Alterations of microRNAs and their targets are associated with acquired resistance of MCF-7 breast cancer cells to cisplatin

Exploring miRNA‑target gene profiles associated with drug resistance in patients with breast cancer receiving neoadjuvant chemotherapy

Exosomal microRNAs (miRNAs) are closely related to drug resistance in patients with breast cancer (BC); however, only a few roles of the exosomal miRNA-target gene networks have been clinically implicated in drug resistance in BC. Therefore, the present study aimed to identify the differential expression of exosomal miRNAs associated with drug resistance and their target mRNAs. In vitro microarray analysis was used to verify differentially expressed miRNAs (DEMs) in drug-resistant BC. Next, tumor-derived exosomes (TDEs) were isolated. Furthermore, it was determined whether the candidate drug-resistant miRNAs were also significant in TDEs, and then putative miRNAs in TDEs were validated in plasma samples from 35 patients with BC (20 patients with BC showing no response and 15 patients with BC showing a complete response). It was confirmed that the combination of five exosomal miRNAs, including miR-125b-5p, miR-146a-5p, miR-484, miR-1246-5p and miR-1260b, was effective for predicting therapeutic response to neoadjuvant chemotherapy, with an area under the curve value of 0.95, sensitivity of 75%, and specificity of 95%. Public datasets were analyzed to identify differentially expressed genes (DEGs) related to drug resistance and it was revealed that BAK1, NOVA1, PTGER4, RTKN2, AGO1, CAP1, and ETS1 were the target genes of exosomal miRNAs. Networks between DEMs and DEGs were highly correlated with mitosis, metabolism, drug transport, and immune responses. Consequently, these targets could be used as predictive markers and therapeutic targets for clinical applications to enhance treatment outcomes for patients with BC.

Restoring microRNA-34a overcomes acquired drug resistance and disease progression in human breast cancer cell lines via suppressing the ABCC1 gene

PURPOSE

Breast cancer is one of the leading types of cancer diagnosed in women. Despite the improvements in chemotherapeutic cure strategies, drug resistance is still an obstacle leading to disease aggressiveness. The small non-coding RNA molecules, miRNAs, have been implicated recently to be involved as regulators of gene expression through the silencing of mRNA targets that contributed to several cellular processes related to cancer metastasis. Hence, the present study aimed to investigate the beneficial role and mechanism of miRNA-34a-based gene therapy as a novel approach for conquering drug resistance mediated by ATP-binding cassette (ABC) transporters in breast cancer cells, besides exploring the associated invasive behaviors.

MATERIAL AND METHODS

Bioinformatics tools were used to predict miRNA ABC transporter targets by tracking the ABC transporter pathway. After the establishment of drug-resistant breast cancer MCF-7 and MDA-MB-231 sublines, cells were transfected with the mimic or inhibitor of miRNA-34a-5p. The quantitative expression of genes involved in drug resistance was performed by QRT-PCR, and the exact ABC transporter target specification interaction was confirmed by dual-luciferase reporter assay. Furthermore, flow cytometric analysis was utilized to determine the ability of miRNA-34a-treated cells against doxorubicin uptake and accumulation in cell cycle phases. The spreading capability was examined by colony formation, migration, and wound healing assays. The apoptotic activity was estimated as well.

RESULTS

Our findings firstly discovered the mechanism of miRNA-34a-5p restoration as an anti-drug-resistant molecule that highly significantly attenuates the expression of ABCC1 via the direct targeting of its 3'- untranslated regions in resistant breast cancer cell lines, with a significant increase of doxorubicin influx by MDA-MB-231/Dox-resistant cells. Additionally, the current data validated a significant reduction of metastatic potentials upon miRNA-34a-5p upregulation in both types of breast cancer-resistant cells.

CONCLUSION

The ectopic expression of miRNA-34a ameliorates the acquired drug resistance and the migration properties that may eventually lead to improved clinical strategies and outcomes for breast cancer patients. Additionally, miRNA-34a could be monitored as a diagnostic/prognostic biomarker for resistant conditions.

Alginate-based hydrogel platform embedding silver nanoparticles and cisplatin: characterization of the synergistic effect on a breast cancer cell line

Introduction: Breast cancer is a significant cause of mortality in women globally, and current treatment approaches face challenges due to side effects and drug resistance. Nanotechnology offers promising solutions by enabling targeted drug delivery and minimizing toxicity to normal tissues. Methods: In this study, we developed a composite platform called (Alg-AgNPs-CisPt), consisting of silver nanoparticles coated with an alginate hydrogel embedding cisplatin. We examined the effectiveness of this nanocomplex in induce synergistic cytotoxic effects on breast cancer cells. Results and Discussion: Characterization using various analytical techniques confirmed the composition of the nanocomplex and the distribution of its components. Cytotoxicity assays and apoptosis analysis demonstrated that the nanocomplex exhibited greater efficacy against breast cancer cells compared to AgNPs or cisplatin as standalone treatments. Moreover, the nanocomplex was found to enhance intracellular reactive oxygen species levels, further validating its efficacy. The synergistic action of the nanocomplex constituents offers potential advantages in reducing side effects associated with higher doses of cisplatin as a standalone treatment. Overall, this study highlights the potential of the (Alg-AgNPs-CisPt) nanocomplex as a promising platform embedding components with synergistic action against breast cancer cells.

In Vitro microRNA Expression Profile Alterations under CDK4/6 Therapy in Breast Cancer

BACKGROUND

Breast cancer is the most common type of cancer worldwide. Cyclin-dependent kinase inhibition is one of the backbones of metastatic breast cancer therapy. However, there are a significant number of therapy failures. This study evaluates the biomarker potential of microRNAs for the prediction of a therapy response under cyclin-dependent kinase inhibition.

METHODS

This study comprises the analysis of intracellular and extracellular microRNA-expression-level alterations of 56 microRNAs under palbociclib mono as well as combination therapy with letrozole. Breast cancer cell lines BT-474, MCF-7 and HS-578T were analyzed using qPCR.

RESULTS

A palbociclib-induced microRNA signature could be detected intracellularly as well as extracellularly. Intracellular miR-10a, miR-15b, miR-21, miR-23a and miR-23c were constantly regulated in all three cell lines, whereas let-7b, let-7d, miR-15a, miR-17, miR-18a, miR-20a, miR-191 and miR301a_3p were regulated only in hormone-receptor-positive cells. Extracellular miR-100, miR-10b and miR-182 were constantly regulated across all cell lines, whereas miR-17 was regulated only in hormone-receptor-positive cells.

CONCLUSIONS

Because they are secreted and significantly upregulated in the microenvironment of tumor cells, miRs-100, -10b and -182 are promising circulating biomarkers that can be used to predict or detect therapy responses under CDK inhibition. MiR-10a, miR-15b, miR-21, miR-23a and miR-23c are potential tissue-based biomarkers.

Transcriptomic analyses of ovarian clear-cell carcinoma with concurrent endometriosis

Introduction

Endometriosis, a benign inflammatory disease whereby endometrial-like tissue grows outside the uterus, is a risk factor for endometriosis-associated ovarian cancers. In particular, ovarian endometriomas, cystic lesions of deeply invasive endometriosis, are considered the precursor lesion for ovarian clear-cell carcinoma (OCCC).

Methods

To explore this transcriptomic landscape, OCCC from women with pathology-proven concurrent endometriosis (n = 4) were compared to benign endometriomas (n = 4) by bulk RNA and small-RNA sequencing.

Results

Analysis of protein-coding genes identified 2449 upregulated and 3131 downregulated protein-coding genes (DESeq2, P< 0.05, log2 fold-change > |1|) in OCCC with concurrent endometriosis compared to endometriomas. Gene set enrichment analysis showed upregulation of pathways involved in cell cycle regulation and DNA replication and downregulation of pathways involved in cytokine receptor signaling and matrisome. Comparison of pathway activation scores between the clinical samples and publicly-available datasets for OCCC cell lines revealed significant molecular similarities between OCCC with concurrent endometriosis and OVTOKO, OVISE, RMG1, OVMANA, TOV21G, IGROV1, and JHOC5 cell lines. Analysis of miRNAs revealed 64 upregulated and 61 downregulated mature miRNA molecules (DESeq2, P< 0.05, log2 fold-change > |1|). MiR-10a-5p represented over 21% of the miRNA molecules in OCCC with endometriosis and was significantly upregulated (NGS: log2fold change = 4.37, P = 2.43e-18; QPCR: 8.1-fold change, P< 0.05). Correlation between miR-10a expression level in OCCC cell lines and IC50 (50% inhibitory concentration) of carboplatin in vitro revealed a positive correlation (R2 = 0.93). MiR-10a overexpression in vitro resulted in a significant decrease in proliferation (n = 6; P< 0.05) compared to transfection with a non-targeting control miRNA. Similarly, the cell-cycle analysis revealed a significant shift in cells from S and G2 to G1 (n = 6; P< 0.0001). Bioinformatic analysis predicted that miR-10a-5p target genes that were downregulated in OCCC with endometriosis were involved in receptor signaling pathways, proliferation, and cell cycle progression. MiR-10a overexpression in vitro was correlated with decreased expression of predicted miR-10a target genes critical for proliferation, cell-cycle regulation, and cell survival including [SERPINE1 (3-fold downregulated; P< 0.05), CDK6 (2.4-fold downregulated; P< 0.05), and RAP2A (2-3-fold downregulated; P< 0.05)].

Discussion

These studies in OCCC suggest that miR-10a-5p is an impactful, potentially oncogenic molecule, which warrants further studies.

The Intricate Interplay between Cancer Stem Cells and Oncogenic miRNAs in Breast Cancer Progression and Metastasis

Complex signaling interactions between cancer cells and their microenvironments drive the clonal selection of cancer cells. Opposing forces of antitumor and tumorigenic potential regulate the survival of the fittest clones, while key genetic and epigenetic alterations in healthy cells force them to transform, overcome cell senescence, and proliferate in an uncontrolled manner. Both clinical samples and cancer cell lines provide researchers with an insight into the complex structure and hierarchy of cancer. Intratumor heterogeneity allows for multiple cancer cell subpopulations to simultaneously coexist within tumors. One category of these cancer cell subpopulations is cancer stem cells (CSCs), which possess stem-like characteristics and are not easily detectable. In the case of breast cancer, which is the most prevalent cancer type among females, such subpopulations of cells have been isolated and characterized via specific stem cell markers. These stem-like cells, known as breast cancer stem cells (BCSCs), have been linked to major events during tumorigenesis including invasion, metastasis and patient relapse following conventional therapies. Complex signaling circuitries seem to regulate the stemness and phenotypic plasticity of BCSCs along with their differentiation, evasion of immunosurveillance, invasiveness and metastatic potential. Within these complex circuitries, new key players begin to arise, with one of them being a category of small non-coding RNAs, known as miRNAs. Here, we review the importance of oncogenic miRNAs in the regulation of CSCs during breast cancer formation, promotion and metastasis, in order to highlight their anticipated usage as diagnostic and prognostic tools in the context of patient stratification and precision medicine.

Involvement of miRNA on Epigenetics landscape of Parkinson's disease: From pathogenesis to therapeutics

The development of novel therapeutics for the effective management of Parkinson's disease (PD) is undertaken seriously by the scientific community as the burden of PD continues to increase. Several molecular pathways are being explored to identify novel therapeutic targets. Epigenetics is strongly implicated in several neurodegenerative diseases (NDDs) including PD. Several epigenetic mechanisms were found to dysregulated in various studies. These mechanisms are regulated by several miRNAs which are associated with a variety of pathogenic mechanisms in PD. This concept is extensively investigated in several cancers but not well documented in PD. Identifying the miRNAs with dual role i.e., regulation of epigenetic mechanisms as well as modulation of proteins implicated in the pathogenesis of PD could pave way for the development of novel therapeutics to target them. These miRNAs could also serve as potential biomarkers and can be useful in the early diagnosis or assessment of disease severity. In this article we would like to discuss about various epigenetic changes operating in PD and how miRNAs are involved in the regulation of these mechanisms and their potential to be novel therapeutic targets in PD.

Prognostic and immune implications of a novel 7-methylguanosine-related microRNA signature in breast invasive carcinoma: from exploration to validation

OBJECTIVES

This study aims to develop and validate a prognostic signature based on 7-methylguanosine-related (M7G-related) miRNAs for predicting prognosis and immune implications in breast invasive carcinoma (BRCA).

MATERIALS AND METHODS

M7G-related miRNA data of BRCA were obtained from The Cancer Genome Atlas (TCGA). Least absolute shrinkage and selection operator (LASSO)-penalized, univariate, and multivariate Cox regression analyses were used to construct the prognostic signature. Furthermore, the predictive validity was verified using Kaplan-Meier (KM) survival risk and receiver operating characteristic (ROC) plots. Internal random sampling verification was used to simplify and validate the signature. RT-qPCR was used to quantify the expression level of transcriptional profiles. The independent prognostic role of the risk score was validated using univariate and multivariate regression. Single-sample Gene Set Enrichment Analysis (ssGSEA) was used for functional and immune enrichment analysis.

RESULTS

A total of 18 M7G-related miRNAs were identified to construct the prognostic signature in BRCA. The low-risk group exhibited significantly higher overall survival than the high-risk group in the KM survival plot (P < 0.001). The area under the curve (AUC) for 1-, 3-, and 5-year survivals in the ROC curve were 0.737, 0.724, and 0.702, respectively. The survival significance in the training and testing cohorts was confirmed by random sampling verification. The most prominent miRNAs in the signature were the miR-7, miR-139, miR-10b, and miR-4728. Furthermore, immune scores for B, mast, and Th1 cells varied between risk groups. Our research demonstrated that CD52 was the most positively correlated gene with immune cells and functions in BRCA.

CONCLUSION

Our study presents a comprehensive and systematic analysis of M7G-related miRNAs to construct a prognostic signature in BRCA. The signature demonstrated excellent prognostic validity, with the risk score as an independent prognostic factor. These results provide critical evidence for further investigation of M7G miRNAs and offer new insights for BRCA patients in the context of effective immunotherapy.

miR-146a-5p Promotes Angiogenesis and Confers Trastuzumab Resistance in HER2+ Breast Cancer

Trastuzumab treatment has significantly improved the prognosis of HER2-positive breast cancer patients. Despite this, resistance to therapy still remains the main clinical challenge. In order to evaluate the implication of microRNAs in the trastuzumab response, we performed a microRNA array in parental and acquired trastuzumab-resistant HER2-positive breast cancer cell lines. Our results identified miR-146a-5p as the main dysregulated microRNA. Interestingly, high miR-146a-5p expression in primary tumor tissue significantly correlated with shorter disease-free survival in HER2-positive breast cancer patients. The gain- and loss-of-function of miR-146a-5p modulated the response to trastuzumab. Furthermore, the overexpression of miR-146a-5p increased migration and angiogenesis, and promoted cell cycle progression by reducing CDKN1A expression. Exosomes from trastuzumab-resistant cells showed a high level of miR-146a-5p expression compared with the parental cells. In addition, the co-culture with resistant cells’ exosomes was able to decrease in sensitivity and increase the migration capacities in trastuzumab-sensitive cells, as well as angiogenesis in HUVEC-2 cells. Collectively, these data support the role of miR-146a-5p in resistance to trastuzumab, and demonstrate that it can be transferred by exosomes conferring resistance properties to other cells.

Mir-153-3p Modulates the Breast Cancer Cells’ Chemosensitivity to Doxorubicin by Targeting KIF20A

Breast cancer is considered the solid tumor most sensitive to chemotherapy. However, it can become resistant to various chemotherapeutic drugs, including doxorubicin, which triggers cell death by intercalation between DNA bases, free radical formation, and topoisomerase II inhibition. When drug resistance develops, several miRNAs are dysregulated, suggesting that miRNAs may play a significant role in resistance formation. In the current study, we investigated how doxorubicin sensitivity of breast cancer cells is affected by miR-153-3p and its target gene. The MTT method was used to determine the chemo-sensitizing effect of miR-153-3p on doxorubicin in MCF-7 and MDA-MB-231 cell lines. Results of Western blot and dual luciferase confirmed that miR-153-3p targets KIF20A and decreases its expression. Transwell and flow cytometry experiments showed that miR-153-3p and doxorubicin together had higher effects on MCF-7 and MDA-MB-231 cell proliferation, migration, and invasion, as well as increasing apoptosis and arresting cells in the G1 phase. Proteins related to apoptosis and the cell cycle exhibited the same tendency. Intracellular vesicle formation was inhibited and RAB26 was also downregulated by treatment with miR-153-3p alone or in combination with doxorubicin. Doxorubicin’s ability to suppress tumors may be enhanced by miR-153-3p, according to in vivo studies. According to our findings, miR-153-3p has a direct effect on KIF20A and may regulate the formation of intracellular vesicles, which in turn makes breast cancer cells more susceptible to doxorubicin.

miRNAs are now starring in "No Time to Die: Overcoming the chemoresistance in cancer"

Cancer is a leading cause of death globally, with about 19.3 million new cases reported each year. Current therapies for cancer management include-chemotherapy, radiotherapy, and surgery. However, they are loaded with side effects and tend to cause toxicity in the patient's body posttreatment, ultimately hindering the response towards the treatment building up resistance. This is where noncoding RNAs such as miRNAs help provide us with a helping hand for taming the chemoresistance and providing potential holistic cancer management. MicroRNAs are promising targets for anticancer therapy as they perform critical regulatory roles in various signaling cascades related to cell proliferation, apoptosis, migration, and invasion. Combining miRNAs and anticancer drugs and devising a combination therapy has managed cancer well in various independent studies. This review aims to provide insights into how miRNAs play a mechanistic role in cancer development and progression and regulate drug resistance in various types of cancers. Furthermore, next-generation novel therapies using miRNAs in combination with anticancer treatments in multiple cancers have been put forth and how they improve the efficacy of the treatments. Exemplary studies currently in the preclinical and clinical models have been summarized. Ultimately, we briefly talk through the challenges that come forward with it and minimize them.

Exosomal miRNAs as novel avenues for breast cancer treatment

Breast cancer is the most commonly diagnosed cancer and a leading cause of death in women worldwide. It is a heterogeneous disease, as shown by the gene expression profiles of breast cancer samples. It begins in milk-producing ducts, with a high degree of diversity between and within tumors, as well as among cancer-bearing individuals. The enhanced prevalence of breast cancer is influenced by various hormonal, lifestyle, and environmental factors, and very early onset of the disease correlates strongly with the risk of local and distant recurrence. Many subtypes are difficult to treat with conventional therapeutic modalities, and therefore, optimal management and early diagnosis are the first steps to minimizing the mortality linked with breast cancer. The use of newer methods of nanotechnology extends beyond the concept of synthesizing drug delivery mechanisms into the creation of new therapeutics, such as delivering chemotherapeutics with nanomaterial properties. Exosomes, a class of nanovesicles, are emerging as novel tools for deciphering the patient-specific proteins and biomarkers across different disease models, including breast cancer. In this review, we address the role of exosomal miRNA in breast cancer diagnosis and treatment.

MicroRNA-217 aggravates breast cancer through activation of NF1-mediated HSF1/ATG7 axis and c-Jun/ATF3/MMP13 axis

Application of microRNA-mediated mRNA expression in treatment of diverse cancers has been documented. The current study was explored to study the role of miR-217 in breast cancer (BC) progression and the related downstream factors. Clinical tissue samples, BC cell lines and the established xenograft models were prepared for ectopic expression and depletion experiments to discern the regulatory roles of miR-217-mediated NF1 in BC cell proliferation, metastasis and chemoresistance as well as tumorigenic ability of BC cells in nude mice. miR-217 was upregulated in BC, which was a predictor of poor prognosis of BC patients. NF1 could be targeted by miR-217. miR-217 promoted malignant characteristics of BC cells through enhancing ATF3-MMP13 interaction by inhibiting NF1. miR-217 repressed sensitivity against anti-cancer drugs by inducing autophagy of BC cells through the NF1/HSF1/ATG7 axis. Also, miR-217 could inhibit NF1 to facilitate tumorigenic ability of BC cells in vivo. Our study emphasized that miR-217 could potentially inhibit NF1 expression to activate the c-Jun, thus enhancing the expression and interaction of ATF3/MMP13 and promoting the malignant features of BC cells. Furthermore, miR-217 conferred chemoresistance on BC by enhancing BC cell autophagy, which was achieved by limiting NF1 expression to induce the HSF1/ATG7 pathway.

Silencing the expression of lncRNA SNHG15 may be a novel therapeutic approach in human breast cancer through regulating miR-345-5p

BACKGROUND

Long noncoding RNA (lncRNA) short nucleolar RNA host gene 15 (SNHG15) has been found to have an oncogenic function in numerous malignancies. Nevertheless, the biological function and regulatory mechanisms of SNHG15 in breast cancer have not been fully elucidated.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of SNHG15 and in MDA-MB-231 breast cancer cells. The expression of SNHG15 was silenced using small interfering RNA (siRNA) technology. The proliferation and migration of the cells were examined by colony formation assays, cell counting kit 8 (CCK-8) assays, and transwell assays. For the zebrafish xenograft injection experiments, cultured cells labelled with the fluorescent dye CM-DiI were injected into the perivitelline space of the larvae.

RESULTS

This present study revealed that the expression of lncRNA SNHG15 (lnc-SNHG15) was significantly upregulated in breast cancer cells, and its overexpression was associated with the tumor. The relative expression of lnc-SNHG15 could be downregulated using siRNAs, and silencing lnc-SNHG15 inhibited the proliferation and the migration of MDA-MB-231 cells. In vivo experiments using the zebrafish xenograft model showed similar results. Mechanistically, the knockdown effect of lnc-SNHG15 could be restored by inhibiting the expression of the miR-345-5p, confirming the negative regulation between lnc-SNHG15 and miR-345-5p. Interestingly, cisplatin treatment combined with SNHG15 knockdown effectively inhibited MDA-MB-231 cell proliferation and migration in the zebrafish xenograft compared to negative controls.

CONCLUSIONS

In conclusion, lnc-SNHG15 knockdown increased miR-345-5p expression and negated cisplatin resistance in breast cancer cells, and thus, lnc-SNHG15 may be a potential novel target for breast cancer therapy.

Extracellular vesicle miRNAs promote the intestinal microenvironment by interacting with microbes in colitis

Inflammatory bowel disease (IBD) is a global disease with no cure. Disruption of the microbial ecosystem is considered to be an important cause of IBD. Extracellular vesicles (EVs) are vital participants in cell-cell and cell-organism communication. Both host-derived EVs and bacteria-derived membrane vesicles (OMVs) contribute to homeostasis in the intestine. However, the roles of EVs-miRNAs and MVs in host-microbe interactions in colitis remain unclear. In the present study, the animal model of colitis was established by dextran sulfate sodium (DSS) to investigate the changes of miRNAs in colonic EVs from colitis. Several miRNAs were significantly altered in colitis EVs. miR-181b-5p transplantation inhibited M1 macrophage polarization and promoted M2 polarization to reduce the levels of inflammation both in acute and remission of chronic colitis. miR-200b-3p could interact with bacteria and regulate the composition of the microbiota, which contributed to intestinal barrier integrity and homeostasis. Notably, MVs from normal feces could effectively reverse the composition of the intestinal microbiota, restore the intestinal barrier and rescue colitis, and BMVs from colitis would also have similar effects after miR-200b-3p treatment. Our results preliminarily identify a vesicle-based host-microbe interaction cycle in colitis and provide new ideas for colitis treatment.

The role of lncRNA H19 in tumorigenesis and drug resistance of human Cancers

Systemic therapy is one of the most significant cancer treatments. However, drug resistance often appears and has become the primary cause of cancer therapy failure. Regulation of drug target, drug metabolism and drug efflux, cell death escape (apoptosis, autophagy, et al.), epigenetic changes, and many other variables are complicatedly involved in the mechanisms of drug resistance. In various types of cancers, long non-coding RNA H19 (lncRNA H19) has been shown to play critical roles in tumor development, proliferation, metastasis, and multiple drug resistance as well. The efficacy of chemotherapy, endocrine therapy, and targeted therapy are all influenced by the expression of H19, especially in breast cancer, liver cancer, lung cancer and colorectal cancer. Here, we summarize the relationship between lncRNA H19 and tumorigenesis, and illustrate the drug resistance mechanisms caused by lncRNA H19 as well. This review may provide more therapeutic potential targets for future cancer treatments.

Cisplatin Resistance: Genetic and Epigenetic Factors Involved

Cisplatin (CDDP) is the drug of choice against different types of cancer. However, tumor cells can acquire resistance to the damage caused by cisplatin, generating genetic and epigenetic changes that lead to the generation of resistance and the activation of intrinsic resistance mechanisms in cancer cells. Among them, we can find mutations, alternative splicing, epigenetic-driven expression changes, and even post-translational modifications of proteins. However, the molecular mechanisms by which CDDP resistance develops are not clear but are believed to be multi-factorial. This article highlights a description of cisplatin, which includes action mechanism, resistance, and epigenetic factors involved in cisplatin resistance.

2D MOF Nanosensor-Integrated Digital Droplet Microfluidic Flow Cytometry for In Situ Detection of Multiple miRNAs in Single CTC Cells

Current circulating tumor cells (CTCs) detection strategies based on surface epithelial markers suffer from low specificity in distinguishing between CTCs and epithelial cells in hematopoietic cell population. Tumor-associated miRNAs within CTCs are emerging as new biomarkers due to their high correlation with tumor development and progress. However, in-situ simultaneous analysis of multiple miRNAs in single CTC cell is still challenging. To overcome this limitation, a digital droplet microfluidic flow cytometry based on biofunctionalized 2D metal-organic framework nanosensor (Nano-DMFC) is developed for in situ detection of dual miRNAs simultaneously in single living breast cancer cells. Here, 2D MOF-based fluorescent resonance energy transfer (FRET) nanosensors are established by conjugating dual-color fluorescence dye-labeled DNA probes on MOF nanosheet surface. In the Nano-DMFC, 2D MOF-based nanoprobes are precisely microinjected into each single-cell encapsulated droplets to achieve dual miRNA characterization in single cancer cell. This Nano-DMFC platform successfully detects dual miRNAs at single-cell resolution in 10 mixed positive MCF-7 cells out of 10 000 negative epithelial cells in serum biomimic samples. Moreover, this Nano-DMFC platform shows good reproductivity in the recovery experiment of spiked blood samples, which demonstrate the high potential for CTC-based cancer early diagnosis and prognosis.

Prognostic and Predictive Effects of Tumor and Plasma miR-200c-3p in Locally Advanced and Metastatic Breast Cancer

While the role of miR-200c in cancer progression has been established, its expression and prognostic role in breast cancer is not completely understood. The predictive role of miR-200c in response to chemotherapy has also been suggested by some studies, but only limited clinical evidence is available. The purpose of this study was to investigate miR-200c-3p in the plasma and primary tumor of BC patients. The study design included two cohorts involving women with locally advanced (LABC) and metastatic breast cancer. Tumor and plasma samples were obtained before and after treatment. We found that miR-200c-3p was significantly higher in the plasma of BC patients compared with the controls. No correlation of age with plasma miR-200c-3p was found for controls or for BC patients. MiR-200c-3p tumor expression was also associated with poor overall survival in LABC patients treated with neoadjuvant chemotherapy, independently of pathological complete response or clinical stage. Our findings suggest that plasmatic miR-200c-3p levels could be useful for BC staging, while the tumor expression of miR-200c-3p might provide further prognostic information beyond residual disease in BC treated with neoadjuvant chemotherapy.

MicroRNA as a Potential Therapeutic Molecule in Cancer

Small noncoding RNAs, as post-translational regulators of many target genes, are not only markers of neoplastic disease initiation and progression, but also markers of response to anticancer therapy. Hundreds of miRNAs have been identified as biomarkers of drug resistance, and many have demonstrated the potential to sensitize cancer cells to therapy. Their properties of modulating the response of cells to therapy have made them a promising target for overcoming drug resistance. Several methods have been developed for the delivery of miRNAs to cancer cells, including introducing synthetic miRNA mimics, DNA plasmids containing miRNAs, and small molecules that epigenetically alter endogenous miRNA expression. The results of studies in animal models and preclinical studies for solid cancers and hematological malignancies have confirmed the effectiveness of treatment protocols using microRNA. Nevertheless, the use of miRNAs in anticancer therapy is not without limitations, including the development of a stable nanoconstruct, delivery method choices, and biodistribution. The aim of this review was to summarize the role of miRNAs in cancer treatment and to present new therapeutic concepts for these molecules. Supporting anticancer therapy with microRNA molecules has been verified in numerous clinical trials, which shows great potential in the treatment of cancer.

MicroRNAs and drug resistance in colorectal cancer with special focus on 5-fluorouracil

Colorectal cancer is globally one of the most common cancers in all age groups. The current chemotherapy combinations for colorectal cancer treatment include 5-fluorouracil-based regimens; however, drug resistance remains one of the main reasons for chemotherapy failure and disease recurrence. Many studies have determined colorectal cancer chemoresistance mechanisms such as drug efflux, cell cycle arrest, DNA damage repair, apoptosis, autophagy, vital enzymes, epigenetic, epithelial-mesenchymal transition, stem cells, and immune system suppression. Several microRNAs affect drug resistance by regulating the drug resistance-related target genes in colorectal cancer. These drug resistance-related miRNAs may be used as promising biomarkers for predicting drug response or as potential therapeutic targets for treating patients with colorectal cancer. This work reviews and discuss the role of selected microRNAs in 5-fluorouracil resistance and their molecular mechanisms in colorectal cancer.

siRNA-Based Carrier-Free System for Synergistic Chemo/Chemodynamic/RNAi Therapy of Drug-Resistant Tumors

Multiple drug-resistance mechanisms originate from defensive pathways in cancer and are associated with the unsatisfied efficacy of chemotherapy. The combination of small interfering RNA (siRNA) and chemotherapeutics provides a strategy for reducing drug efflux but requires more delivery options for clinical translation. Herein, multidrug resistance protein 1 (MDR1) siRNA is used as the skeleton to assemble chemotherapeutic cisplatin (CDDP) and divalent copper ion (Cu²⁺) for constructing a carrier-free Cu-siMDR-CDDP system. Cu-siMDR-CDDP specifically responds and disassembles in the acidic tumor microenvironment (TME). The released CDDP activates cascade bioreactions of NADPH oxidases and superoxide dismutase to generate hydrogen peroxide (H₂O₂). Then a Cu²⁺-catalyzed Fenton-like reaction transforms H₂O₂ to hydroxyl radicals (HO^•) and causes glutathione (GSH) depletion to disrupt the redox adaptation mechanism of drug-resistant cancer cells. Besides, delivery of MDR1 siRNA is facilitated by HO^•-triggered lysosome destruction, thus inhibiting P-glycoprotein (P-gp) expression and CDDP efflux. The unique design of Cu-siMDR-CDDP is to exploit siRNA as building blocks in regulating the self-assembly behavior, and integration of functional units simultaneously alleviates limitations caused by drug-resistance mechanisms. Such a carrier-free system shows synergistic chemo/chemodynamic/RNA interference therapy in suppressing tumor growth in vivo and has the reference value for overcoming drug resistance.

Crosstalk between non-coding RNAs expression profile, drug resistance and immune response in breast cancer

Drug resistance is one of the most critical challenges facing researchers in treating breast cancer. Despite numerous treatments for breast cancer, including conventional chemical drugs, monoclonal antibodies, and immunotherapeutic drugs known as immune checkpoint inhibitors (ICI), many patients resist various approaches. In recent years, the relationship between gene expression profiles and drug resistance phenotypes has attracted much attention. Non-coding RNAs (ncRNAs) are regulatory molecules that have been shown to regulate gene expression and cell transcriptome. Two categories, microRNAs and long non-coding RNAs have been more considered and studied among these ncRNAs. Studying the role of different ncRNAs in chemical drug resistance and ICI resistance together can be beneficial in selecting more effective treatments for breast cancer. Changing the expression and action mechanism of these regulatory molecules on drug resistance phenotypes is the main topic of this review article.

Emerging Role of miR-345 and Its Effective Delivery as a Potential Therapeutic Candidate in Pancreatic Cancer and Other Cancers

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with high mortality, poor prognosis, and palliative treatments, due to the rapid upregulation of alternative compensatory pathways and desmoplastic reaction. miRNAs, small non-coding RNAs, have been recently identified as key players regulating cancer pathogenesis. Dysregulated miRNAs are associated with molecular pathways involved in tumor development, metastasis, and chemoresistance in PDAC, as well as other cancers. Targeted treatment strategies that alter miRNA levels in cancers have promising potential as therapeutic interventions. miRNA-345 (miR-345) plays a critical role in tumor suppression and is differentially expressed in various cancers, including pancreatic cancer (PC). The underlying mechanism(s) and delivery strategies of miR-345 have been investigated by us previously. Here, we summarize the potential therapeutic roles of miR-345 in different cancers, with emphasis on PDAC, for miRNA drug discovery, development, status, and implications. Further, we focus on miRNA nanodelivery system(s), based on different materials and nanoformulations, specifically for the delivery of miR-345.

The E3 Ubiquitin Ligase NEDD4-1 Mediates Temozolomide-Resistant Glioblastoma through PTEN Attenuation and Redox Imbalance in Nrf2-HO-1 Axis

BACKGROUND

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. It is highly resistant to chemotherapy, and tumor recurrence is common. Neuronal precursor cell-expressed developmentally downregulated 4-1 (NEDD4-1) is an E3 ligase that controls embryonic development and animal growth. NEDD4-1 regulates the tumor suppressor phosphatase and tensin homolog (PTEN), one of the major regulators of the PI3K/AKT/mTOR signaling axis, as well as the response to oxidative stress.

METHODS

The expression levels of NEDD4-1 in GBM tissues and different cell lines were determined by quantitative real-time polymerase chain reaction and immunohistochemistry. In vitro and in vivo assays were performed to explore the biological effects of NEDD4-1 on GBM cells. Temozolomide (TMZ)-resistant U87MG and U251 cell lines were specifically established to determine NEDD4-1 upregulation and its effects on the tumorigenicity of GBM cells. Subsequently, miRNA expression in TMZ-resistant cell lines was investigated to determine the dysregulated miRNA underlying the overexpression of NEDD4-1. Indole-3-carbinol (I3C) was used to inhibit NEDD4-1 activity, and its effect on chemoresistance to TMZ was verified.

RESULTS

NEDD4-1 was significantly overexpressed in the GBM and TMZ-resistant cells and clinical samples. NEDD4-1 was demonstrated to be a key oncoprotein associated with TMZ resistance, inducing oncogenicity and tumorigenesis of TMZ-resistant GBM cells compared with TMZ-responsive cells. Mechanistically, TMZ-resistant cells exhibited dysregulated expression of miR-3129-5p and miR-199b-3p, resulting in the induced NEDD4-1 mRNA-expression level. The upregulation of NEDD4-1 attenuated PTEN expression and promoted the AKT/NRF2/HO-1 oxidative stress signaling axis, which in turn conferred amplified defense against reactive oxygen species (ROS) and eventually higher resistance against TMZ treatment. The combination treatment of I3C, a known inhibitor of NEDD4-1, with TMZ resulted in a synergistic effect and re-sensitized TMZ-resistant tumor cells both in vitro and in vivo.

CONCLUSIONS

These findings demonstrate the critical role of NEDD4-1 in regulating the redox imbalance in TMZ-resistant GBM cells via the degradation of PTEN and the upregulation of the AKT/NRF2/HO-1 signaling pathway. Targeting this regulatory axis may help eliminate TMZ-resistant glioblastoma.

MicroRNAs as a clue to overcome breast cancer treatment resistance

Breast cancer is the most frequent cancer in women worldwide. Despite the improvement in diagnosis and treatments, the rates of cancer relapse and resistance to therapies remain higher than desirable. Alterations in microRNAs have been linked to changes in critical processes related to cancer development and progression. Their involvement in resistance or sensitivity to breast cancer treatments has been documented by different in vivo and in vitro experiments. The most significant microRNAs implicated in modulating resistance to breast cancer therapies are summarized in this review. Resistance to therapy has been linked to cellular processes such as cell cycle, apoptosis, epithelial-to-mesenchymal transition, stemness phenotype, or receptor signaling pathways, and the role of microRNAs in their regulation has already been described. The modulation of specific microRNAs may modify treatment response and improve survival rates and cancer patients' quality of life. As a result, a greater understanding of microRNAs, their targets, and the signaling pathways through which they act is needed. This information could be useful to design new therapeutic strategies, to reduce resistance to the available treatments, and to open the door to possible new clinical approaches.

Resistance to Intervention: Paclitaxel in Breast Cancer

Breast cancer stands as the most prevalent cancer in women globally, and contributes to the highest percentage of mortality due to cancer-related deaths in women. Paclitaxel (PTX) is heavily relied on as a frontline chemotherapy drug in breast cancer treatment, especially in advanced metastatic cancer. Generation of resistance to PTX often derails clinical management and adversely affects patient outcomes. Understanding the molecular mechanism of PTX resistance is necessary to device methods to aid in overcoming the resistance. Recent studies exploring the mechanism of development of PTX resistance have led to unveiling of a range novel therapeutic targets. PTX resistance pathways that involve major regulatory proteins/RNAs like RNF8/Twist/ROR1, TLR, ErbB3/ErbB2, BRCA1- IRIS, MENA, LIN9, MiRNA, FoxM1 and IRAK1 have expanded the complexity of resistance mechanisms, and brought newer insights into the development of drug targets. These resistance-related targets can be dealt with synthetic/natural therapeutics in combination with PTX. The present review encompasses the recent understanding of PTX resistance mechanisms in breast cancer and possible therapeutic combinations to overcome resistance.

Breast Cancer Drug Resistance: Overcoming the Challenge by Capitalizing on MicroRNA and Tumor Microenvironment Interplay

The clinical management of breast cancer reaches new frontiers every day. However, the number of drug resistant cases is still high, and, currently, this constitutes one of the major challenges that cancer research has to face. For instance, 50% of women affected with HER2 positive breast cancer presents or acquires resistance to trastuzumab. Moreover, for patients affected with triple negative breast cancer, standard chemotherapy is still the fist-line therapy, and often patients become resistant to treatments. Tumor microenvironment plays a crucial role in this context. Indeed, cancer-associated stromal cells deliver oncogenic cues to the tumor and vice versa to escape exogenous insults. It is well known that microRNAs are among the molecules exploited in this aberrant crosstalk. Indeed, microRNAs play a crucial function both in the induction of pro-tumoral traits in stromal cells and in the stroma-mediated fueling of tumor aggressiveness. Here, we summarize the most recent literature regarding the involvement of miRNAs in the crosstalk between tumor and stromal cells and their capability to modulate tumor microenvironment characteristics. All up-to-date findings suggest that microRNAs in the TME could serve both to reverse malignant phenotype of stromal cells, modulating response to therapy, and as predictive/prognostic biomarkers.

MicroRNAs: The Link between the Metabolic Syndrome and Oncogenesis

Metabolic syndrome (MetS) represents a cluster of disorders that increase the risk of a plethora of conditions, in particular type two diabetes, cardiovascular diseases, and certain types of cancers. MetS is a complex entity characterized by a chronic inflammatory state that implies dysregulations of adipokins and proinflammatory cytokins together with hormonal and growth factors imbalances. Of great interest is the implication of microRNA (miRNA, miR), non-coding RNA, in cancer genesis, progression, and metastasis. The adipose tissue serves as an important source of miRs, which represent a novel class of adipokines, that play a crucial role in carcinogenesis. Altered miRs secretion in the adipose tissue, in the context of MetS, might explain their implication in the oncogenesis. The interplay between miRs expressed in adipose tissue, their dysregulation and cancer pathogenesis are still intriguing, taking into consideration the fact that miRNAs show both carcinogenic and tumor suppressor effects. The aim of our review was to discuss the latest publications concerning the implication of miRs dysregulation in MetS and their significance in tumoral signaling pathways. Furthermore, we emphasized the role of miRNAs as potential target therapies and their implication in cancer progression and metastasis.

miR-324-3p and miR-508-5p expression levels could serve as potential diagnostic and multidrug-resistant biomarkers in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is one of the most frequent hematological malignancies in children, representing approximately 25 % of all pediatric cancers. Despite striking advances in ALL treatments, a small population of patients does not still respond to chemotherapy, raising the number of deaths in children. ABC transporters are one of the major causes of multidrug resistance (MDR) in cancers and overexpression of ABCA3 is directly associated with increased chemo-resistance in pediatric ALL. Here, we aimed to identify the microRNAs (miRNAs) which may regulate the expression of ABCA3 in childhood ALL. Bone marrow samples from a total of 50 ALLs and 59 controls were collected and after in silico and literature search, miR-324-3p and miR-508-5p were nominated from a list of putative miRNAs targeting ABCA3. Our qPCR analysis showed a low expression profile of selected miRNAs in pediatric ALL patients compared with non-cancer controls. Furthermore, we found that both miR-324-3p and miR-508-5p were significantly differentially expressed between patients with positive and negative minimal residual disease (MRD + vs MRD-) after one year of chemotherapy while only miR-508-5p was underexpressed in relapsed ALL patients. Additionally, a negative correlation was identified between the expression of these two miRNAs and ABCA3, supporting the regulatory effect of them on drug resistance through interacting with ABCA3. Overall, we suggested miR-324-3p and miR-508-5p as potential diagnostic and drug-resistant biomarkers in pediatric ALL. Moreover, our findings presented miR-508-5p to behave as a promising relapsed indicator in childhood ALL which can be applied in the development of novel therapeutic strategies.

lncMat2B regulated by severe hypoxia induces cisplatin resistance by increasing DNA damage repair and tumor-initiating population in breast cancer cells

Multicellular tumor spheroids (MCTSs) constitute a three-dimensional culture system that recapitulates the in vivo tumor microenvironment. Tumor cells cultured as MCTSs present antineoplastic resistance due to the effect of microenvironmental signals acting upon them. In this work, we evaluated the biological function of a new microenvironment-regulated long non-coding RNA, lncMat2B, in breast cancer. In MCTSs, the expression of lncMat2B presented an increase and a zonal heterogeneity, as it was expressed principally in quiescent cells of hypoxic regions of the MCTSs. As expected, functional assays supported the role of severe hypoxia in the regulation of lncMat2B. Moreover, gain- and loss-of-function assays using a transcriptional silencing CRISPR/Cas9 system and gBlock revealed that lncMAT2B regulates the tumor-initiating phenotype. Interestingly, lncMat2B is overexpressed in a cisplatin-resistant MCF-7 cell line, and its ectopic expression in wild type MCF-7 cells increased survival to cisplatin exposure by reducing DNA damage and reactive oxygen species accumulation. lncMAT2B is a possible link between severe hypoxia, tumor-initiating phenotype and drug resistance in breast cancer cells.

miRNAs Modulate the Dichotomy of Cisplatin Resistance or Sensitivity in Breast Cancer: An Update of Therapeutic Implications

Cisplatin has a broad-spectrum antitumor activity and is widely used for the treatment of various malignant tumors. However, acquired or intrinsic resistance of cisplatin is a major problem for patients during the therapy. Recently, it has been reported Cancer Stem Cell (CSC)-derived drug resistance is a great challenge of tumor development and recurrence; therefore, the sensitivity of Breast Cancer Stem Cells (BCSCs) to cisplatin is of particular importance. Increasing evidence has shown that there is a relationship between cisplatin resistance/sensitivity genes and related miRNAs. It is known that dysregulation of relevant miRNAs plays a critical role in regulating target genes of cisplatin resistance/sensitivity in various pathways such as cellular uptake/efflux, Epithelial-Mesenchymal Transition (EMT), hypoxia, and apoptosis. Furthermore, the efficacy of the current chemotherapeutic drugs, including cisplatin, for providing personalized medicine, can be improved by controlling the expression of miRNAs. Thus, potential targeting of miRNAs can lead to miRNA-based therapies, which will help overcome drug resistance and develop more effective personalized anti-cancer and cotreatment strategies in breast cancer. In this review, we summarized the general understandings of miRNAregulated biological processes in breast cancer, particularly focused on the role of miRNA in cisplatin resistance/ sensitivity.

Identification of miRNA Signature in Breast Cancer to Predict Neoadjuvant Chemotherapy Response

Background: Chemotherapy failure causes high breast cancer recurrence and poor patient prognosis. Thus, we studied a cohort of novel biomarkers to predict chemotherapeutic response in breast cancer. In this study, miRNA expression profiling was performed on 10 breast cancer punctured specimens sensitive to chemotherapy (MP grade 4, 5) and 10 chemotherapy resistant (MP grade 1). Differentially expressed miRNAs were verified by qRT-PCR in 60 initial samples, 59 validated samples and 71 independent samples. A miRNA signature was generated using a Logistic regression model. A receiver operating characteristic (ROC) test was used to assess specificity and sensitivity of single miRNA and miRNA signature. Target genes regulated by miRNAs and their involved signaling pathways were analyzed using GO enrichment and KEGG software. MiRNAs expression were separately compared with ER, PR, HER2 immunohistochemical staining and different drugs. qRT-PCR showed that the high expression of miR-23a-3p, miR-200c-3p, miR-214-3p and the low expression of miR-451a and miR-638 were closely related to chemoresistance. According to the formula for calculating the drug resistance risk, patients in the high-risk group were more likely to develop chemotherapy resistance than the low-risk group. Bioinformatics analysis showed that 5 miRNAs and target genes are mainly involved in p53, ubiquitin-mediated proteolysis, mTOR, Wnt, cells skeletal protein regulation, cell adhesion and ErbB signaling pathways. miR-451a expression was associated with ER, HER-2 status and anthracyclines. A miRNA signature of chemotherapeutic response may be clinically valuable for improving current chemotherapy regimens of individual treatment for patients with breast cancer.

CircZNF208 enhances the sensitivity to X-rays instead of carbon-ions through the miR-7-5p /SNCA signal axis in non-small-cell lung cancer cells

BACKGROUND

Mounting evidence suggests that circular RNAs (circRNAs) are closely related to the regulation of gene expression during tumour development. However, the role of circRNAs in modulating the radiosensitivity of non-small cell lung cancer (NSCLC) cells has not been explored.

METHODS

Transcriptome sequencing was used to explore the expression profiles of circRNAs in NSCLC. The expression level of circRNAs was changed by inducing instantaneous knockdown or overexpression. Changes in proliferation and radiosensitivity of NSCLC cells were investigated using CCK-8, EDU, and clonal survivals.

RESULTS

By analysing the circRNA expression profile of NSCLC cells, we found that circRNA ZNF208 (circZNF208) was significantly upregulated in a radioresistant NSCLC cell line (A549-R11), which was acquired from the parental NSCLC cell line A549. Knockout experiments indicated that circZNF208 enhanced the radiosensitivity of A549 and A549-R11 cells to X-rays. Mechanistically, circZNF208 upregulated SNCA expression by acting as a sponge of miR-7-5p and subsequently promoted the resistance of NSCLC cells to low linear energy transfer (LET) X-rays. However, this effect was not observed in NSCLC cells exposed to high-LET carbon ions.

CONCLUSIONS

Knockdown of circZNF208 altered the radiosensitivity of patients with NSCLC to X-rays but did not significantly change the sensitivity to carbon ions. Therefore, circZNF208 might serve as a potential biomarker and therapeutic target for NSCLC treatment with radiotherapy of different modalities.

Exosomal microRNAs: Pleiotropic Impacts on Breast Cancer Metastasis and Their Clinical Perspectives

As a major threat factor for female health, breast cancer (BC) has garnered a lot of attention for its malignancy and diverse molecules participating in its carcinogenesis process. Among these complex carcinogenesis processes, cell proliferation, epithelial-to-mesenchymal transition (EMT), mesenchymal-to-epithelial transition (MET), and angiogenesis are the major causes for the occurrence of metastasis and chemoresistance which account for cancer malignancy. MicroRNAs packaged and secreted in exosomes are termed "exosomal microRNAs (miRNAs)". Nowadays, more researches have uncovered the roles of exosomal miRNAs played in BC metastasis. In this review, we recapitulated the dual actions of exosomal miRNAs exerted in the aggressiveness of BC by influencing migration, invasion, and distant metastasis. Next, we presented how exosomal miRNAs modify angiogenesis and stemness maintenance. Clinically, several exosomal miRNAs can govern the transformation between drug sensitivity and chemoresistance. Since the balance of the number and type of exosomal miRNAs is disturbed in pathological conditions, they are able to serve as instructive biomarkers for BC diagnosis and prognosis. More efforts are needed to connect the theoretical studies and clinical traits together. This review provides an outline of the pleiotropic impacts of exosomal miRNAs on BC metastasis and their clinical implications, paving the way for future personalized drugs.

Upregulating the Expression of LncRNA ANRIL Promotes Osteogenesis via the miR-7-5p/IGF-1R Axis in the Inflamed Periodontal Ligament Stem Cells

Background

Long non-coding RNA (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) is a base length of about 3.8 kb lncRNA, which plays an important role in several biological functions including cell proliferation, migration, and senescence. This study ascertained the role of lncRNA ANRIL in the senescence and osteogenic differentiation of inflamed periodontal ligament stem cells (iPDLSCs).

Methods

Healthy periodontal ligament stem cells (hPDLSCs) and iPDLSCs were isolated from healthy/inflamed periodontal ligament tissues, respectively. The proliferation abilities were determined by CCK-8, EdU assay, and flow cytometry (FCM). The methods of Western blot assay (WB), quantitative real-time polymerase chain reaction (qRT-PCR), alizarin red staining, alkaline phosphatase (ALP) staining, ALP activity detection, and immunofluorescence staining were described to determine the biological influences of lncRNA ANRIL on iPDLSCs. Senescence-associated (SA)-β-galactosidase (gal) staining, Western blot analysis, and qRT-PCR were performed to determine cell senescence. Dual-luciferase reporter assays were conducted to confirm the binding of lncRNA ANRIL and miR-7-5-p, as well as miR-7-5p and insulin-like growth factor receptor (IGF-1R).

Results

HPDLSCs and iPDLSCs were isolated and cultured successfully. LncRNA ANRIL and IGF-1R were declined, while miR-7-5p was upregulated in iPDLSCs compared with hPDLSCs. Overexpression of ANRIL enhanced the osteogenic protein expressions of OSX, RUNX2, ALP, and knocked down the aging protein expressions of p16, p21, p53. LncRNA ANRIL could promote the committed differentiation of iPDLSCs by sponging miR-7-5p. Upregulating miR-7-5p inhibited the osteogenic differentiation of iPDLSCs. Further analysis identified IGF-1R as a direct target of miR-7-5p. The direct binding of lncRNA ANRIL and miR-7-5p, miR-7-5p and the 3′-UTR of IGF-1R were verified by dual-luciferase reporter assay. Besides, rescue experiments showed that knockdown of miR-7-5p reversed the inhibitory effect of lncRNA ANRIL deficiency on osteogenesis of iPDLSCs.

Conclusion

This study disclosed that lncRNA ANRIL promotes osteogenic differentiation of iPDLSCs by regulating the miR-7-5p/IGF-1R axis.

The Role of miRNA-7 in the Biology of Cancer and Modulation of Drug Resistance

MicroRNAs (miRNAs, miRs) are small non-coding RNA (ncRNA) molecules capable of regulating post-transcriptional gene expression. Imbalances in the miRNA network have been associated with the development of many pathological conditions and diseases, including cancer. Recently, miRNAs have also been linked to the phenomenon of multidrug resistance (MDR). MiR-7 is one of the extensively studied miRNAs and its role in cancer progression and MDR modulation has been highlighted. MiR-7 is engaged in multiple cellular pathways and acts as a tumor suppressor in the majority of human neoplasia. Its depletion limits the effectiveness of anti-cancer therapies, while its restoration sensitizes cells to the administered drugs. Therefore, miR-7 might be considered as a potential adjuvant agent, which can increase the efficiency of standard chemotherapeutics.

The clinical significance of Notch1 immunoexpression in Caucasian patients with colorectal adenocarcinoma

Introduction

Colorectal cancer (CRC) is traditionally regarded as the most commonly diagnosed gastrointestinal malignant disease. Nevertheless, despite advances in diagnosis and novel therapeutic options, the clinical outcomes of patients are still not satisfactory.

Aim

To investigate the clinicopathological and prognostic roles of Notch1 expression, the immunohistochemical investigation was performed in samples of CRC tumour tissues, adjacent non-pathological mucosa, and metastatic foci in regional lymph nodes in Caucasian patients.

Material and methods

Paraffin-embedded adenocarcinoma samples were assessed immunohistochemically for Notch1 protein and scored according to the percentage of cells with a positive reaction combined with staining intensity. Connections between Notch1 immunoexpression and clinicopathological factors including the 5-year overall survival (OS) were evaluated.

Results

The level of the Notch1 immunohistochemical reactivity was correlated with the grade of the histological differentiation, size of the primary tumour, regional lymph node involvement, and perineural invasion (all p < 0.001). Kaplan-Meier survival analysis showed that the survival time for patients with a low expression of Notch1 was significantly longer than that for patients with moderate or strong level of Notch1 immunoreactivity (p < 0.001).

Conclusions

The enhanced level of Notch1 immunoexpression was significantly associated with malignancy-related clinicopathological factors and reduced the 5-year overall survival in CRC patients.

Intercalation of curcumin into liposomal chemotherapeutic agent augments apoptosis in breast cancer cells

Resistance to common chemotherapeutic agents is a frequent phenomenon in late-stage breast cancers. An ideal system capable of the co-delivery of hydrophobic and hydrophilic chemotherapeutic agents can regulate the dosage and co-localization of pharmaceutical compounds and thereby improve the anticancer efficacy. Here, for the first time, we have intercalated curcumin (Cur) into a double-layered membrane of cisplatin (Cis) liposomes to obtain a dosage controlled co-delivery formulation, capable of inducing apoptosis in breast cancer cells. The concentrations of Cur and Cis in nanoliposome (Cur-Cis@NLP) were optimized by response surface methodology (RSM); RSM optimization showed 99.81 and 23.86% entrapment efficiency for Cur and Cis, respectively. TEM analysis demonstrated the fabrication of nanoparticles with average diameter of 100 nm. The anticancer and apoptotic effects of Cur-Cis@NLPs were also evaluated using MTT assay, fluorescent staining and flow cytometry assays. Cytotoxicity assessments of various Cur-Cis@NLPs concentrations demonstrated a concentration-dependent manner. In comparison to free and liposomal Cis, Cur-Cis@NLP reduced breast cancer cells' viability (82.5%) in a significant manner at a final concentration of 32 μg.mL^-1 and 20 μg.mL^-1 of Cur and Cis, respectively. Combination index values calculation of Cur-Cis@NLP showed an overall CI value <1, indicating synergetic effect of the designed co-delivery system. Additionally, flow cytometry assay demonstrated Cur-Cis@NLPs triggered apoptosis about 10-folds higher than liposomal Cis. This co-drug delivery system has a potential for the encapsulation and release of both hydrophobic and hydrophilic drugs, while taking the advantages of the reduced cytotoxic effect along with achieving high potency.

The role of Krüppel-like factor 8 in cancer biology: Current research and its clinical relevance

Cancer is one of the leading causes of mortality worldwide, ranked second after heart disease. Despite recent advancements in diagnosis and treatment, there are still numerous problems associated with cancer progression, disease recurrence, and therapeutic resistance that are partially explored. Several studies have recently revealed that Krüppel-like factor 8 (KLF8) regulates transcription of genes linked with diverse biological processes, including proliferation, epithelial to mesenchymal transition (EMT), migration, invasion, and inflammation. KLF8 is expressed ubiquitously in mammalian cells, and its aberrant expression has been manifested with several cancer types. Earlier studies demonstrated the crucial role of KLF8 in DNA repair and resistance to apoptosis in numerous cancer types. Hence, studying the function of KLF8 from the perspective of cancer progression and therapy resistance would help develop a new therapeutic avenue. In this review, we summarize the clinical relevance of KLF8 expression in various malignancies, focusing on recent updates in EMT, cellular signaling, and cancer stem cells. We also address the contribution of KLF8 in development, DNA repair, chemoresistance, and its clinical utility as a predictive biomarker.

Regulatory Mechanisms of Epigenetic miRNA Relationships in Human Cancer and Potential as Therapeutic Targets

Simple Summary

By the virtue of targeting multiple genes, a microRNA (miRNA) can infer variable consequences on tumorigenesis by appearing as both a tumour suppressor and oncogene. miRNAs can regulate gene expression by modulating genome-wide epigenetic status of genes that are involved in various cancers. These miRNAs perform direct inhibition of key mediators of the epigenetic machinery, such as DNA methyltransferases (DNMTs) and histone deacetylases (HDACs) genes. Along with miRNAs gene expression, similar to other protein-coding genes, miRNAs are also controlled by epigenetic mechanisms. Overall, this reciprocal interaction between the miRNAs and the epigenetic architecture is significantly implicated in the aberrant expression of miRNAs detected in various human cancers. Comprehensive knowledge of the miRNA-epigenetic dynamics in cancer is essential for the discovery of novel anticancer therapeutics.

Abstract

Initiation and progression of cancer are under both genetic and epigenetic regulation. Epigenetic modifications including alterations in DNA methylation, RNA and histone modifications can lead to microRNA (miRNA) gene dysregulation and malignant cellular transformation and are hereditary and reversible. miRNAs are small non-coding RNAs which regulate the expression of specific target genes through degradation or inhibition of translation of the target mRNA. miRNAs can target epigenetic modifier enzymes involved in epigenetic modulation, establishing a trilateral regulatory “epi–miR–epi” feedback circuit. The intricate association between miRNAs and the epigenetic architecture is an important feature through which to monitor gene expression profiles in cancer. This review summarises the involvement of epigenetically regulated miRNAs and miRNA-mediated epigenetic modulations in various cancers. In addition, the application of bioinformatics tools to study these networks and the use of therapeutic miRNAs for the treatment of cancer are also reviewed. A comprehensive interpretation of these mechanisms and the interwoven bond between miRNAs and epigenetics is crucial for understanding how the human epigenome is maintained, how aberrant miRNA expression can contribute to tumorigenesis and how knowledge of these factors can be translated into diagnostic and therapeutic tool development.

Connecting the Missing Dots: ncRNAs as Critical Regulators of Therapeutic Susceptibility in Breast Cancer

Whether acquired or de novo, drug resistance remains a significant hurdle in achieving therapeutic success in breast cancer (BC). Thus, there is an urge to find reliable biomarkers that will help in predicting the therapeutic response. Stable and easily accessible molecules such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are regarded as valuable prognostic biomarkers and therapeutic targets since they act as crucial regulators of the various mechanisms involved in BC drug resistance. Here, we reviewed the current literature on ncRNAs as mediators of resistance to systemic therapies in BC. Interestingly, upon integrating data results from individual studies, we concluded that miR-221, miR-222, miR-451, Urothelial Carcinoma Associated 1 (UCA1), and Growth arrest-specific 5 (GAS5) are strong candidates as prognostic biomarkers and therapeutic targets since they are regulating multiple drug resistance phenotypes in BC. However, further research around their clinical implications is needed to validate and integrate them into therapeutic applications. Therefore, we believe that our review may provide relevant evidence for the selection of novel therapeutic targets and prognostic biomarkers for BC and will serve as a foundation for future translational research in the field.

MicroRNAs in breast cancer: New maestros defining the melody

MicroRNAs, short non-coding single-stranded RNAs, are important regulators and gatekeepers of the coding genes in the human genome. MicroRNAs are highly conserved among species and expressed in different tissues and cell types. They are involved in almost all the biological processes as apoptosis, proliferation, cell cycle arrest and differentiation. Playing all these roles, it is not surprising that the deregulation of the microRNA profile causes a number of diseases including cancer. Breast cancer, the most commonly diagnosed malignancy in women, accounts for the highest cancer-related deaths worldwide. Different microRNAs were shown to be up or down regulated in breast cancer. MicroRNAs can function as oncogenes or tumor suppressors according to their targets. In this review, the most common microRNAs implicated in breast cancer are fully illustrated with their targets. Besides, the review highlights the effect of exosomal microRNA on breast cancer and the effect of microRNAs on drug and therapies resistance as well as the miRNA-based therapeutic strategies used until today.

De novo methyltransferases: Potential players in diseases and new directions for targeted therapy

Epigenetic modifications govern gene expression by guiding the human genome on 'what to express and what not to'. DNA methyltransferases (DNMTs) establish methylation patterns on DNA, particularly in CpG islands, and such patterns play a major role in gene silencing. DNMTs are a family of proteins/enzymes (DNMT1, 2, 3A, 3B, and 3L), among which, DNMT1 (maintenance methyltransferase) and DNMT3 (de novo methyltransferases) that direct mammalian development and genome imprinting are highly investigated. In recent decades, many studies revealed a strong association of DNA methylation patterns with gene expression in various clinical conditions. Differential expression of DNMT3 family proteins and their splice variants result in changes in methylation patterns and such alterations have been associated with the initiation and progression of various diseases, especially cancer. This review will discuss the aberrant modifications generated by DNMT3 proteins under various clinical conditions, suggesting a potential signature for de novo methyltransferases in targeted disease therapy. Further, this review discusses the possibility of using 'CpG island methylation signatures' as promising biomarkers and emphasizes 'targeted hypomethylation' by disrupting the interaction of specific DNMT-protein complexes as the future of cancer therapeutics.