miR-513a-3p sensitizes human lung adenocarcinoma cells to chemotherapy by targeting GSTP1

Functional combination of resveratrol and tamoxifen to overcome tamoxifen-resistance in breast cancer cells

Researchers are encountering challenges in addressing the issue of cancer cells becoming unresponsive to various chemotherapy treatments due to drug resistance. This study was designed to study the influence of antioxidant resveratrol (RSV) to sensitize resistant breast cancer (BC) cells toward tamoxifen (TAM). The cytotoxic effects of RSV and TAM against TAM-resistant LCC2 cells and their parental michigan cancer foundation-7 BC cells were determined by sulphorhodamine B assay. Further, the expression levels of multidrug resistance (MDR) genes including ABCB1, ABCC2, ABCG2, and MRP1 using quantitative polymerase chain reaction, apoptosis induction, and reactive oxygen species (ROS) content using flow cytometry were evaluated in either LCC2 cells treated with RSV, TAM, or their combination. The obtained results showed that resistant cells have a magnificent level of MDR genes. This elevated expression dramatically lowered upon receiving the combined therapy of RSV and TAM. Additionally, our work assessed the possible role of RSV in modulating the expression of MDR genes by controlling the expression of certain microRNAs (miRNAs) that target ATP-binding cassette (ABC) transporters. According to the obtained data, the TAM and RSV combination increased the expression of tumor inhibitor miRNAs such miR-10b-3p, miR-195-3p, and miR-223-3p, which made LCC2 cells more sensitive to TAM. Furthermore, this combination showed an elevation in apoptotic levels and total ROS content. The combination between RSV and TAM could be a functional therapy in the fight against TAM-resistant BC cells via modulating miRNA and ABC transporters.

Genome-wide study of glutathione transferases and their regulation in flufenacet susceptible and resistant black-grass (Alopecurus myosuroides Huds.)

BACKGROUND

Glutathione transferases (GSTs) are enzymes with a wide range of functions, including herbicide detoxification. Up-regulation of GSTs and their detoxification activity enables the grass weed black-grass (Alopecurus myosuroides Huds.) to metabolize the very-long-chain fatty acid synthesis inhibitor flufenacet and other herbicides leading to multiple herbicide resistance. However, the genomic organization and regulation of GSTs genes is still poorly understood.

RESULTS

In this genome-wide study the location and expression of 115 GSTs were investigated using a recently published black-grass genome. Particularly, the most abundant GSTs of class tau and phi were typically clustered and often followed similar expression patterns but possessed divergent upstream regulatory regions. Similarities were found in the promoters of the most up-regulated GSTs, which are located next to each other in a cluster. The binding motif of the E2F/DP transcription factor complex in the promoter of an up-regulated GST was identical in susceptible and resistant plants, however, adjacent sequences differed. This led to a stronger binding of proteins to the motif of the susceptible plant, indicating repressor activity.

CONCLUSIONS

This study constitutes the first analysis dealing with the genomic investigation of GST genes found in black-grass and their transcriptional regulation. It highlights the complexity of the evolution of GSTs in black-grass, their duplication and divergence over time. The large number of GSTs allows weeds to detoxify a broad spectrum of herbicides. Ultimately, more research is needed to fully elucidate the regulatory mechanisms of GST expression. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Noncoding RNAs in cancer ferroptosis: From biology to clinical opportunity

Ferroptosis is a recently discovered pattern of programmed cell death that is nonapoptotic and irondependent. It is involved in lipid peroxidation dependent on reactive oxygen species. Ferroptosis has been verified to play a crucial regulatory role in a variety of pathological courses of disease, in particularly cancer. Emerging research has highlighted the potential of ferroptosis in tumorigenesis, cancer development and resistance to chemotherapy. However, the regulatory mechanism of ferroptosis remains unclear, which limits the application of ferroptosis in cancer treatment. Noncoding RNAs (ncRNAs) are noncoding transcripts that regulate gene expression in various ways to affect the malignant phenotypes of cancer cells. At present, the biological function and underlying regulatory mechanism of ncRNAs in cancer ferroptosis have been partially elucidated. Herein, we summarize the current knowledge of the central regulatory network of ferroptosis, with a focus on the regulatory functions of ncRNAs in cancer ferroptosis. The clinical application and prospects of ferroptosis-related ncRNAs in cancer diagnosis, prognosis and anticancer therapies are also discussed. Elucidating the function and mechanism of ncRNAs in ferroptosis, along with assessing the clinical significance of ferroptosis-related ncRNAs, provides new perspectives for understanding cancer biology and treatment approaches, which may benefit numerous cancer patients in the future.

MiRNAs in Lung Adenocarcinoma: Role, Diagnosis, Prognosis, and Therapy

Lung cancer has emerged as a significant public health challenge and remains the leading cause of cancer-related mortality worldwide. Among various types of lung malignancies, lung adenocarcinoma (LUAD) stands as the most prevalent form. MicroRNAs (miRNAs) play a crucial role in gene regulation, and their involvement in cancer has been extensively explored. While several reviews have been published on miRNAs and lung cancer, there remains a gap in the review regarding miRNAs specifically in LUAD. In this review, we not only highlight the potential diagnostic, prognostic, and therapeutic implications of miRNAs in LUAD, but also present an inclusive overview of the extensive research conducted on miRNAs in this particular context.

Emerging role of non-coding RNAs in resistance to platinum-based anti-cancer agents in lung cancer

Platinum-based drugs are the first line of therapeutics against many cancers, including lung cancer. Lung cancer is one of the leading causes of cancer-related death worldwide. Platinum-based agents target DNA and prevent replication, and transcription, leading to the inhibition of cell proliferation followed by cellular apoptosis. About twenty-three platinum-based drugs are under different stages of clinical trials, among cisplatin, carboplatin, and oxaliplatin are widely used for the treatment of various cancers. Among them, cisplatin is the most commonly used drug for cancer therapy, which binds with RNA, and hinders the cellular RNA process. However, long-term use of platinum-based drugs can cause different side effects and has been shown to develop chemoresistance, leading to poor clinical outcomes. Chemoresistance became an important challenge for cancer treatment. Platinum-based chemoresistance occurs due to the influence of intrinsic factors such as overexpression of multidrug resistance proteins, advancement of DNA repair mechanism, degradation, and deactivation of intracellular thiols. Recently, epigenetic modifications, especially non-coding RNAs (ncRNAs) mediated gene regulation, grasp the attention for reversing the sensitivity of platinum-based drugs due to their reversible nature without altering genome sequence. ncRNAs can also modulate the intrinsic and non-intrinsic mechanisms of resistance in lung cancer cells. Therefore, targeting ncRNAs could be an effective approach for developing novel therapeutics to overcome lung cancer chemoresistance. The current review article has discussed the role of ncRNA in chemoresistance and its underlying molecular mechanisms in human lung cancer.

The Importance of the Immune System and Molecular Cell Signaling Pathways in the Pathogenesis and Progression of Lung Cancer

Lung cancer is a disease that in recent years has become one of the greatest threats to modern society. Every year there are more and more new cases and the percentage of deaths caused by this type of cancer increases. Despite many studies, scientists are still looking for answers regarding the mechanisms of lung cancer development and progression, with particular emphasis on the role of the immune system. The aim of this literature review was to present the importance of disorders of the immune system and the accompanying changes at the level of cell signaling in the pathogenesis of lung cancer. The collected results showed that in the process of immunopathogenesis of almost all subtypes of lung cancer, changes in the tumor microenvironment, deregulation of immune checkpoints and abnormalities in cell signaling pathways are involved, which contribute to the multistage and multifaceted carcinogenesis of this type of cancer. We, therefore, suggest that in future studies, researchers should focus on a detailed analysis of tumor microenvironmental immune checkpoints, and to validate their validity, perform genetic polymorphism analyses in a wide range of patients and healthy individuals to determine the genetic susceptibility to lung cancer development. In addition, further research related to the analysis of the tumor microenvironment; immune system disorders, with a particular emphasis on immunological checkpoints and genetic differences may contribute to the development of new personalized therapies that improve the prognosis of patients.

Emerging role of miRNAs in the regulation of ferroptosis

Ferroptosis is a kind of cell death which has distinctive features differentiating it from autophagy, necrosis and apoptosis. This iron-dependent form of cell death is described by an increase in lipid reactive oxygen species, shrinkage of mitochondria and decrease in mitochondrial cristae. Ferroptosis is involved in the initiation and progression of many diseases and is regarded as a hotspot of investigations on treatment of disorders. Recent studies have shown that microRNAs partake in the regulation of ferroptosis. The impact of microRNAs on this process has been verified in different cancers as well as intervertebral disc degeneration, acute myocardial infarction, vascular disease, intracerebral hemorrhage, preeclampsia, hemorrhagic stroke, atrial fibrillation, pulmonary fibrosis and atherosclerosis. miR-675, miR-93, miR-27a, miR-34a and miR-141 have been shown to affect iron metabolism, antioxidant metabolism and lipid metabolism, thus influencing all pivotal mechanisms in the ferroptosis process. In the current review, we summarize the role of microRNAs in ferroptosis and their involvement in the pathetiology of malignant and non-malignant disorders.

MicroRNAs as Predictors of Lung-Cancer Resistance and Sensitivity to Cisplatin

Background: Platinum-based chemotherapy, cisplatin (DDP) specifically, is the main strategy for treating lung cancer (LC). However, currently, there is a lack of predictive drug-resistance markers, and there is increased interest in the development of a reliable and sensitive panels of markers for DDP chemotherapy-effectiveness prediction. MicroRNAs represent a perspective pool of markers for chemotherapy effectiveness. Objectives: Data on miRNAs associated with LC DDP chemotherapy response are summarized and analyzed. Materials and methods: A comprehensive review of the data in the literature and an analysis of bioinformatics resources were performed. The gene targets of miRNAs, as well as their reciprocal relationships with miRNAs, were studied using several databases. Results and Discussion: The complex analysis of bioinformatics resources and the literature indicated that the expressions of 12 miRNAs have a high predictive potential for LC DDP chemotherapy responses. The obtained information was discussed from the point of view of the main mechanisms of LC chemoresistance. Conclusions: An overview of the published data and bioinformatics resources, with respect to the predictive microRNA markers of chemotherapy response, is presented in this review. The selected microRNAs and gene panel have a high potential for predicting LC DDP sensitiveness or DDP resistance as well as for the development of a DDP co-therapy.

Let-7c-5p Restrains Cell Growth and Induces Apoptosis of Lung Adenocarcinoma Cells via Targeting ESPL1

Lung adenocarcinoma (LUAD) is a predominant malignancy, and its high mortality prompts us to incessantly probe the relevant targeted treatment. This work intended to study the molecular mechanism of ESPL1 in LUAD. Bioinformatics analysis was performed for pan-cancer and prognosis analysis as well as target gene prediction. Expression of ESPL1 mRNA and let-7c-5p was determined via qRT-PCR, and western blot was employed to detect protein level of ESPL1. Dual-luciferase reporter gene method verified the interaction between ESPL1 and let-7c-5p. Thereafter, CCK-8, wound healing, Transwell, and flow cytometry assays were utilized to investigate proliferation, migration, and apoptosis of LUAD cells. The results revealed that ESPL1 was upregulated in LUAD, which was associated with poor prognosis. Overexpressed ESPL1 promoted LUAD cells to invade, proliferate, and migrate. Furthermore, ESPL1 was a target gene of let-7c-5p. Let-7c-5p was downregulated in LUAD cells, and played a suppressive role in LUAD malignant development, while reversed by ESPL1. Taken together, it was posited that let-7c-5p/ESPL1 may be underlying therapeutic targets of LUAD.

circ_0020123 promotes cell proliferation and migration in lung adenocarcinoma via PDZD8

High circ_0020123 expression is associated with poor prognosis in patients with non-small cell lung cancer (NSCLC) as previously reported. Whether circ_0020123 also plays an oncogenic role in lung adenocarcinoma (LUAD) is still unknown. Additionally, circ_0020123 is derived from part of exon (1312–3851) from its host gene PDZ domain-containing protein 8 (PDZD8). We hypothesized that circ_0020123 might affect malignant behaviors of LUAD cells by regulating PDZD8. Reverse transcription quantitative polymerase chain reaction revealed that PDZD8 was highly expressed in LUAD tissues and cells. PDZD8 knockdown suppressed LUAD cell proliferation and migration as shown by colony formation assays, Ethynyl deoxyuridine incorporation assays, Transwell assays, and wound healing assays. circ_0020123 was also found to be upregulated in LUAD tissues and cells. Moreover, circ_0020123 positively regulated PDZD8 expression in LUAD cells but exerted no significant effect on the transcriptional level of PDZD8. Mechanistically, circ_0020123 act as a competing endogenous RNA (ceRNA) to interact with miR-1283, thereby releasing the repression on PDZD8. Moreover, PDZD8 overexpression rescued the suppressive effect of circ_0020123 knockdown on LUAD cell proliferation and migration. In conclusion, circ_0020123 interacts with miR-1283 as a ceRNA to regulate PDZD8 expression, thus promoting the proliferation and migration of LUAD cells. The study might provide new biomarkers for future LUAD investigation.

The Roles of microRNAs in Cancer Multidrug Resistance

Simple Summary

The resistance of neoplastic cells to multiple drugs is a serious problem in cancer chemotherapy. The molecular causes of multidrug resistance in cancer are largely known, but less is known about the mechanisms by which cells deliver phenotypic changes that resist the attack of anticancer drugs. The findings of RNA interference based on microRNAs represented a breakthrough in biology and pointed to the possibility of sensitive and targeted regulation of gene expression at the post-transcriptional level. Such regulation is also involved in the development of multidrug resistance in cancer. The aim of the current paper is to summarize the available knowledge on the role of microRNAs in resistance to multiple cancer drugs.

Abstract

Cancer chemotherapy may induce a multidrug resistance (MDR) phenotype. The development of MDR is based on various molecular causes, of which the following are very common: induction of ABC transporter expression; induction/activation of drug-metabolizing enzymes; alteration of the expression/function of apoptosis-related proteins; changes in cell cycle checkpoints; elevated DNA repair mechanisms. Although these mechanisms of MDR are well described, information on their molecular interaction in overall multidrug resistance is still lacking. MicroRNA (miRNA) expression and subsequent RNA interference are candidates that could be important players in the interplay of MDR mechanisms. The regulation of post-transcriptional processes in the proteosynthetic pathway is considered to be a major function of miRNAs. Due to their complementarity, they are able to bind to target mRNAs, which prevents the mRNAs from interacting effectively with the ribosome, and subsequent degradation of the mRNAs can occur. The aim of this paper is to provide an overview of the possible role of miRNAs in the molecular mechanisms that lead to MDR. The possibility of considering miRNAs as either specific effectors or interesting targets for cancer therapy is also analyzed.

MicroRNAs involved in drug resistance of breast cancer by regulating autophagy

Autophagy is a conserved catabolic process characterized by degradation and recycling of cytosolic components or organelles through a lysosome-dependent pathway. It has a complex and close relationship to drug resistance in breast cancer. MicroRNAs (miRNAs) are small noncoding molecules that can influence numerous cellular processes including autophagy, through the posttranscriptional regulation of gene expression. Autophagy is regulated by many proteins and pathways, some of which in turn have been found to be regulated by miRNAs. These miRNAs may affect the drug resistance of breast cancer. Drug resistance is the main cause of distant recurrence, metastasis and death in breast cancer patients. In this review, we summarize the causative relationship between autophagy and drug resistance of breast cancer. The roles of autophagy-related proteins and pathways and their associated miRNAs in drug resistance of breast cancer are also discussed.

Knockdown of circBFAR inhibits proliferation and glycolysis in gastric cancer by sponging miR-513a-3p/hexokinase 2 axis

The relationship between circular RNAs (circRNAs) and many types of cancer has been of great interest. A novel circRNA, circBFAR, has been identified, but the functions of circBFAR and its underlying mechanism in gastric cancer (GC) have not been reported. This study was designed to investigate the role of circBFAR in GC and its downstream miRNA targets. Quantitative real-time polymerase reaction was used to detect the expression of circBFAR and miRNAs. Cell counting kit-8 and EdU were used to detect the proliferation of GC cells. Measurement of the extracellular acidification rate, oxygen consumption rate and lactate acid production were performed to assess the glycolysis levels. The results showed that circBFAR exhibited higher expression in GC tissues and cell lines. circBFAR was proven to promote GC proliferation by targeting the miR-513a-3p/hexokinase 2 (HK2) axis. Inhibition of circBFAR also led to a significant decrease in the glycolysis levels. In this study, we found a circBFAR/miR-513a-3p/HK2 axis in GC and revealed the relationship between circBFAR and glycolysis for the first time. circBFAR may serve as a novel target of GC individualized therapy.

miRNA Regulation of Glutathione Homeostasis in Cancer Initiation, Progression and Therapy Resistance

Glutathione (GSH) is the most abundant antioxidant that contributes to regulating the cellular production of Reactive Oxygen Species (ROS) which, maintained at physiological levels, can exert a function of second messengers in living organisms. In fact, it has been demonstrated that moderate amounts of ROS can activate the signaling pathways involved in cell growth and proliferation, while high levels of ROS induce DNA damage leading to cancer development. Therefore, GSH is a crucial player in the maintenance of redox homeostasis and its metabolism has a role in tumor initiation, progression, and therapy resistance. Our recent studies demonstrated that neuroblastoma cells resistant to etoposide, a common chemotherapeutic drug, show a partial monoallelic deletion of the locus coding for miRNA 15a and 16-1 leading to a loss of these miRNAs and the activation of GSH-dependent responses. Therefore, the aim of this review is to highlight the role of specific miRNAs in the modulation of intracellular GSH levels in order to take into consideration the use of modulators of miRNA expression as a useful strategy to better sensitize tumors to current therapies.

Exosomes Derived From Macrophages Enhance Aerobic Glycolysis and Chemoresistance in Lung Cancer by Stabilizing c-Myc via the Inhibition of NEDD4L

As one of the most common and lethal cancer, lung cancer severely threatens the health of human. It has been reported that tumor-associated macrophages promote initiation, progression, as well as chemoresistance in human cancers. However, the underneath molecular mechanism that drives chemoresistance in lung cancer is yet not fully characterized. In this article, we demonstrated that M2 macrophage-derived exosomes (MDE) is the key factor to promote cisplatin-resistance in lung cancer. MDE exhibited high expression level of several miRNA including miR-3679-5p. Mechanistically, miR-3679-5p was delivered to lung cancer cells by MDE, downregulating the expression of a known E3 ligase, NEDD4L, which has been identified as a key regulator controlling the stability of c-Myc. Such decreased NEDD4L expression level resulted in the stabilization of c-Myc and elevated glycolysis. The enhanced glycolysis drives the chemoresistance in lung cancer. Taken together, our findings not only show that M2 macrophage induce chemoresistance in lung cancer through MDE mediated miR-3679-5R/NEDD4L/c-Myc signaling cascade, but also shed the light on the mechanism of the cross-talk between M2 macrophage and lung cancers. By pinpointing a potential novel survival signaling pathway, our data could provide a new potential therapeutic target for lung cancer treatment and management.

Lung cancer cells and their sensitivity/resistance to cisplatin chemotherapy: Role of microRNAs and upstream mediators

Cisplatin (CP) is a well-known chemotherapeutic agent with excellent clinical effects. The anti-tumor activity of CP has been demonstrated in different cancers such as breast, cervical, reproductive, lung, brain, and prostate cancers. However, resistance of cancer cells to CP chemotherapy has led to its failure in eradication of cancer cells, and subsequent death of patients with cancer. Fortunately, much effort has been put to identify molecular pathways and mechanisms involved in CP resistance/sensitivity. It seems that microRNAs (miRs) are promising candidates in mediating CP resistance/sensitivity, since they participate in different biological aspects of cells such as proliferation, migration, angiogenesis, and differentiation. In this review, we focus on miRs and their regulation in CP chemotherapy of lung cancer, as the most malignant tumor worldwide. Oncogenic miRs trigger CP resistance in lung cancer cells via targeting various pathways such as Wnt/β-catenin, Rab6, CASP2, PTEN, and Apaf-1. In contrast, onco-suppressor miRs inhibit oncogene pathways such as STAT3 to suppress CP resistance. These topics are discussed to determine the role of miRs in CP resistance/sensitivity. We also describe the upstream modulators of miRs such as lncRNAs, circRNAs, NF-κB, SOX2 and TRIM65 and their association with CP resistance/sensitivity in lung cancer cells. Finally, the effect of anti-tumor plant-derived natural compounds on miR expression during CP sensitivity of lung cancer cells is discussed.

LncRNA UCA1 Enhances Cisplatin Resistance by Regulating CYP1B1-mediated Apoptosis via miR-513a-3p in Human Gastric Cancer

Background

Chemoresistance contributes to treatment failure of gastric cancer (GC) patients but the molecular mechanism of chemoresistance in GC is still unclear. Long-chain noncoding RNA (lncRNA) urothelial cancer associated 1 (UCA1) is associated with resistance to chemotherapy drugs.

Methods

We detected the expression of UCA1 in 53 pairs of GC tumor tissue and adjacent normal tissue, human normal gastric mucosa cells (GES-1) and human GC cells (HGC-27, SNU-5, AGS, SGC-7901, and NCI-N87) using RT-qPCR. Small RNA interference technology was used to knock down the expression of UCA1 in gastric cancer cells. CCK8 solution was used to detect cell viability. Flow cytometry was used to detect apoptosis, and Western blotting was used to detect protein expression.

Results

UCA1 was highly expressed in GC tissues and cells, and knockdown of UCA1 increased chemosensitivity to cisplatin by inducing cell apoptosis. Furthermore, UCA1 promoted CYP1B1 expression by binding to miR-513a-3p in human GC cells in vitro, and UCA1/CYP1B1 expression was negatively related to miR-513a-3p expression, while UCA1 expression was positively related to CYP1B1 expression in human GC tissues. Moreover, overexpression of miR-513a-3p or knockdown of CYP1B1 increased chemosensitivity to cisplatin, and knockdown of miR-513a-3p or overexpression of CYP1B1 decreased chemosensitivity to cisplatin by inducing cell apoptosis in human GC cells. Importantly, overexpression of CYP1B1 reduced chemosensitivity to cisplatin which increased by knockdown of UCA1, and knockdown of CYP1B1 increased chemosensitivity to cisplatin which decreased by knockdown of miR-513a-3p in human GC cells.

Conclusion

The lncRNA UCA1/miR-513a-3p/CYP1B1 axis regulates cisplatin resistance in human GC cells; hence, it is a potential target for treating chemoresistance in GC.

MicroRNAs: Emerging oncogenic and tumor-suppressive regulators, biomarkers and therapeutic targets in lung cancer

Lung cancer is one of the most common solid tumors worldwide and the leading cause of cancer-related deaths, causing a devastating impact on human health. The clinical prognosis of lung cancer is usually restricted by delayed diagnosis and resistance to anticancer therapies. MicroRNAs, a range of small endogenous noncoding RNAs 22 nucleotides in length, have emerged as one of the most important players in cancer initiation and progression in recent decades. Current evidence reveals pivotal roles of microRNAs in regulating cell proliferation, migration, invasion and metastasis in lung cancer. An increasing number of preclinical and clinical studies have also explored the potential of microRNAs as promising biomarkers and new therapeutic targets for lung cancer. The current review summarizes the most recent progress on the functional mechanisms of microRNAs involved in lung cancer development and progression and further discusses the clinical application of miRNAs as putative therapeutic targets for molecular diagnosis and prognostic prediction in lung cancer.

Flavonoid display ability to target microRNAs in cancer pathogenesis

MicroRNAs (miRNAs) are non-coding, conserved, single-stranded nucleotide sequences involved in physiological and developmental processes. Recent evidence suggests an association between miRNAs' deregulation with initiation, promotion, progression, and drug resistance in cancer cells. Besides, miRNAs are known to regulate the epithelial-mesenchymal transition, angiogenesis, autophagy, and senescence in different cancer types. Previous reports proposed that apart from the antioxidant potential, flavonoids play an essential role in miRNAs modulation associated with changes in cancer-related proteins, tumor suppressor genes, and oncogenes. Thus, flavonoids can suppress proliferation, help in the development of drug sensitivity, suppress metastasis and angiogenesis by modulating miRNAs expression. In the present review, we summarize the role of miRNAs in cancer, drug resistance, and the chemopreventive potential of flavonoids mediated by miRNAs. The potential of flavonoids to modulate miRNAs expression in different cancer types demonstrate their selectivity and importance as regulators of carcinogenesis. Flavonoids as chemopreventive agents targeting miRNAs are extensively studied in vitro, in vivo, and pre-clinical studies, but their efficiency in targeting miRNAs in clinical studies is less investigated. The evidence presented in this review highlights the potential of flavonoids in cancer prevention/treatment by regulating miRNAs, although further investigations are required to validate and establish their clinical usefulness.

Silencing of long non-coding RNA LINC01270 inhibits esophageal cancer progression and enhances chemosensitivity to 5-fluorouracil by mediating GSTP1methylation

Esophageal cancer (EC) is a serious digestive malignancy which remains the sixth leading cause of cancer-related deaths worldwide. Emerging evidence suggests the involvement of long non-coding RNAs (lncRNAs) in the tumorigenesis of EC and thus, in this study we explored the potential effects of lncRNA LINC01270 on EC cell proliferation, migration, invasion and, drug resistance via regulation of glutathione S-transferase P1 (GSTP1) methylation. First, we screened out the EC-related differentially expressed lncRNAs, and the expression of our top candidate LINC01270 was quantified in EC tissues and cells. To define the role of LINC01270 in EC progression, we evaluated the proliferation, migration and invasion of EC cells when the LINC01270 was overexpressed or knocked down, in the presence of the GSTP1 methylation inhibitor SGI-1027 and 5-fluorouracil (5-FU). In addition, interaction between LINC01270 and methylation of the GSTP1 promoter was identified. Finally, we assessed transplantable tumor growth in nude mice. LINC01270 was up-regulated and GSTP1 was down-regulated in EC tissues and cells. Silencing of LINC01270 inhibited migration and invasion, and enhanced the sensitivity of 5-FU in EC cells. We found that LINC01270 recruited the DNA methyltransferases DNMT1, DNMT3A and DNMT3B initiating GSTP1 promoter methylation, thereby leading to the proliferation, migration, invasion and drug resistance of EC cells. Moreover, GSTP1 overexpression was observed to reverse the effects of LINC01270 overexpression on EC cells and their response to 5-FU. Taken together, this study shows that inhibition of LINC01270 can lead to suppression of EC progression via demethylation of GSTP1, highlighting this lncRNA as a potential target for EC treatment.

Knockdown of LINC00473 promotes radiosensitivity of non-small cell lung cancer cells via sponging miR-513a-3p

Non-small cell lung cancer (NSCLC) is the most common form of lung cancer. Radioresistance is a significant obstacle in NSCLC radiotherapy. Long non-coding RNA LINC00473 has been found to impact the radiotherapy in several malignant tumours. This study aimed to investigate the underlying role and mechanism of LINC00473 in regulating radiosensitivity of NSCLC cells. The levels of LINC00473 and miR-513a-3p were measured by quantitative Real-Time PCR. The relationship of LINC00473 with overall survival was tested by the Kaplan-Meier method. The effects of LINC00473 on cell viability and cell survival were assessed by cell counting kit-8 (CCK-8) and colony survival assay in NSCLC cells exposed to different doses of radiation. A luciferase reporter assay was used to investigate the correlation between LINC00473 and miR-513a-3p. The present study showed that the relative LINC00473 expression was upregulated and miR-513a-3p expression was downregulated in radioresistant NSCLC patients compared with radiosensitive patients. And upregulated LINC00473 expression was associated with poor prognosis of NSCLC patients after radiotherapy. Radiation led to an increase in LINC00473 expression in a dose- and time-dependent manner. The knockdown of LINC00473 markedly promoted radiosensitivity in NSCLC cells under different doses of radiation. LINC00473 was a sponge of miR-513a-3p and negatively regulated the miR-513a-3p expression. In conclusion, the inhibition of miR-513a-3p markedly reversed the promoted effect of LINC00473 knockdown on cell radiosensitivity. LINC00473 inhibition enhances radiosensitivity of NSCLC by sponging miR-513a-3p, providing a promising therapeutic target to increase the sensitivity of radiotherapy in NSCLC patients.

Crosstalk between noncoding RNAs and ferroptosis: new dawn for overcoming cancer progression

Cancer progression including proliferation, metastasis, and chemoresistance has become a serious hindrance to cancer therapy. This phenomenon mainly derives from the innate insensitive or acquired resistance of cancer cells to apoptosis. Ferroptosis is a newly discovered mechanism of programmed cell death characterized by peroxidation of the lipid membrane induced by reactive oxygen species. Ferroptosis has been confirmed to eliminate cancer cells in an apoptosis-independent manner, however, the specific regulatory mechanism of ferroptosis is still unknown. The use of ferroptosis for overcoming cancer progression is limited. Noncoding RNAs have been found to play an important roles in cancer. They regulate gene expression to affect biological processes of cancer cells such as proliferation, cell cycle, and cell death. Thus far, the functions of ncRNAs in ferroptosis of cancer cells have been examined, and the specific mechanisms by which noncoding RNAs regulate ferroptosis have been partially discovered. However, there is no summary of ferroptosis associated noncoding RNAs and their functions in different cancer types. In this review, we discuss the roles of ferroptosis-associated noncoding RNAs in detail. Moreover, future work regarding the interaction between noncoding RNAs and ferroptosis is proposed, the possible obstacles are predicted and associated solutions are put forward. This review will deepen our understanding of the relationship between noncoding RNAs and ferroptosis, and provide new insights in targeting noncoding RNAs in ferroptosis associated therapeutic strategies.

Circular RNA MYLK promotes tumour growth and metastasis via modulating miR-513a-5p/VEGFC signalling in renal cell carcinoma

Growing evidence indicates that circular RNAs (circRNAs) are promising biomarkers, as they play significant roles in the development of various cancers. The circular RNA MYLK (circMYLK) has been reported to be involved in the development of malignant tumours, including liver, prostate and bladder cancers. Nevertheless, the biological function of circMYLK in renal cell carcinoma (RCC) remains unclear. In this study, we observed that circMYLK is notably up-regulated in RCC. Increased circMYLK expression led to a larger tumour size, distant metastasis and poor prognosis of RCC patients. Moreover, circMYLK silencing repressed RCC growth and metastasis in vitro and in vivo. Mechanistically, circMYLK can capture miR-513a-5p to facilitate VEGFC expression and further promote the tumorigenesis of RCC cells. In summary, our findings demonstrate that circMYLK has an oncogenic role in RCC growth and metastasis by modulating miR-513a-5p/VEGFC signalling. Thus, circMYLK has potential as a diagnostic biomarker and therapeutic target in the treatment of RCC.

MicroRNA-513a-3p regulates colorectal cancer cell metabolism via targeting hexokinase 2

Disruption of cell metabolism is a hallmark of cancer cells. Accumulating evidence suggests that microRNAs (miRNAs/miRs) are involved in almost all physiological and pathological processes. The aberrant expression of miRNAs induces metabolic reprogramming in cancer cells and thus, promotes proliferation. In the current study, miR-513a-3p was identified as a significantly downregulated miRNA in colorectal cancer cells and tumors. Overexpression of miR-513a-3p in colorectal cancer cells inhibited proliferation and glycolysis. A well-documented metabolic regulator, hexokinase 2 (HK2), was predicted and validated HK2to be a target gene of miR-513a-3p in colorectal cancer cells. In addition, overexpression of HK2 reversed the miR-513a-3p mimic-induced inhibition of proliferation. The association between HK2 and miR-513a-3p was further observed in tumors collected from patients with colorectal cancer. The findings suggest that miR-513a-5p may inhibit glycolysis in colorectal cancer cells via repressing HK2 expression, indicating that miR-513a-5p may be a tumor suppressor in colorectal cancer.

GSTP1 and cancer: Expression, methylation, polymorphisms and signaling (Review)

Glutathione S‑transferase Pi (GSTP1) is an isozyme encoded by the GST pi gene that plays an important regulatory role in detoxification, anti‑oxidative damage, and the occurrence of various diseases. The aim of the present study was to review the association between the expression of GSTP1 and the development and treatment of various cancers, and discuss GSTP1 methylation in several malignant tumors, such as prostate, breast and lung cancer, as well as hepatocellular carcinoma; to review the association between polymorphism of the GSTP1 gene and various diseases; and to review the effects of GSTP1 on electrophilic oxidative stress, cell signal transduction, and the regulation of carcinogenic factors. Collectively, GSTP1 plays a major role in the development of various diseases.

MiR-27b suppresses epithelial-mesenchymal transition and chemoresistance in lung cancer by targeting Snail1

HEADING AIMS

MicroRNA-27b (miR-27b) has been shown to play a role in the progression of many different forms of cancer, but its specific relevance in the context of non-small cell lung cancer (NSCLC) remains uncertain. As such, this study sought to explore the role of miR-27b in NSCLC and the mechanisms whereby it functions.

MATERIALS AND METHODS

We quantified miR-27b and target gene expression via quantitative real-time PCR (RT-qPCR).We then used functional including proliferation assays, migration assay, flow cytometry, and western blotting to explore the mechanisms whereby miR-27b functions in vitro and in vivo. We additionally confirmed miR-27b target genes via luciferase reporter assay.

KEY FINDINGS

We observed a marked decrease in miR-27b expression in NSCLC patient samples relative to paracancerous control tissues. We further found that altering miR-27b expression levels in vitro affected NSCLC tumor cell migration, proliferation, and ability to undergo epithelial-mesenchymal transition. Through the use of target prediction algorithms we identified Snail to be a miR-27b target protein that was suppressed when this miRNA was highlight expressed. Lastly, we found miR-27b expression to increase NSCLC cell sensitivity to cisplatin through its ability to target Snail.

SIGNIFICANCE

Our results clearly demonstrate that miR-27b can suppress NSCLC tumor development and progression, highlighting this miR-27b/Snail1 axis as putative target for the therapeutic treatment of NSCLC.

Cisplatin decreases cyclin D2 expression via upregulating miR‑93 to inhibit lung adenocarcinoma cell growth

MicroRNAs (miRNAs/miRs) serve important roles in the chemotherapeutic effect of anticancer drugs. To investigate the roles of miRNAs in cisplatin‑induced suppression of lung adenocarcinoma cell proliferation, A549 cells were treated with different concentrations of cisplatin. An MTT assay demonstrated that cisplatin inhibited A549 cell proliferation in a dose‑dependent manner. Cisplatin induced cell apoptosis and inhibited cell migration by increasing the levels of miR‑93, miR‑26a and miR‑26b. Furthermore, as an upstream factor, miR‑93 was proposed to regulate cyclin D2 expression in miR‑93‑transfected A549 cells. Cisplatin also induced Bcl‑2‑associated X protein expression, and decreased that of Bcl‑2 and c‑Myc in lung adenocarcinoma cells. In vivo analysis further supported that cisplatin inhibited lung adenocarcinoma cell growth by regulating cyclin D2 and miR‑93 expression. In conclusion, our findings demonstrated that cisplatin could effectively inhibit lung adenocarcinoma cell proliferation by decreasing cyclin D2 expression via miR‑93.

The role and mechanisms of action of microRNAs in cancer drug resistance

MicroRNAs (miRNAs) are small non-coding RNAs with a length of about 19–25 nt, which can regulate various target genes and are thus involved in the regulation of a variety of biological and pathological processes, including the formation and development of cancer. Drug resistance in cancer chemotherapy is one of the main obstacles to curing this malignant disease. Statistical data indicate that over 90% of the mortality of patients with cancer is related to drug resistance. Drug resistance of cancer chemotherapy can be caused by many mechanisms, such as decreased antitumor drug uptake, modified drug targets, altered cell cycle checkpoints, or increased DNA damage repair, among others. In recent years, many studies have shown that miRNAs are involved in the drug resistance of tumor cells by targeting drug-resistance-related genes or influencing genes related to cell proliferation, cell cycle, and apoptosis. A single miRNA often targets a number of genes, and its regulatory effect is tissue-specific. In this review, we emphasize the miRNAs that are involved in the regulation of drug resistance among different cancers and probe the mechanisms of the deregulated expression of miRNAs. The molecular targets of miRNAs and their underlying signaling pathways are also explored comprehensively. A holistic understanding of the functions of miRNAs in drug resistance will help us develop better strategies to regulate them efficiently and will finally pave the way toward better translation of miRNAs into clinics, developing them into a promising approach in cancer therapy.

Through oxaliplatin resistance induction in colorectal cancer cells, increasing ABCB1 level accompanies decreasing level of miR-302c-5p, miR-3664-5p and miR-129-5p

Oxaliplatin as a component of (Neo-) adjuvant chemotherapeutic regimens is administered to colorectal cancer patients. Unfortunately, the acquisition of resistance to this drug in nearly 90% of metastatic patients rendered it as an ineffective drug. Therefore, resistance mechanisms to this drug should be elucidated. There are different genes like GSTP1 and ABCB1 which are responsible for oxaliplatin resistance. We hypothesized that miR-129-5p, miR-302c-5p, miR-3664-5p, mir-3714 and miR-513a-3p are targeting ABCB1 gene, while GSTP1 was predicted to be the potential target of miR-3664-5p, mir-3714 and miR-513a-3p. In order to study this hypothesis, resistant colorectal cell lines were generated through intermittent exposure of HCT116, SW480 and HT29 to the increasing doses of oxaliplatin. MTT assays validated this resistance induction. Expression of ABCB1 and GSTP1 in addition to their targeting miRNAs in different cell lines were studied by quantitative real time PCR in the cell lines. Even though in comparison with HCT116 and SW480 cell lines, GSTP1 expression was reduced in resistant cells, ABCB1 expression was upregulated in these cell lines. On the other hand, HT-29 resistant cells showed elevated GSTP1 and unchanged ABCB1 levels. While miR-302c-5p level was downregulated in resistant cell lines, miR-129-5p and miR-3664-5p level showed different pattern of reduction in the resistant SW480 and HCT116 cell lines. GSTP1 level was correlated directly with miR-513a-3p and miR-3664-5p in all SW480 and HCT116 derived cell lines, however in HT-29-OXR1, GSTP1 level was correlated inversely with miR-3664-5p. In conclusion, upregulation of ABCB1 can be considered as the crucial component of poor response to oxaliplatin which is likely controlled by miR-302c-5p.

The multifaceted role of glutathione S-transferases in cancer

Glutathione S-transferases (GSTs) are phase II detoxifying enzymes involved in the maintenance of cell integrity, oxidative stress and protection against DNA damage by catalyzing the conjugation of glutathione to a wide variety of electrophilic substrates. Though enzymes of the glutathione synthesis and salvage pathways have been well characterized in the past, there is still a lack of comprehensive understanding of their independent and coordinate regulatory mechanisms in carcinogenesis. The present review discusses implication of GST in cancer development and progression, gene polymorphism, drug resistance, signaling and epigenetic regulation involving their role in cancer. It is anticipated that GST especially the GSTP1 class can be developed as a biomarker either used alone or in combination with other biomarkers for early cancer detection and/or diagnosis as well as for future targeted preventive and therapeutic interventions with dietary agents.

Rifampin modulation of xeno- and endobiotic conjugating enzyme mRNA expression and associated microRNAs in human hepatocytes

Rifampin is a pleiotropic inducer of multiple drug metabolizing enzymes and transporters. This work utilized a global approach to evaluate rifampin effects on conjugating enzyme gene expression with relevance to human xeno‐ and endo‐biotic metabolism. Primary human hepatocytes from 7 subjects were treated with rifampin (10 μmol/L, 24 hours). Standard methods for RNA‐seq library construction, EZBead preparation, and NextGen sequencing were used to measure UDP‐glucuronosyl transferase UGT, sulfonyltransferase SULT, N acetyltransferase NAT, and glutathione‐S‐transferase GST mRNA expression compared to vehicle control (0.01% MeOH). Rifampin‐induced (>1.25‐fold) mRNA expression of 13 clinically important phase II drug metabolizing genes and repressed (>1.25‐fold) the expression of 3 genes (P < .05). Rifampin‐induced miRNA expression changes correlated with mRNA changes and miRNAs were identified that may modulate conjugating enzyme expression. NAT2 gene expression was most strongly repressed (1.3‐fold) by rifampin while UGT1A4 and UGT1A1 genes were most strongly induced (7.9‐ and 4.8‐fold, respectively). Physiologically based pharmacokinetic modeling (PBPK) was used to simulate the clinical consequences of rifampin induction of CYP3A4‐ and UGT1A4‐mediated midazolam metabolism. Simulations evaluating isolated UGT1A4 induction predicted increased midazolam N‐glucuronide exposure (~4‐fold) with minimal reductions in parent midazolam exposure (~10%). Simulations accounting for simultaneous induction of both CYP3A4 and UGT1A4 predicted a ~10‐fold decrease in parent midazolam exposure with only a ~2‐fold decrease in midazolam N‐glucuronide metabolite exposure. These data reveal differential effects of rifampin on the human conjugating enzyme transcriptome and potential associations with miRNAs that form the basis for future mechanistic studies to elucidate the interplay of conjugating enzyme regulatory elements.

miR-339-5p inhibits metastasis of non-small cell lung cancer by regulating the epithelial-to-mesenchymal transition

Metastasis is a common event in cancer pathology, and represents the primary cause of cancer-associated mortality. Metastasis, which is the process in which cancer cells at the primary tumor site spread to a different location in the body and form a new tumor, is regulated by multiple factors and includes a number of steps and stages. In our previous study, it was demonstrated miR-339-5p inhibits cell migration and invasion in vitro and is associated with the tumor-node-metastasis stage and the lymph node metastasis status of non-small cell lung cancer. In the present study, expression of miR-339-5p was first determined in the tissues and peripheral blood of patients with non-small cell lung cancer (NSCLC) and in NSCLC cell lines. It was then demonstrated that miR-339-5p inhibits A549 and H1299 cell invasion. The underlying molecular events of miR-339-5p action in NSCLC were also explored. By luciferase assay and western blot analysis, B-cell CLL/lymphoma 6 (BCL6) was verified as the direct target gene of miR-339-5p. miR-339-5p may inhibit lung cancer cell invasion and migration by regulating the epithelial-to-mesenchymal transition via BCL6 in vitro. It was also demonstrated that the relative expression of miR-339-5p in the peripheral blood is associated with cancer metastasis in patients with non-small cell lung cancer.

MicroRNAs as regulators of cisplatin-resistance in non-small cell lung carcinomas

With more than 80% of all diagnosed lung cancer cases, non-small cell lung cancer (NSCLC) remains the leading cause of cancer death worldwide. Exact diagnosis is mostly very late and advanced-stage NSCLCs are inoperable at admission. Tailored therapies with tyrosine kinase inhibitors are only available for a minority of patients. Thus, chemotherapy is often the treatment of choice. As first-line chemotherapy for NSCLCs, platinum-based substances (e.g. cisplatin, CDDP) are mainly used. Unfortunately, the positive effects of CDDP are frequently diminished due to development of drug resistance and negative influence of microenvironmental factors like hypoxia. MicroRNAs (miRNAs) are small, non-coding molecules involved in the regulation of gene expression and modification of biological processes like cell proliferation, apoptosis and cell response to chemotherapeutics. Expression of miRNAs is often deregulated in lung cancer compared to corresponding non-malignant tissue. In this review we summarize the present knowledge about the effects of miRNAs on CDDP-resistance in NSCLCs. Further, we focus on miRNAs deregulated by hypoxia, which is an important factor in the development of CDDP-resistance in NSCLCs. This review will contribute to the general understanding of miRNA-regulated biological processes in NSCLC, with special focus on the role of miRNA in CDDP-resistance.

miR-206 regulates cisplatin resistance and EMT in human lung adenocarcinoma cells partly by targeting MET

MicroRNAs (miRNAs) play a critical role in drug resistance and epithelial-mesenchymal transition (EMT). The aims of this study were to explore the potential role of miR-206 in governing cisplatin resistance and EMT in lung cancer cells. We found that both lung adenocarcinoma A549 cisplatin-resistant cells (A549/DDP) and H1299 cisplatin-resistant cells (H1299/DDP) acquired mesenchymal features and were along with low expression of miR-206 and high migration and invasion abilities. Ectopic expression of miR-206 mimics inhibited cisplatin resistance, reversed the EMT phenotype, decreased the migration and invasion in these DDP-resistant cells. In contrast, miR-206 inhibitors increased cisplatin resistance, EMT, cell migration and invasion in non-DDP-resistant cells. Furthermore, we found that MET is the direct target of miR-206 in lung cancer cells. Knockdown of MET exhibited an EMT and DDP resistant inhibitory effect on DDP-resistant cells. Conversely, overexpression of MET in non-DDP- resistant cells produced a promoting effect on cell EMT and DDP resistance. In lung adenocarcinoma tissues, we demonstrated that low expression of miR-206 were also correlated with increased cisplatin resistance and MET expression. In addition, we revealed that miR-206 overexpression reduced cisplatin resistance and EMT in DDP-resistant cells, partly due to inactivation of MET/PI3K/AKT/mTOR signaling pathway, and subsequent downregulation of MDR1, ZEB1 and Snail expression. Finally, we found that miR-206 could also sensitize A549/DDP cells to cisplatin in mice model. Taken together, our study implied that activation of miR-206 or inactivation of its target gene pathway could serve as a novel approach to reverse cisplatin resistance in lung adenocarcinomas cells.

Differential expression and miRNA regulation of the GSTP1 gene in the regenerating liver of Chiloscyllium plagiosum

Liver regeneration is a complicated process, and understanding the regulatory mechanism will be helpful in the treatment of diseases associated with liver. In this study, the one-third liver resection model was established in Chiloscyllium plagiosum, and the whole transcriptome of the C. plagiosum was generated using the Illumina-Solexa sequencing platform. Differentially expressed genes were analyzed using bioinformatics methods and verified using quantitative real-time PCR (qRT-PCR). Using miRanda and TargetScan, we screened the microRNA library for miRNAs that target the glutathione S-transferase P1(GSTP1) gene. Dual-luciferase reporter assays were used to confirm binding between the miRNA and GSTP1. Finally, we used western blotting analysis to determine expression of the GSTP1 protein. As a result, 65,356 unigenes were obtained in normal and damaged liver tissues, with mean length of 955 bp. A total of 359 differentially expressed genes were acquired; 217 of which were upregulated, and 142 were downregulated, including the GSTP1 gene, following liver resection. The presence of the GSTP1 protein in C. plagiosum was shown for the first time. Luciferase reporter assay revealed that GSTP1 messenger RNA was targeted by ipu-miR-143. The discovery and differential expression analysis of GSTP1 in C. plagiosum will be a valuable resource to explain the molecular mechanism of GSTP1 regulation of liver repair.

Regulation of multidrug resistance by microRNAs in anti-cancer therapy

Multidrug resistance (MDR) remains a major clinical obstacle to successful cancer treatment. Although diverse mechanisms of MDR have been well elucidated, such as dysregulation of drugs transporters, defects of apoptosis and autophagy machinery, alterations of drug metabolism and drug targets, disrupti on of redox homeostasis, the exact mechanisms of MDR in a specific cancer patient and the cross-talk among these different mechanisms and how they are regulated are poorly understood. MicroRNAs (miRNAs) are a new class of small noncoding RNAs that could control the global activity of the cell by post-transcriptionally regulating a large variety of target genes and proteins expression. Accumulating evidence shows that miRNAs play a key regulatory role in MDR through modulating various drug resistant mechanisms mentioned above, thereby holding much promise for developing novel and more effective individualized therapies for cancer treatment. This review summarizes the various MDR mechanisms and mainly focuses on the role of miRNAs in regulating MDR in cancer treatment.

MicroRNAs as key mediators of hepatic detoxification

MicroRNAs (miRNAs) are a class of short noncoding RNAs that modulate gene expression at both transcriptional and post-transcriptional levels. Many studies have extensively revealed the significance of miRNAs in mediating liver development and diseases. However, their role in hepatic detoxification processes has been explored only recently. In this review, we summarized the up-to-date knowledge about miRNA dependent regulation of enzymes involved in all three phases of the drugs and xenobiotics detoxification process. We also discussed the role of miRNA in regulating some upstream nuclear receptors involving gene expression of enzymes for detoxification process in liver. The toxicological significance of miRNAs in liver diseases and future research perspectives are finally presented.

miR-513a-5p regulates radiosensitivity of osteosarcoma by targeting human apurinic/apyrimidinic endonuclease

Radiotherapy in osteosarcoma patients is problematic due to radioresistance; therefore, understanding the mechanism of radioresistance is integral to providing effective radiotherapeutic regimens for osteosarcoma. We now report the activity of an miRNA, miR-513a-5p, in stimulating radiosensitivity of osteosarcoma cells in vitro and in vivo. MiR-513a-5p expression is decreased in osteosarcoma tissue from patients and cultured osteosarcoma cell lines. However, exogenous re-expression of this miRNA in osteosarcoma cell lines, including HOS, U2OS and 9901, can induce sensitization to ionizing radiation. We also confirm that miR-513a-5p suppresses APE1 expression, and that both the redox and DNA repair activity of APE1 were decreased in miR-513a-5p expressing cell lines. By suppressing APE1, miR-513a-5p induces the DNA damage response which stimulates apoptosis after irradiation. Our report establishes miR-513a-5p as a radiosensitizing miRNA and identifies its activity in the suppression of APE1, which could directly lead to radiosensitization.

Targeting DNA Damage Response in the Radio(Chemo)therapy of Non-Small Cell Lung Cancer

Lung cancer is the leading cause of cancer death worldwide due to its high incidence and mortality. As the most common lung cancer, non-small cell lung cancer (NSCLC) is a terrible threat to human health. Despite improvements in diagnosis and combined treatments including surgical resection, radiotherapy and chemotherapy, the overall survival for NSCLC patients still remains poor. DNA damage is considered to be the primary cause of lung cancer development and is normally recognized and repaired by the intrinsic DNA damage response machinery. The role of DNA repair pathways in radio(chemo)therapy-resistant cancers has become an area of significant interest in the clinical setting. Meanwhile, some studies have proved that genetic and epigenetic factors can alter the DNA damage response and repair, which results in changes of the radiation and chemotherapy curative effect in NSCLC. In this review, we focus on the effect of genetic polymorphisms and epigenetic factors such as miRNA regulation and lncRNA regulation participating in DNA damage repair in response to radio(chemo)therapy in NSCLC. These may provide novel information on the radio(chemo)therapy of NSCLC based on the individual DNA damage response.

The effects of microRNA on the absorption, distribution, metabolism and excretion of drugs

The importance of genetic factors (e.g. sequence variation) in the absorption, distribution, metabolism, excretion (ADME) and overall efficacy of therapeutic agents is well established. Our ability to identify, interpret and utilize these factors is the subject of much clinical investigation and therapeutic development. However, drug ADME and efficacy are also heavily influenced by epigenetic factors such as DNA/histone methylation and non-coding RNAs [especially microRNAs (miRNAs)]. Results from studies using tools, such as in silico miRNA target prediction, in vitro functional assays, nucleic acid profiling/sequencing and high-throughput proteomics, are rapidly expanding our knowledge of these factors and their effects on drug metabolism. Although these studies reveal a complex regulation of drug ADME, an increased understanding of the molecular interplay between the genome, epigenome and transcriptome has the potential to provide practically useful strategies to facilitate drug development, optimize therapeutic efficacy, circumvent adverse effects, yield novel diagnostics and ultimately become an integral component of personalized medicine.

Expression profile of plasma microRNAs in premature infants with respiratory distress syndrome

As well-known regulators of gene expression, microRNAs (miRNAs) are important not only in cell proliferation and differentiation, but also in tumorigenesis and organ development. It has been estimated that miRNAs may be responsible for regulating the expression of almost one third of the human genome. Simultaneously, with advances in neonatal care in the clinic, an increased number of premature infants are being saved and, thus, respiratory distress syndrome (RDS) has become more common. However, previous non-miRNA studies have suggested their connection with RDS. In the present study, a miRNA microarray, including >1,891 capture probes was used to compared the expression profiles of plasma miRNAs between RDS and control groups. miRNAs, which were observed to have consistent fold-changes (fold-change ≥ 1.3) between the two groups were selected and validated using reverse transcription-quantitative polymerase chain reaction. As a result, 171 differentially expressed miRNAs were identified, including two upregulated and seven downregulated miRNAs. Of these miRNAs, four were selected as having higher fold-changes between the two groups. This is the first time, to the best of our knowledge, that these nine miRNAs have been reported in RDS. It was hypothesized that these novel miRNAs may be important in RDS, and may provide meaningful biomarkers for the diagnosis of RDS.

Non-small-cell lung cancer and miRNAs: novel biomarkers and promising tools for treatment

Lung cancer is the leading cause of cancer-related death worldwide, with approximately 80–85% of cases being non-small-cell lung cancer (NSCLC). The miRNAs are small non-coding RNAs that regulate gene expression at a post-transcriptional level by either degradation or inhibition of the translation of target genes. Evidence is mounting that miRNAs exert pivotal effects in the development and progression of human malignancies, including NSCLC. A better understanding of the role that miRNAs play in the disease will contribute to the development of new diagnostic biomarkers and individualized therapeutic tools. In the present review, we briefly describe the role of miRNAs in NSCLC as well as the possible future of these discoveries in clinical applications.

microRNA and Lung Cancer

Lung cancer is the leading cause of cancer mortality worldwide. microRNAs (miRNAs) have been established as players with a relevant role in lung cancer development, epithelial-mesenchymal transition and response to therapy. Additionally, in the last decade, miRNAs, measured in resected tumor samples or in fine-needle aspirate samples have emerged as compelling biomarkers for tumor diagnosis, prognosis, and prediction of response to treatment, due to the ease of their detection and in their extreme specificity. Moreover, miRNAs present in sputum, in plasma, in serum or in whole-blood have increasingly been explored in the last 5 years as less invasive biomarkers for the early detection of cancers.