesis mechanisms. Differences between HPV-negative and HPV-positive tumors are those most frequently explored, but further data suggest that the molecular heterogeneity observed among head and neck subsites may go beyond HPV infection. In this review, we explore how alterations of DNA methylation and microRNA expression contribute to head and neck squamous cell carcinoma (HNSCC) development and progression. The association of these epigenetic alterations with risk factor exposure, early carcinogenesis steps, transformation risk, and prognosis are described. Finally, we discuss the potential application of the use of epigenetic biomarkers in HNSCC.

Abstract

Head and neck squamous cell carcinomas (HNSCC) are among the ten most frequent types of cancer worldwide and, despite all efforts, are still diagnosed at late stages and show poor overall survival. Furthermore, HNSCC patients often experience relapses and the development of second primary tumors, as a consequence of the field cancerization process. Therefore, a better comprehension of the molecular mechanisms involved in HNSCC development and progression may enable diagnosis anticipation and provide valuable tools for prediction of prognosis and response to therapy. However, the different biological behavior of these tumors depending on the affected anatomical site and risk factor exposure, as well as the high genetic heterogeneity observed in HNSCC are major obstacles in this pursue. In this context, epigenetic alterations have been shown to be common in HNSCC, to discriminate the tumor anatomical subsites, to be responsive to risk factor exposure, and show promising results in biomarker development. Based on this, this review brings together the current knowledge on alterations of DNA methylation and microRNA expression in HNSCC natural history, focusing on how they contribute to each step of the process and on their applicability as biomarkers of exposure, HNSCC development, progression, and response to therapy.

miR-30a attenuates drug sensitivity to 5-FU by modulating cell proliferation possibly by downregulating cyclin E2 in oral squamous cell carcinoma

We aimed to determine the functional role of the miRNA, which affects drug sensitivity to 5-FU in oral squamous cell carcinoma (OSCC), using two types of 5-FU-resistant and parental OSCC cell lines. MiRNA microarray data showed that miR-30a was significantly upregulated in two resistant cell lines. Therefore, we investigated the effects and molecular mechanism of miR-30a on 5-FU sensitivity. Stable overexpression of miR-30a in parental OSCC cells decreased cell proliferation and attenuated drug sensitivity to 5-FU. Cell cycle analysis indicated that miR-30a overexpression increased the proportion of G1 phase cells and decreased the proportion of S phase cells. MiR-30a knockdown using siRNA reversed the effects of miR-30a overexpression. DNA microarray analysis using miR-30a-overexpressing cell lines and a TargetScan database search showed that cyclin E2 (CCNE2) is a target of miR-30a. A luciferase reporter assay confirmed that a miR-30a mimic interacted with the specific binding site in the 3' UTR of CCNE2. CCNE2 knockdown with siRNA in OSCC cells yielded decreased drug sensitivity to 5-FU, similar to miR-30a overexpressing cells. These findings suggest that miR-30a in OSCC may be a novel biomarker of 5-FU-resistant tumors, as well as a therapeutic target for combating resistance.

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miR-30a overexpression increased the proportion of G1 phase cells.

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miR-30a knockdown using si-RNA reversed the effects of miR-30a overexpression.

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CCNE2 knockdown with si-RNA in OSCC cells decreased drug sensitivity to 5-FU.

The role of non-coding RNAs in drug resistance of oral squamous cell carcinoma and therapeutic potential

Oral squamous cell carcinoma (OSCC), the eighth most prevalent cancer in the world, arises from the interaction of multiple factors including tobacco, alcohol consumption, and betel quid. Chemotherapeutic agents such as cisplatin, 5-fluorouracil, and paclitaxel have now become the first-line options for OSCC patients. Nevertheless, most OSCC patients eventually acquire drug resistance, leading to poor prognosis. With the discovery and identification of non-coding RNAs (ncRNAs), the functions of dysregulated ncRNAs in OSCC development and drug resistance are gradually being widely recognized. The mechanisms of drug resistance of OSCC are intricate and involve drug efflux, epithelial-mesenchymal transition, DNA damage repair, and autophagy. At present, strategies to explore the reversal of drug resistance of OSCC need to be urgently developed. Nano-delivery and self-cellular drug delivery platforms are considered as effective strategies to overcome drug resistance due to their tumor targeting, controlled release, and consistent pharmacokinetic profiles. In particular, the combined application of new technologies (including CRISPR systems) opened up new horizons for the treatment of drug resistance of OSCC. Hence, this review explored emerging regulatory functions of ncRNAs in drug resistance of OSCC, elucidated multiple ncRNA-meditated mechanisms of drug resistance of OSCC, and discussed the potential value of drug delivery platforms using nanoparticles and self-cells as carriers in drug resistance of OSCC.

Let-7a-5p, miR-100-5p, miR-101-3p, and miR-199a-3p Hyperexpression as Potential Predictive Biomarkers in Early Breast Cancer Patients

BACKGROUND

The aim of this study is to identify miRNAs able to predict the outcomes in breast cancer patients after neoadjuvant chemotherapy (NAC).

PATIENTS AND METHODS

We retrospectively analyzed 24 patients receiving NAC and not reaching pathologic complete response (pCR). miRNAs were analyzed using an Illumina Next-Generation-Sequencing (NGS) system.

RESULTS

Event-free survival (EFS) and overall survival (OS) were significantly higher in patients with up-regulation of let-7a-5p (EFS p = 0.006; OS p = 0.0001), mirR-100-5p (EFS s p = 0.01; OS p = 0.03), miR-101-3p (EFS p = 0.05; OS p = 0.01), and miR-199a-3p (EFS p = 0.02; OS p = 0.01) in post-NAC samples, independently from breast cancer subtypes. At multivariate analysis, only let-7a-5p was significantly associated with EFS (p = 0.009) and OS (p = 0.0008).

CONCLUSION

Up-regulation of the above miRNAs could represent biomarkers in breast cancer.

Molecular mechanism involved in epithelial to mesenchymal transition

Epithelial to mesenchymal transition (EMT) is a biological process that plays an important role during embryonic development. During this process, the epithelial cells lose their polarity and acquire mesenchymal properties. In addition to embryonic development, EMT is also well-known to participate in tissue repair, inflammation, fibrosis, and tumor metastasis. In the present review, we address the basics of epithelial to mesenchymal transition during both development and disease conditions and emphasize the role of various transcription factors and miRNAs involved in the process.

Emerging Role of MicroRNA-200 Family in Dentistry

MicroRNAs (miRNAs) are endogenous non-coding RNAs ~22 nucleotides in length, which have been shown to participate in various biological processes. As one of the most researched miRNAs, the miR-200 family has been found to regulate several factors that are associated with the epithelial to mesenchymal transition (EMT) and cancer stem cells (CSCs) behavior. In this review, we briefly summarize the background of the miR-200 family and their implication in various dental diseases. We focus on the expression changes, biological functions, and clinical significance of the miR-200 family in oral cancer; periodontitis; oral potentially malignant disorder; gingival overgrowth; and other periodontal diseases. Additionally, we discuss the use of the miR-200 family as molecular biomarkers for diagnosis, prognostic, and therapeutic application.

Tongue Cancer Cell-Derived CCL20 Induced by Interaction With Macrophages Promotes CD163 Expression on Macrophages

Background

CD163-positive macrophages contribute to the aggressiveness of oral squamous cell carcinoma. We showed in a previous report that CD163-positive macrophages infiltrated not only to the cancer nest but also to its surrounding epithelium, depending on the presence of stromal invasion in tongue carcinogenesis. However, the role of intraepithelial macrophages in tongue carcinogenesis remains unclear. In this study, we assessed the biological behavior of intraepithelial macrophages on their interaction with cancer cells.

Materials and Methods

We established the indirect coculture system (intraepithelial neoplasia model) and direct coculture system (invasive cancer model) of human monocytic leukemia cell line THP-1-derived CD163-positive macrophages with SCC25, a tongue squamous cell carcinoma (TSCC) cell line. Conditioned media (CM) harvested from these systems were analyzed using cytokine array and enzyme-linked immunosorbent assay and extracted a specific upregulated cytokine in CM from the direct coculture system (direct CM). The correlation of both this cytokine and its receptor with various clinicopathological factors were evaluated based on immunohistochemistry using clinical samples from 59 patients with TSCC. Moreover, the effect of this cytokine in direct CM on the phenotypic alterations of THP-1 was confirmed by real-time polymerase chain reaction, western blotting, immunofluorescence, and transwell migration assay.

Results

It was shown that CCL20 was induced in the direct CM specifically. Interestingly, CCL20 was produced primarily in SCC25. The expression level of CCR6, which is a sole receptor of CCL20, was higher than the expression level of SCC25. Our immunohistochemical investigation showed that CCL20 and CCR6 expression was associated with lymphatic vessel invasion and the number of CD163-positive macrophages. Recombinant human CCL20 induced the CD163 expression and promoted migration of THP-1. We also confirmed that a neutralizing anti-CCL20 antibody blocked the induction of CD163 expression by direct CM in THP-1. Moreover, ERK1/2 phosphorylation was associated with the CCL20-driven induction of CD163 expression in THP-1.

Conclusions

Tongue cancer cell-derived CCL20 that was induced by interaction with macrophages promotes CD163 expression on macrophages.

LUCAT1 as an oncogene in tongue squamous cell carcinoma by targeting miR-375 expression

Emerging studies suggested that lncRNAs play a crucial molecular role in cancer development and progression. LncRNA LUCAT1 has been proved as oncogenic molecular in lung cancer, glioma, osteosarcoma, renal carcinoma and oesophageal squamous cell carcinoma. However, its roles and function mechanisms in tongue squamous cell carcinoma (TSCC) are still unknown. We showed that the expression of LUCAT1 was up‐regulated in the TSCC cells and tissues and the higher LUCAT1 expression was associated with the poor overall survival (OS). Knockdown expression of LUCAT1 suppressed TSCC cell proliferation, cycle and migration. In addition, we demonstrated that miR‐375 overexpression inhibited the luciferase activity of LUCAT1 wild‐type and knockdown LUCAT1 promoted the miR‐375 expression in TSCC cell. Furthermore, we indicated that miR‐375 expression was down‐regulated in the TSCC cell lines and tissues and the lower expression of miR‐375 was associated with poor OS. The expression of miR‐375 was inversely correlated with LUCAT1 expression in the TSCC tissues. Knockdown LUCAT1 promoted TSCC cell proliferation, cell cycle and migration partly through regulating miR‐375 expression. In summary, this study suggested the tumorigenic effect of lncRNA LUCAT1 in TSCC cells by targeting miR‐375 expression.

lncRNA RPSAP52 induced the development of tongue squamous cell carcinomas via miR-423-5p/MYBL2

Growing lncRNAs have been noted to involve in the initiation and development of several tumours including tongue squamous cell carcinomas (TSCCs). However, the biological role and mechanism of lncRNA RPSAP52 were not well‐explained. We indicated that RPSAP52 was higher in TSCC samples compared with that in control samples. The higher expression of RPSAP52 was positively correlated with higher T stage and TNM stage. Ectopic expression of RPSAP52 induced TSCC cell growth and cycle and induced cytokine secretion including IFN‐γ, IL‐1β and IL‐6, IL‐8, IL‐10 and TGF‐β. We found that the overexpression of RPSAP52 suppressed miR‐423‐5p expression in SCC‐4 cell. miR‐423‐5p was lower in TSCC samples compared with that in control samples, and miR‐423‐5p level was negatively correlated with higher T stage and TNM stage. Pearson's correlation indicated that miR‐423‐5p was negatively associated with that of RPSAP52 in TSCC tissues. Furthermore, MYBL2 was one direct gene of miR‐423‐5p and elevated expression of miR‐423‐5p suppressed MYBL2 expression and ectopic expression of RPSAP52 increased MYBL2 expression in SCC‐4 cell. Finally, we illustrated that RPSAP52 overexpression promoted TSCC cell growth and cycle and induced cytokine secretion including IFN‐γ, IL‐1β and IL‐6, IL‐8, IL‐10 and TGF‐β via modulating MYBL2. These data provided new insight into RPSAP52, which may be one potential treatment target for TSCC.

Bioinformatics analysis of dysregulated exosomal microRNAs derived from oral squamous cell carcinoma cells

PURPOSE

The present study aimed to identify dysregulated exosomal miRNAs associated with diagnostic and therapeutic biomarkers in oral squamous cell carcinoma (OSCC).

METHODS

Microarray analysis was used to compare expression profiles of exosomal miRNAs in the OSCC-derived cell lines HSC-2, HSC-3, Ca9-22, and HO-1-N1 with those in human normal keratinocytes (HNOKs). The identified OSCC-related miRNAs and their potential target genes were analyzed with bioinformatic analyses, and the data were subjected to Ingenuity Pathway Analysis (IPA) to clarify functional networks and gene ontologies of the identified exosomal miRNAs secreted by OSCC cells.

RESULTS

Comparison with HNOKs detected 8 upregulated and 12 downregulated miRNAs in OSCC-secreted exosomes. The potential target mRNAs of these dysregulated miRNAs were suggested by IPA, and 6 significant genetic networks were indicated by genetic network analysis. Furthermore, 4 crucial upstream miRNAs-miR-125b-5p, miR-17-5p, miR-200b-3p, and miR-23a-3p-were identified. miR-125b-5p was a central node in the most significant network. Gene ontology analysis showed significant enrichment of genes with cancer-related functions, such as molecular mechanisms of cancer, cell cycle, and regulation of the epithelial-mesenchymal transition.

CONCLUSION

These results provide a comprehensive view of the functions of dysregulated exosomal miRNAs in OSCC, thus illuminating OSCC tumorigenesis and development.

MicroRNAs in oral cancer: Biomarkers with clinical potential

Oral cancer is the sixteenth most common cancer globally, with a relatively poor five-year survival rate of 50%. Thus it is imperative to understand the biology of oral cancer and examine alternative prognostic and therapeutic targets for oral cancer. MicroRNAs (miRNAs) are small non-coding RNAs mediating gene expression at the post-transcriptional level through mRNA degradation or translational repression. miRNAs play an essential role in cancer development and oncogenic cell processes. miRNA deregulation is observed in oral cancer and associated with prognosis. However, the role of miRNAs and their clinical implications in oral cancer is not clear. The current review highlights the miRNA profile of oral cancer and discusses the diagnostic, prognostic and potential therapeutic targets with clinical implications. miRNAs mediate activation or suppression of signalling pathways associated with oral cancer. Hence, a panel of select deregulated miRNAs may indicate clinicopathological features, personalised treatment outcome and provide novel lead profiles of oral cancer. The translational applications of miRNAs may lead to better management and survival of oral cancer patients. The compiled data provides a platform for consideration of miRNA signatures as potential biomarkers for early oral cancer diagnosis, prognosis and as novel molecular therapies.

Y-box binding protein 1 (YB-1) promotes gefitinib resistance in lung adenocarcinoma cells by activating AKT signaling and epithelial-mesenchymal transition through targeting major vault protein (MVP)

PURPOSE

Gefitinib is a first-line treatment option for epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma. However, most patients inevitably develop gefitinib resistance. The mechanism underlying this resistance is not fully understood. Y-box binding protein 1 (YB-1) has been reported to play a role in modulating drug sensitivity, but its role in gefitinib resistance is currently unknown. Here, we investigated the role of YB-1 in gefitinib resistance of lung adenocarcinoma.

METHODS

We determined the expression of YB-1, epithelial-mesenchymal transition (EMT) and AKT signaling markers, as well as the viability of lung adenocarcinoma cell lines bearing mutant (HCC827, PC-9) or wild-type (H1299) EGFR. We also evaluated PC-9 cell migration and invasion using transwell assays. The clinical importance of YB-1 and major vault protein (MVP) was evaluated using primary lung adenocarcinoma patient samples.

RESULTS

We found that YB-1 was significantly upregulated in gefitinib-resistant lung adenocarcinoma cells compared to gefitinib-sensitive cells. YB-1 augmented gefitinib resistance by activating the AKT pathway and promoting EMT. Decreased migration and invasion was observed upon MVP silencing in YB-1-overexpressing PC-9 cells, as well as restored gefitinib sensitivity. A retrospective analysis of 85 patients with lung adenocarcinoma revealed that YB-1 levels were significantly increased in tyrosine kinase inhibitor (TKI)-resistant patients compared to those in TKI-sensitive patients, indicating that YB-1 may serve as a biomarker to clinically predict acquired gefitinib resistance.

CONCLUSION

YB-1 activates AKT signaling and promotes EMT at least in part by directly activating MVP. Hence, targeting the YB-1/MVP axis may help to overcome gefitinib resistance in lung adenocarcinoma patients.

The roles of microRNAs in the stemness of oral cancer cells

Oral cancer (OC), which is the most common form of head and neck cancers, has one of the lowest (~50%) overall 5-year survival rates. The main reasons for this high mortality rate are diagnosis of OC in advanced stages in most patients and spread to distant organs via lymph node metastasis. Many studies have shown that a small population of cells within the tumor plays vital roles in the initiation, progression, and metastasis of the tumor, resistance to chemotherapeutic agents, and recurrence. These cells, identified as cancer stem cells (CSCs), are the main reasons for the failure of current treatment modalities. Deregulated expressions of microRNAs are closely related to tumor prognosis, metastasis and drug resistance. In addition, microRNAs play important roles in regulating the functions of CSCs. Until now, the roles of microRNAs in the acquisition and maintenance of OC stemness have not been elucidated in detail yet. Here in this review, we summarized significant findings and the latest literature to better understand the involvement of CSCs in association with dysregulated microRNAs in oral carcinogenesis. Possible roles of these microRNAs in acquisition and maintenance of CSCs features during OC pathogenesis were summarized.

microRNAs in oral cancer: Moving from bench to bed as next generation medicine

Oral cancer is the thirteenth most common cancer in the world, with India contributing to 33% of the global burden. Lack of specific non-invasive markers, non-improvement in patient survival and tumor recurrence remain a major clinical challenge in oral cancer. Epigenetic regulation in the form of microRNAs (miRs) that act as tumor suppressor miRs or oncomiRs has gained significant momentum with the advancement in the field, suggesting the potential for clinical application of miRs in oral cancer. The current review of literature identified miR-21, miR-27a(-3p), miR-31, miR-93, miR-134, miR-146, miR-155, miR-196a, miR-196b, miR-211, miR-218, miR-222, miR-372 and miR-373 to be up-regulated and let-7a, let-7b, let-7c, let-7d, let-7e, let-7f, let-7g, let-7i, miR-26a, miR-99a-5p, miR-137, miR-139-5p, miR-143-3p, miR-184 and miR-375 to be down-regulated in oral cancer. Mechanistic studies have uncovered several miRs that are deregulated at varying levels and in different stages of oral cancer progression, thus providing clinical utility in better diagnosis as well as usefulness in prognosis by identifying patients with poor prognosis or stratifying patients based on responsiveness to chemo- and radio-therapy. Lastly, exogenous modulation of miR expression using miRNA-based drugs in combination with first-line agents may be adopted as a new therapeutic modality to treat oral cancer. Knowledge of miRs and their involvement in key molecular processes, clinical association, responsiveness to therapy and clinical advancement may highlight additional avenues in order to improve patient morbidity and mortality. Furthermore, combinatorial approaches with miR-therapy may be efficacious in oral cancer.

The Role of miR-200b-3p in Modulating TGF-β1-induced Injury in Human Bronchial Epithelial Cells

BACKGROUND

Dysregulation of microRNAs (miRNAs) has been implicated in airway diseases where transforming growth factor-β (TGF-β)-induced epithelial-mesenchymal transition (EMT) may contribute to pathophysiology. Our study investigated the role of miRNA-200b in TGF-β1-induced EMT in human bronchial epithelial cells.

METHODS

NanoString nCounter miRNA assay was used to profile miRNA in control versus TGF-β1 (1, 4, and 24 h) stimulated BEAS-2B cells. Immortalized primary bronchial epithelial cell line (BEAS-2B cells), human primary bronchial epithelial cells (PBECs), and PBECs derived post-lung transplant were transfected with miR-200b-3p mimics and EMT marker expression was examined at RNA and protein level. miRNA target studies were performed and validated using computational tools and luciferase assay. In situ hybridization was done on normal lung tissue to localize miR-200b-3p in airway epithelium.

RESULTS

miR-200b-3p was downregulated post-TGF-β1 treatment compared with control in BEAS-2B. miR-200b-3p mimic transfection before TGF-β1 stimulation maintained epithelial marker expression and downregulated mesenchymal cell markers at RNA and protein level in BEAS-2B cells and PBECs. Furthermore, miR-200b-3p mimics reversed established TGF-β1-induced EMT in BEAS-2B cells. miR-200b-3p targets, ZNF532, and ZEB2 were validated as direct targets using luciferase assay. miR-200b-3p mimics suppress TGF-β1-induced EMT via inhibition of ZNF532 and ZEB2. In situ hybridization showed that miR-200b-3p is expressed in the normal lung epithelium. Additionally, miR-200b-3p mimics inhibit EMT in the presence of TGF-β1 in PBECs derived from lung allograft.

CONCLUSIONS

We provide proof of concept that miR-200b-3p protects airway epithelial cells from EMT. Manipulating miR-200b-3p expression may represent a novel therapeutic modulator in airway pathophysiology.

Metabolic Escape Routes of Cancer Stem Cells and Therapeutic Opportunities

Although improvement in early diagnosis and treatment ameliorated life expectancy of cancer patients, metastatic disease still lacks effective therapeutic approaches. Resistance to anticancer therapies stems from the refractoriness of a subpopulation of cancer cells-termed cancer stem cells (CSCs)-which is endowed with tumor initiation and metastasis formation potential. CSCs are heterogeneous and diverge by phenotypic, functional and metabolic perspectives. Intrinsic as well as extrinsic stimuli dictated by the tumor microenvironment (TME)have critical roles in determining cell metabolic reprogramming from glycolytic toward an oxidative phenotype and vice versa, allowing cancer cells to thrive in adverse milieus. Crosstalk between cancer cells and the surrounding microenvironment occurs through the interchange of metabolites, miRNAs and exosomes that drive cancer cells metabolic adaptation. Herein, we identify the metabolic nodes of CSCs and discuss the latest advances in targeting metabolic demands of both CSCs and stromal cells with the scope of improving current therapies and preventing cancer progression.

Non-coding RNAs in drug resistance of head and neck cancers: A review

Head and neck cancer (HNC), which includes epithelial malignancies of the upper aerodigestive tract (oral cavity, oropharynx, pharynx, hypopharynx, larynx, and thyroid), are slowly but consistently increasing, while the overall survival rate remains unsatisfactory. Because of the multifunctional anatomical intricacies of the head and neck, disease progression and therapy-related side effects often severely affect the patient's appearance and self-image, as well as their ability to breathe, speak, and swallow. Patients with HNC require a multidisciplinary approach involving surgery, radiation therapy, and chemotherapeutics. Chemotherapy is an important part of the comprehensive treatment of tumors, especially advanced HNC, but drug resistance is the main cause of poor clinical efficacy. The most important determinant of this phenomenon is still largely unknown. Recent studies have shown that non-coding RNAs have a crucial role in HNC drug resistance. In addition, they can serve as biomarkers in the diagnosis, treatment, and prognosis of HNCs. In this review, we summarize the relationship between non-coding RNAs and drug resistance of HNC, and discuss their potential clinical application in overcoming HNC chemoresistance.

Functional Landscape of Dysregulated MicroRNAs in Oral Squamous Cell Carcinoma: Clinical Implications

MicroRNA (miRNA) dysregulation is associated with the pathogenesis of oral squamous cell carcinoma (OSCC), and its elucidation could potentially provide information on patient outcome. A growing body of translational research on miRNA biology is focusing on precision oncology, aiming to decode the miRNA regulatory network in the development and progression of cancer. Tissue-specific expression and stable presence in all body fluids are unique features of miRNAs, which could be potentially exploited in the clinical setting. Recent understanding of miRNA properties has led them to be useful, attractive, and potential tools either as biomarkers (distinct miRNA expression signature) for diagnosis and prognostic outcomes or as targets for novel therapeutic entities, enabling personalized treatment for OSCC. In this review, we discuss recent research on different aspects of alterations in miRNA profiles along with their clinical significance and strive to identify probable potential miRNA biomarkers for diagnosis and prognosis of OSCC. We also discuss the current understanding and scope of development of miRNA-based therapeutics against OSCC.

TUG1/miR-133b/CXCR4 axis regulates cisplatin resistance in human tongue squamous cell carcinoma

Background

Long noncoding RNA taurine upregulated 1 (TUG1) has been reported to play an important role in human cancers. However, little is known about the role of TUG1 in drug resistance and its mechanism in tongue squamous cell carcinoma (TSCC).

Methods

Twenty-one cisplatin-sensitive or resistant TSCC patients were enrolled in this study. Cisplatin-resistant cells (SCC25/CDDP and CAL27/CDDP) were used for experiments in vitro. Transfection was performed using Lipofectamine 2000 transfection reagent. The levels of TUG1, microRNA-133b (miR-133b) and cysteine-X-cysteine chemokine receptor 4 (CXCR4) were measured by quantitative real-time polymerase chain reaction or western blot. The cisplatin resistance was investigated by cell viability, transwell invasion and apoptosis assays. The interactions among TUG1, miR-133b and CXCR4 were evaluated by luciferase reporter assay and RNA immunoprecipitation. Murine xenograft model was established using the stably transfected CAL27/CDDP cells.

Results

TUG1 expression was elevated in cisplatin-resistant TSCC tissues and cells compared with that in sensitive group and its knockdown inhibited cisplatin resistance to SCC25/CDDP and CAL27/CDDP cells. miR-133b was targeted via TUG1 and its overexpression suppressed cisplatin resistance. Moreover, CXCR4 was a target of miR-133b. CXCR4 silence repressed cisplatin resistance, which was reversed by miR-133b knockdown. The level of CXCR4 protein was decreased by inhibition of TUG1 and recuperated by miR-133b knockdown. Besides, interference of TUG1 attenuated tumor growth by regulating miR-133b and CXCR4 in vivo.

Conclusion

Downregulation of TUG1 impeded cisplatin resistance in TSCC-resistant cells by mediating miR-133b and CXCR4, indicating TUG1 as a promising target for TSCC chemotherapy.

Transcompp: understanding phenotypic plasticity by estimating Markov transition rates for cell state transitions

MOTIVATION

Gradual population-level changes in tissues can be driven by stochastic plasticity, meaning rare stochastic transitions of single-cell phenotype. Quantifying the rates of these stochastic transitions requires time-intensive experiments, and analysis is generally confounded by simultaneous bidirectional transitions and asymmetric proliferation kinetics. To quantify cellular plasticity, we developed Transcompp (Transition Rate ANalysis of Single Cells to Observe and Measure Phenotypic Plasticity), a Markov modeling algorithm that uses optimization and resampling to compute best-fit rates and statistical intervals for stochastic cell-state transitions.

RESULTS

We applied Transcompp to time-series datasets in which purified subpopulations of stem-like or non-stem cancer cells were exposed to various cell culture environments, and allowed to re-equilibrate spontaneously over time. Results revealed that commonly used cell culture reagents hydrocortisone and cholera toxin shifted the cell population equilibrium toward stem-like or non-stem states, respectively, in the basal-like breast cancer cell line MCF10CA1a. In addition, applying Transcompp to patient-derived cells showed that transition rates computed from short-term experiments could predict long-term trajectories and equilibrium convergence of the cultured cell population.

AVAILABILITY AND IMPLEMENTATION

Freely available for download at http://github.com/nsuhasj/Transcompp.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Suppression of migration, invasion, and metastasis of cisplatin-resistant head and neck squamous cell carcinoma through IKKβ inhibition

We explored the role of the transcription factor, NF-κB, and its upstream kinase IKKβ in regulation of migration, invasion, and metastasis of cisplatin-resistant head and neck squamous cell carcinoma (HNSCC). We showed that cisplatin-resistant HNSCC cells have a stronger ability to migrate and invade, as well as display higher IKKβ/NF-κB activity compared to their parental partners. Importantly, we found that knockdown of IKKβ, but not NF-κB, dramatically impaired cell migration and invasion in these cells. Consistent with this, the IKKβ inhibitor, CmpdA, also inhibited cell migration and invasion. Previous studies have already shown that N-Cadherin, an epithelial-mesenchymal transition (EMT) marker, and IL-6, a pro-inflammatory cytokine, play important roles in regulation of HNSCC migration, invasion, and metastasis. We found that cisplatin-resistant HNSCC expressed higher levels of N-Cadherin and IL-6, which were significantly inhibited by CmpdA. More importantly, we showed that CmpdA treatment dramatically abated cisplatin-resistant HNSCC cell metastasis to lungs in a mouse model. Our data demonstrated the crucial role of IKKβ in control of migration, invasion, and metastasis, and implicated that targeting IKKβ may be a potential therapy for cisplatin-resistant metastatic HNSCC.

Upregulation of CD73 Confers Acquired Radioresistance and is Required for Maintaining Irradiation-selected Pancreatic Cancer Cells in a Mesenchymal State

The molecular mechanisms underlying exceptional radioresistance in pancreatic cancer remain elusive. In the present study, we established a stable radioresistant pancreatic cancer cell line MIA PaCa-2-R by exposing the parental MIA PaCa-2 cells to fractionated ionizing radiation (IR). Systematic proteomics and bioinformatics analysis of protein expression in MIA PaCa-2 and MIA PaCa-2-R cells revealed that several growth factor-/cytokine-mediated pathways, including the OSM/STAT3, PI3K/AKT, and MAPK/ERK pathways, were activated in the radioresistant cells, leading to inhibition of apoptosis and increased epithelial-mesenchymal plasticity. In addition, the radioresistant cells exhibited enhanced capabilities of DNA repair and antioxidant defense compared with the parental cells. We focused functional analysis on one of the most up-regulated proteins in the radioresistant cells, ecto-5'-nucleotidase (CD73), which is a cell surface protein that is overexpressed in different types of cancer. Ectopic overexpression of CD73 in the parental cells resulted in radioresistance and conferred resistance to IR-induced apoptosis. Knockdown of CD73 re-sensitized the radioresistant cells to IR and IR-induced apoptosis. The effect of CD73 on radioresistance and apoptosis is independent of the enzymatic activity of CD73. Further studies demonstrate that CD73 up-regulation promotes Ser-136 phosphorylation of the proapoptotic protein BAD and is required for maintaining the radioresistant cells in a mesenchymal state. Our findings suggest that expression alterations in the IR-selected pancreatic cancer cells result in hyperactivation of the growth factor/cytokine signaling that promotes epithelial-mesenchymal plasticity and enhancement of DNA repair. Our results also suggest that CD73, potentially a novel downstream factor of the enhanced growth factor/cytokine signaling, confers acquired radioresistance by inactivating proapoptotic protein BAD via phosphorylation of BAD at Ser-136 and by maintaining the radioresistant pancreatic cancer cells in a mesenchymal state.

Endogenous and artificial miRNAs explore a rich variety of conformations: a potential relationship between secondary structure and biological functionality

Mature microRNAs are short non-coding RNA sequences which upon incorporation into the RISC ribonucleoprotein complex, play a crucial role in regulation of gene expression. However, miRNAs can exist within the cell also as free molecules fulfilling their biological activity. Therefore, it is emerging that in addition to sequence even the structure adopted by mature miRNAs might play an important role to reach the target. Indeed, we analysed by several spectroscopic techniques the secondary structures of two artificial miRNAs selected by computational tool (miR-Synth) as best candidates to silence c-MET and EGFR genes and of two endogenous miRNAs (miR-15a and miR-15b) having the same seed region, but different biological activity. Our results demonstrate that both endogenous and artificial miRNAs can arrange in several 3D-structures which affect their activity and selectivity toward the targets.

Chemical compound cinobufotalin potently induces FOXO1-stimulated cisplatin sensitivity by antagonizing its binding partner MYH9

In this study, we present novel molecular mechanisms by which FOXO1 functions as a tumor suppressor to prevent the pathogenesis of nasopharyngeal carcinoma (NPC). First, we observed that FOXO1 not only controlled tumor stemness and metastasis, but also sensitized NPC cells to cisplatin (DDP) in vitro and in vivo. Mechanistic studies demonstrated that FOXO1-induced miR-200b expression through the GSK3β/β-catenin/TCF4 network-mediated stimulation of ZEB1, which reduced tumor stemness and the epithelial-mesenchymal transition (EMT) signal. Furthermore, we observed FOXO1 interaction with MYH9 and suppression of MYH9 expression by modulating the PI3K/AKT/c-Myc/P53/miR-133a-3p pathway. Decreased MYH9 expression not only reduced its interactions with GSK3β, but also attenuated TRAF6 expression, which then decreased the ubiquitin-mediated degradation of GSK3β protein. Increased GSK3β expression stimulated the β-catenin/TCF4/ZEB1/miR-200b network, which increased the downstream tumor stemness and EMT signals. Subsequently, we observed that chemically synthesized cinobufotalin (CB) strongly increased FOXO1-induced DDP chemosensitivity by reducing MYH9 expression, and the reduction in MYH9 modulated GSK3β/β-catenin and its downstream tumor stemness and EMT signal in NPC. In clinical samples, the combination of low FOXO1 expression and high MYH9 expression indicated the worst overall survival rates. Our studies demonstrated that CB potently induced FOXO1-mediated DDP sensitivity by antagonizing its binding partner MYH9 to modulate tumor stemness in NPC.

A novel BMI-1 inhibitor QW24 for the treatment of stem-like colorectal cancer

Background

Cancer-initiating cell (CIC), a functionally homogeneous stem-like cell population, is resonsible for driving the tumor maintenance and metastasis, and is a source of chemotherapy and radiation-therapy resistance within tumors. Targeting CICs self-renewal has been proposed as a therapeutic goal and an effective approach to control tumor growth. BMI-1, a critical regulator of self-renewal in the maintenance of CICs, is identified as a potential target for colorectal cancer therapy.

Methods

Colorectal cancer stem-like cell lines HCT116 and HT29 were used for screening more than 500 synthetic compounds by sulforhodamine B (SRB) cell proliferation assay. The candidate compound was studied in vitro by SRB cell proliferation assay, western blotting, cell colony formation assay, quantitative real-time PCR, flow cytometry analysis, and transwell migration assay. Sphere formation assay and limiting dilution analysis (LDA) were performed for measuring the effect of compound on stemness properties. In vivo subcutaneous tumor growth xenograft model and liver metastasis model were performed to test the efficacy of the compound treatment. Student’s t test was applied for statistical analysis.

Results

We report the development and characterization of a small molecule inhibitor QW24 against BMI-1. QW24 potently down-regulates BMI-1 protein level through autophagy-lysosome degradation pathway without affecting the BMI-1 mRNA level. Moreover, QW24 significantly inhibits the self-renewal of colorectal CICs in stem-like colorectal cancer cell lines, resulting in the abrogation of their proliferation and metastasis. Notably, QW24 significantly suppresses the colorectal tumor growth without obvious toxicity in the subcutaneous xenograft model, as well as decreases the tumor metastasis and increases mice survival in the liver metastasis model. Moreover, QW24 exerts a better efficiency than the previously reported BMI-1 inhibitor PTC-209.

Conclusions

Our preclinical data show that QW24 exerts potent anti-tumor activity by down-regulating BMI-1 and abrogating colorectal CICs self-renewal without obvious toxicity in vivo, suggesting that QW24 could potentially be used as an effective therapeutic agent for clinical colorectal cancer treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1392-8) contains supplementary material, which is available to authorized users.

MicroRNAs as Therapeutic Targets in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is a malignancy of epithelial origin that is prone to local invasion and early distant metastasis. Although concurrent chemotherapy and radiotherapy improves the 5-year survival outcomes, persistent or recurrent disease still occurs. Therefore, novel therapeutic targets are needed for NPC patients. MicroRNAs (miRNAs) play important roles in normal cell homeostasis, and dysregulations of miRNA expression have been implicated in human cancers. In NPC, studies have revealed that miRNAs are dysregulated and involved in tumorigenesis, metastasis, invasion, resistance to chemo- and radiotherapy, and other disease- and treatment-related processes. The advantage of miRNA-based treatment approaches is that miRNAs can concurrently target multiple effectors of pathways involved in tumor cell differentiation and proliferation. Thus, miRNA-based cancer treatments, alone or combined with standard chemotherapy and/or radiotherapy, hold promise to improve treatment response and cure rates. In this review, we will summarize the dysregulation of miRNAs in NPC initiation, progression, and treatment as well as NPC-related signaling pathways, and we will discuss the potential applications of miRNAs as biomarkers and therapeutic targets in NPC patients. We conclude that miRNAs might be potential promising therapeutic targets in nasopharyngeal carcinoma.

Decreased expression of mitochondrial miR-5787 contributes to chemoresistance by reprogramming glucose metabolism and inhibiting MT-CO3 translation

MicroRNAs (miRNAs) have been recently found in the mitochondria, and were named “mitomiRs”, but their function has remained elusive. Here, we aimed to assess the presence and function(s) of mitomiRs in tongue squamous cell carcinoma (TSCC).

Methods: miRNA microarray was performed in paired TSCC cell lines, Cal27 and its chemoresistant counterpart, Cal27-re. Decreased expression of mitomiRs in chemoresistant cells was characterized. The functions of mitomiRs were investigated by a series of in vitro and in vivo experiments.

Results: Differential microarray analysis identified downregulation of mitomiR-5787 in Cal27-re cells. We knocked down mitomiR-5787 in parental cells and upregulated its expression in cisplatin-resistant cells. The sensitivity of TSCC cells to cisplatin was regulated by miR-5787. The glucose metabolism assay suggested that reduced expression of miR-5787 changed the balance of glucose metabolism by shifting it from oxidative phosphorylation to aerobic glycolysis. Xenograft experiments in BALB/c-nu mice further verified the in vitro results. Reduced expression of miR-5787 contributes to chemoresistance in TSCC cells by inhibiting the translation of mitochondrial cytochrome c oxidase subunit 3 (MT-CO3). The prognostic analysis of 126 TSCC patients showed that the patients with low expression of miR-5787 and/or MT-CO3 had poor cisplatin sensitivity and prognosis.

Conclusions: Mitochondrial miR-5787 could regulate cisplatin resistance of TSCC cells and affect oxidative phosphorylation and aerobic glycolysis. Downregulation of miR-5787 inhibited the translation of MT-CO3 to regulate cisplatin resistance of TSCC. Mitochondrial miR-5787 and MT-CO3 can be used as predictive biomarkers or therapeutic targets for cisplatin chemotherapy resistance.

miR-671-5p Blocks The Progression Of Human Esophageal Squamous Cell Carcinoma By Suppressing FGFR2

Esophageal cancer is the eighth most common malignant tumor worldwide, of which esophageal squamous cell carcinoma (ESCC) is the dominant histological subtype. A drug shortage for ESCC therapy triggered us to explore the roles of fibroblast growth factor receptor 2 (FGFR2) and its upstream regulator miR-671-5p in ESCC progression. We compared the levels of FGFR2 and miR-671-5p between human ESCC tissues and their matched normal esophageal tissues and found an association between higher levels of FGFR2 and lower levels of miR-671-5p in ESCC tissues. High levels of FGFR2 resulted in the activation of the ERK and AKT pathways and a promotion of ESCC progression. High levels of miR-671-5p specifically reduced the expression of FGFR2 and suppressed ESCC progression in both in vitro and in vivo models. Therefore, suppressing FGFR2 and enhancing miR-671-5p expression may be the right approaches for ESCC therapy.

MicroRNA-218 regulates the chemo-sensitivity of cervical cancer cells through targeting survivin

Background: Cervical cancer is one of the most lethal malignancies among women in the world. Every year about 311,365 women die because of cervical cancer. Chemo-resistance is the main reason of the lethal malignancies, and the mechanism of chemo-resistance in cervical cancer still remains largely elusive. Purpose: Previous studies reported that microRNAs played important biological roles in the chemo-resistance in many types of cancers, in the present study we tried to investigate the biological roles of microRNA-218 in chemo-resistance in cervical cancer cells. Results: Real-time PCR results indicated microRNA-218 was downregulated in cisplatin-resistant HeLa/DDP and SiHa/DDP cells compared with the mock HeLa and SiHa cells. CCK-8 assay results showed upregulation of microRNA-218 enhanced the cisplatin sensitivity of cervical cancer cells; while downregulation of microRNA-218 decreased the cisplatin sensitivity of cervical cancer cells. Dual-luciferase assay indicated survivin was a direct target of microRNA-218. Western blotting and PCR results indicated the expression of survivin in HeLa/DDP and SiHa/DDP cells was significantly increased compared with HeLa and SiHa cells. Further study indicated induction of microRNA-218 decreased the expression of survivin while inhibition of microRNA-218 increased the expression of survivin in cervical cancer cells. Cell apoptosis results indicated induction of microRNA-218 induced the cell apoptosis in cervical cancer cells. Conclusion: Our data revealed microRNA-218 enhanced the cisplatin sensitivity in cervical cancer cells through regulation of cell growth and cell apoptosis, which could potentially benefit to the cervical cancer treatment in the future.