NEAT1 upregulates EGCG-induced CTR1 to enhance cisplatin sensitivity in lung cancer cells

Genetic variants in long non-coding RNAs UCA1 and NEAT1 were associated with the prognosis of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is known for its high incidence, death rate, and relatively low 5-year survival. Long non-coding RNAs (lncRNAs) have been shown to play a significant role in cancerization and cancer progression. However, research on the association of polymorphisms in these lncRNAs with the prognosis of OSCC is lacking. Fifteen functional single-nucleotide polymorphisms (SNPs) in seven lncRNAs were selected to explore the relationship between these lncRNA SNPs and the prognosis among 209 OSCC patients. Kaplan-Meier analysis and Cox proportional hazards regression models were used to examine the associations. Further functional exploration of significant SNPs was done by eQTL analysis. Using multivariate Cox hazards regression analysis, a predictive role of NEAT1 rs3741384 GG and UCA1 rs7255437 TC+TT in a worse prognosis of OSCC was identified. In addition, a marked increased risk of death was observed with an increasing number of unfavourable genotypes (NUG). The NUG was then incorporated with clinical variables in the receiver operating characteristic curve, and the results indicated a potential role of the NUG in predicting OSCC patient risk of death (area under the curve increase from 0.616 to 0.703). In conclusion, the study findings indicate that genetic variants rs3741384 in NEAT and rs7255437 in UCA1 may influence the survival of OSCC patients.

The interplay between ATF2 and NEAT1 contributes to lung adenocarcinoma progression

Background

Activating transcription factor 2 (ATF2), a member of the activator protein 1 (AP-1) transcription factor family, has been shown to be involved in the pathobiology of numerous cancers. However, the biological role and mechanism of ATF2 in lung adenocarcinoma (LUAD) remains to be elucidated.

Methods

The expression of ATF2, NEAT1 and miR-26a-5p in LUAD tissues and cell lines was detected by qRT-PCR and western blotting. The interaction between ATF2, NEAT1, and miR-26a-5p was validated by chromatin immunoprecipitation, luciferase reporter assay and RNA immunoprecipitation. Cell proliferation, invasion and tumorigenesis of LUAD cells were analyzed by using CCK8, transwell invasion assay and xenograft tumor model.

Results

We confirmed that ATF2 expression was increased in LUAD tissues compared with normal adjacent lung tissues. Functional experiments showed that ATF2 positively regulated cell proliferation and invasion in LUAD cells. Moreover, we identified that NEAT1 expression was increased in LUAD tissues and positively correlated with ATF2 expression. Mechanistically, ATF2 could bind to the promoter of NEAT1 to promote its transcription. Rescue experiments showed that ATF2 exerted its oncogenic function in LUAD, at least, partly through NEAT1 upregulation. In turn, NEAT1 could positively regulate ATF2 expression and form a positive feedback loop in LUAD cells. Furthermore, we demonstrated that NEAT1 positively regulated ATF2 expression via sponging miR-26a-5p.

Conclusion

ATF2 and NEAT1 form a positive feedback loop mediated by miR-26a-5p and coordinately contribute to LUAD progression.

Non coding RNAs as the critical factors in chemo resistance of bladder tumor cells

BACKGROUND

Bladder cancer (BCa) is the ninth frequent and 13th leading cause of cancer related deaths in the world which is mainly observed among men. There is a declining mortality rates in developed countries. Although, the majority of BCa patients present Non-Muscle-Invasive Bladder Cancer (NMIBC) tumors, only 30% of patients suffer from muscle invasion and distant metastases. Radical cystoprostatectomy, radiation, and chemotherapy have proven to be efficient in metastatic tumors. However, tumor relapse is observed in a noticeable ratio of patients following the chemotherapeutic treatment. Non-coding RNAs (ncRNAs) are important factors during tumor progression and chemo resistance which can be used as diagnostic and prognostic biomarkers of BCa.

MAIN BODY

In present review we summarized all of the lncRNAs and miRNAs associated with chemotherapeutic resistance in bladder tumor cells.

CONCLUSIONS

This review paves the way of introducing a prognostic panel of ncRNAs for the BCa patients which can be useful to select a proper drug based on the lncRNA profiles of patients to reduce the cytotoxic effects of chemotherapy in such patients.

Mechanisms of drug resistance mediated by long non-coding RNAs in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is the most prevalent form of lung cancer and has a poor five-year survival rate of 15%. Chemotherapy and targeted therapies have significantly improved patients' prognosis. Nevertheless, after a successful initial response, some patients relapse when cancer cells become resistant to drug treatments, representing an important clinical limitation. Therefore, investigating the mechanisms of drug resistance is of significant importance. Recently, considerable attention has been given to long non-coding RNAs (lncRNAs), a heterogeneous class of regulatory molecules that play essential roles in tumorigenesis by modulating genes and signalling pathways involved in cell growth, metastasis and drug response. In this article, we review recent research findings on the role of lncRNAs in drug resistance in NSCLC, highlighting their mechanisms of action.

Back to the Future: Rethinking the Great Potential of lncRNAS for Optimizing Chemotherapeutic Response in Ovarian Cancer

Ovarian cancer (OC) is one of the most fatal cancers in women worldwide. Currently, platinum- and taxane-based chemotherapy is the mainstay for the treatment of OC. Yet, the emergence of chemoresistance results in therapeutic failure and significant relapse despite a consistent rate of primary response. Emerging evidence substantiates the potential role of lncRNAs in determining the response to standard chemotherapy in OC. The objective of this narrative review is to provide an integrated, synthesized overview of the current state of knowledge regarding the role of lncRNAs in the emergence of resistance to platinum- and taxane-based chemotherapy in OC. In addition, we sought to develop conceptual frameworks for harnessing the therapeutic potential of lncRNAs in strategies aimed at enhancing the chemotherapy response of OC. Furthermore, we offered significant new perspectives and insights on the interplay between lncRNAs and the molecular circuitries implicated in chemoresistance to determine their impacts on therapeutic response. Although this review summarizes robust data concerning the involvement of lncRNAs in the emergence of acquired resistance to platinum- and taxane-based chemotherapy in OC, effective approaches for translating these lncRNAs into clinical practice warrant further investigation.

ALKBH5 promotes colon cancer progression by decreasing methylation of the lncRNA NEAT1

Colon cancer is the third leading cause of cancer-related deaths all around the world. LncRNA methylation has been verified to participate in some kinds of malignancies. The aim of this study was to investigate the function of NEAT1 in colon cancer and further explore the potential mechanism between NEAT1 and ALKBH5. Differential expression of lncRNAs between colon cancer tissues and normal tissues was identified using ArrayStar lncRNA microarrays. The levels of NEAT1 and ALKBH5 expression in colon cancer tissues and cells were measured using qRT-PCR. MTT, transwell migration assays and qRT-PCR were performed to detect cell proliferation and migration. Flow cytometry and qRT-PCR was used for apoptosis analysis. Then, m6A RNA immunoprecipitation was performed to detect methylated NEAT1 in colon cancer cells. The results showed NEAT1 was remarkably enhanced in colon cancer tissues and correlated with poor prognosis. Knockdown of NEAT1 inhibited cell proliferation and migration, induced cell apoptosis in colon cancer cell lines. Besides, ALKBH5 could upregulate NEAT1 expression by demethylation. In addition, ALKBH5 knockdown suppressed malignant behavior of colon cancer partially through NEAT1 in vitro and vivo. In a word, we observed NEAT1 expression level was up-regulated in colon cancer tissues and cells. ALKBH5 knockdown suppressed malignant behavior of colon cancer partially through NEAT1 by demethylation in vitro and vivo, suggesting that ALKBH5-NEAT1 axis maybe potential therapeutic target for colon cancer treatment.

NEAT1 Knockdown Suppresses the Cisplatin Resistance in Ovarian Cancer by Regulating miR-770-5p/PARP1 Axis

Background

Long noncoding RNAs play essential roles in regulating drug resistance in cancers. However, how and whether lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) could mediate cisplatin resistance in ovarian cancer remain poorly understood.

Patients and Methods

Eighteen cisplatin-sensitive and 19 cisplatin-resistant patients with ovarian cancer were recruited. Cisplatin-resistant ovarian cancer cells were used for this study. The expression levels of NEAT1, microRNA (miR)-770-5p and poly adenosine diphosphate-ribose polymerase 1 (PARP1) were detected by quantitative real-time polymerase chain reaction or Western blot. Cisplatin resistance was assessed by the half-maximal inhibitory concentration (IC50) of cisplatin, cell viability and apoptosis using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, flow cytometry and Western blot, respectively. The target association between miR-770-5p and NEAT1 or PARP1 was investigated by dual-luciferase reporter assay. The xenograft model was used to investigate cisplatin resistance in vivo.

Results

NEAT1 expression is elevated in cisplatin-resistant ovarian cancer tissues and cells. Knockdown of NEAT1 repressed cisplatin resistance by decreasing the IC50 of cisplatin, cell viability and increasing apoptosis. MiR-770-5p was bound to NEAT1 and PARP1 was confirmed as a target of miR-770-5p. MiR-770-5p inhibition or PARP1 restoration could abate the effect of NEAT1 silencing on cisplatin resistance in cisplatin-resistant ovarian cancer cells. Moreover, NEAT1 knockdown reduced PARP1 expression by increasing miR-770-5p. Interference of NEAT1 decreased xenograft tumor growth by regulating miR-770-5p and PARP1.

Conclusion

Knockdown of NEAT1 inhibited cisplatin resistance in ovarian cancer cells by up-regulating miR-770-5p and down-regulating PARP1, providing a new target for improving the efficacy of cisplatin-based therapy in ovarian cancer.

LncRNA HEIH Confers Cell Sorafenib Resistance in Hepatocellular Carcinoma by Regulating miR-98-5p/PI3K/AKT Pathway

Background

The hepatocellular carcinoma up-regulated EZH2-associated long non-coding RNA (HEIH) has been identified to act as an oncogene to promote cell tumorigenesis in hepatocellular carcinoma (HCC); however, the roles of HEIH in sorafenib resistance in HCC cells remain elusive.

Materials and Methods

The expression of HEIH and microRNA (miR)-98-5p was detected using quantitative real-time polymerase chain reaction. Cell viability, apoptosis, migration and invasion were analyzed using cell counting kit-8 assay, flow cytometry and transwell assay. Western blot was used to measure the levels of apoptosis-related protein and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway-related protein. The interaction between HEIH and miR-98-5p was confirmed by dual-luciferase reporter and RNA immunoprecipitation assay. In vivo experiments were performed using murine xenograft models.

Results

HEIH was up-regulated in sorafenib-resistant HCC tissues and cell lines, and HEIH silence weakened sorafenib resistance by suppressing cell viability, invasion and migration, decreasing the IC₅₀ values to sorafenib, and increasing apoptosis in sorafenib-resistant HCC cells in vitro and reinforced the anti-tumor effects of sorafenib in vivo. HEIH was a sponge of miR-98-5p, and miR-98-5p inhibition reversed the sorafenib sensitivity induced by HEIH deletion in sorafenib-resistant HCC cells. MiR-98-5p inhibition could activate PI3K/AKT pathway, and enhanced sorafenib resistance by regulating the activation of PI3K/AKT pathway in sorafenib-resistant HCC cells. Besides, HEIH also activated PI3K/AKT pathway through regulating miR-98-5p in sorafenib-resistant HCC cells.

Conclusion

HEIH conferred an advantage to sorafenib resistance in HCC by the activation of PI3K/AKT pathway through miR-98-5p, indicating a potential therapeutic strategy for HCC chemotherapy.

lncRNA RP11-838N2.3 Promoted Cisplatin Resistance in Lung Adenocarcinoma

The mechanism of RP11-838N2.3 promoting cisplatin resistance in lung adenocarcinoma (LAD) was unclear. The RP11-838N2.3 expression level in cells and LAD tissues was detected by qPCR. We constructed lentivirus-mediated GV303 overexpression and GV248 shRNA vector targeting RP11-838N2.3, then infected A549 and A549/DDP cell and furtherly analyzed cell biology. High-throughput gene chip analysis showed that RP11-838N2.3 was significantly upregulated in A549/DDP (change fold = 66.056595). The qPCR results showed that the expression level of RP11-838N2.3 in A549/DDP cell was significantly higher than that in A549 cells (P < 0.05), and the expression level of RP11-838N2.3 in LAD tissues was also significantly higher than that in adjacent tissues (P < 0.05). The expression level of RP11-838N2.3 in cisplatin-insensitive LAD tissues was also significantly higher than that in cisplatin-sensitive LAD tissues (P < 0.05). Survival analysis showed that OS (overall survival) and DFS (progression-free survival) of high RP11-838N2.3 expression in the cisplatin-sensitive or cisplatin-insensitive LAD group were lower (P < 0.001 and P < 0.001) than those of low RP11-838N2.3 expression in the cisplatin-sensitive or cisplatin-insensitive LAD group. CCK8 showed that the OD450 value of RP11-838N2.3 overexpression increased significantly at 24 h, 48 h, and 72 h after transfection, while the knockdown of RP11-838N2.3 caused OD450 value at 24 h, 48 h, and 72 h after transfection significantly reduced, under the action of cisplatin that had the same trend (P < 0.05). The cell migration showed that the RP11-838N2.3 overexpression increased significantly migration activity and RP11-838N2.3 knockdown inhibited migration activity at 24 h, 48 h, and 72 h after transfection. The same trend was also observed under the action of cisplatin (P < 0.05). The cell invasion showed that the invasion rate of RP11-838N2.3 overexpression increased significantly, while the invasion rate of RP11-838N2.3 knockdown decreased significantly, and the same trend was observed under the action of cisplatin (P < 0.05). Apoptosis results showed that the apoptosis rate of RP11-838N2.3 overexpressed cells decreased significantly and the apoptosis rate of RP11-838N2.3 knockdown cells increased significantly, and the same trend was also observed under the action of cisplatin (P < 0.05). However, the results of cell cycle showed that there was no significant difference in the proportion of cells in each phase of the cell cycle after RP11-838N2.3 overexpression or knockdown (P > 0.05).RP11-838N2.3 was significantly upregulated in cisplatin-resistant cell and tissues of LAD. RP11-838N2.3 could enhance the proliferation, migration, and invasion and inhibit apoptosis of LAD cisplatin-resistant cell. So RP11-838N2.3 could enhance the cisplatin resistance of LAD cells and was a resistant lncRNA molecule.

Natural compounds modulate the crosstalk between apoptosis- and autophagy-regulated signaling pathways: Controlling the uncontrolled expansion of tumor cells

Due to the high number of annual cancer-related deaths, and the economic burden that this malignancy affects today's society, the study of compounds isolated from natural sources should be encouraged. Most cancers are the result of a combined effect of lifestyle, environmental factors, and genetic and hereditary components. Recent literature reveals an increase in the interest for the study of phytochemicals from traditional medicine, this being a valuable resource for modern medicine to identify novel bioactive agents with potential medicinal applications. Phytochemicals are components of traditional medicine that are showing promising application in modern medicine due to their antitumor activities. Recent studies regarding two major mechanisms underlying cancer development and regulation, apoptosis and autophagy, have shown that the signaling pathways of both these processes are significantly interconnected through various mechanisms of crosstalk. Phytochemicals are able to activate pro-autophagic and pro-apoptosis mechanisms. Understanding the molecular mechanism involved in apoptosis-autophagy relationship modulated by phytochemicals plays a key role in development of a new therapeutic strategy for cancer treatment. The purpose of this review is to outline the bioactive properties of the natural phytochemicals with validated antitumor activity, focusing particularly on their role in the regulation of apoptosis and autophagy crosstalk that triggers the uncontrolled expansion of tumor cells. Furthermore, we have also critically discussed the limitations and challenges of existing research strategies and the prospective research directions in this field.

Molecular mechanisms of action of epigallocatechin gallate in cancer: Recent trends and advancement

Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is an ester of epigallocatechin and gallic acid. EGCG, abundantly found in tea, is a polyphenolic flavonoid that has the potential to affect human health and disease. EGCG interacts with various recognized cellular targets and inhibits cancer cell proliferation by inducing apoptosis and cell cycle arrest. In addition, scientific evidence has illustrated the promising role of EGCG in inhibiting tumor cell metastasis and angiogenesis. It has also been found that EGCG may reverse drug resistance of cancer cells and could be a promising candidate for synergism studies. The prospective importance of EGCG in cancer treatment is owed to its natural origin, safety, and low cost which presents it as an attractive target for further development of novel cancer therapeutics. A major challenge with EGCG is its low bioavailability which is being targeted for improvement by encapsulating EGCG in nano-sized vehicles for further delivery. However, there are major limitations of the studies on EGCG, including study design, experimental bias, and inconsistent results and reproducibility among different study cohorts. Additionally, it is important to identify specific EGCG pharmacological targets in the tumor-specific signaling pathways for development of novel combined therapeutic treatments with EGCG. The present review highlights the ongoing development to identify cellular and molecular targets of EGCG in cancer. Furthermore, the role of nanotechnology-mediated EGCG combinations and delivery systems will also be discussed.

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

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

Research Progress on Long Non-coding RNAs and Drug Resistance of Breast Cancer

Breast cancer, as the foremost cause of women's death in the world, is highly metastatic and mutable. Resistance to drugs for chemotherapies, endocrine therapies, and targeted therapies is an important factor that impacts the prognosis of breast cancer. Long non-coding ribonucleic acids (LncRNAs) are crucial regulators of intracellular gene expressions. Some researchers have suggested that expression level of several types of LncRNAs were closely related to the prognosis of patients with breast cancer. LncRNAs significantly impact biological processes such as drug transport, detoxication, apoptosis, epithelial to mesenchymal transition (EMT), and autophagy by regulating intracellular signaling pathways such as multi-drug resistance gene 1 (MDR1), nuclear factor erythroid 2-related factor 2 (NRF2), phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), transforming growth factor-β (TGF-β), BRCA1/2, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). This paper will summarize research progress on correlations between LncRNA and drug resistance of breast cancer. It will particularly expound molecular mechanisms through which LncRNAs regulate drug resistance of breast cancer. It will further discuss the feasibility as molecular markers for forecasting drug resistance of breast cancer and may be becoming new targets for treating breast cancer in the future.

EGCG Mediated Targeting of Deregulated Signaling Pathways and Non-Coding RNAs in Different Cancers: Focus on JAK/STAT, Wnt/β-Catenin, TGF/SMAD, NOTCH, SHH/GLI, and TRAIL Mediated Signaling Pathways

Decades of research have enabled us to develop a better and sharper understanding of multifaceted nature of cancer. Next-generation sequencing technologies have leveraged our existing knowledge related to intra- and inter-tumor heterogeneity to the next level. Functional genomics have opened new horizons to explore deregulated signaling pathways in different cancers. Therapeutic targeting of deregulated oncogenic signaling cascades by products obtained from natural sources has shown promising results. Epigallocatechin-3-gallate (EGCG) has emerged as a distinguished chemopreventive product because of its ability to regulate a myriad of oncogenic signaling pathways. Based on its scientifically approved anticancer activity and encouraging results obtained from preclinical trials, it is also being tested in various phases of clinical trials. A series of clinical trials associated with green tea extracts and EGCG are providing clues about significant potential of EGCG to mechanistically modulate wide ranging signal transduction cascades. In this review, we comprehensively analyzed regulation of JAK/STAT, Wnt/β-catenin, TGF/SMAD, SHH/GLI, NOTCH pathways by EGCG. We also discussed most recent evidence related to the ability of EGCG to modulate non-coding RNAs in different cancers. Methylation of the genome is also a widely studied mechanism and EGCG has been shown to modulate DNA methyltransferases (DNMTs) and protein enhancer of zeste-2 (EZH2) in multiple cancers. Moreover, the use of nanoformulations to increase the bioavailability and thus efficacy of EGCG will be also addressed. Better understanding of the pleiotropic abilities of EGCG to modulate intracellular pathways along with the development of effective EGCG delivery vehicles will be helpful in getting a step closer to individualized medicines.

EGCG regulates CTR1 expression through its pro-oxidative property in non-small-cell lung cancer cells

Copper transporter 1 (CTR1) plays an important role in increasing cisplatin intake. Our previous studies showed that CTR1 expression was upregulated by (-)-epigallocatechin-3-gallate (EGCG), a green tea polyphenol, therefore enhanced cisplatin sensitivity in ovary cancer and non-small-cell lung cancer (NSCLC) cells. In the current study in the non-small-cell lung cancer cells, we uncovered a potential mechanism of EGCG-induced CTR1 through its pro-oxidative property. We found that EGCG increased reactive oxygen species (ROS) generation, while in the presence of ROS scavenger N-acetyl-cysteine (NAC), ROS production was eliminated. Changes of CTR1 expression were consistent with the ROS level. Simultaneously, EGCG downregulated ERK1/2 while upregulated lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) through ROS to induce CTR1 expression. Besides, in a nude mouse xenografts model, EGCG treatment raised ROS level, expression of CTR1 and NEAT1 in tumor tissue. Also, ERK1/2 and p-ERK1/2 were suppressed as well. Taken together, these results suggested a novel mechanism that EGCG mediated ROS to regulate CTR1 expression through the ERK1/2/NEAT1 signaling pathway, which provided more possibilities for EGCG as a natural agent in adjuvant therapy of lung cancer.

Identification of drug resistance associated ncRNAs based on comprehensive heterogeneous network

AIMS

Chemotherapy and molecularly targeted therapy are main strategies for treatment of cancers. However, long-term treatment makes cancer cells acquire resistance to anti-cancer drugs, which severely limits the effects of cancer treatment. NcRNAs, especially miRNAs and lncRNAs, have been reported to play key roles in drug resistance and could restore drug responses in resistant cells.

MAIN METHODS

We presented a network-based framework to systematically identify drug resistance associated miRNAs and lncRNAs. First, we constructed a comprehensive heterogeneous miRNA-lncRNA regulatory network through integrating curated miRNA regulations to lncRNA, and significantly co-expressed miRNA-miRNA, lncRNA-lncRNA and miRNA-lncRNA interactions for each cancer type. Second, random walk with restart (RWR) was utilized to identify novel drug resistance associated ncRNAs.

KEY FINDINGS

We predicted 470 associations of 34 miRNAs and 79 lncRNAs for 27 drugs in 10 cancer types. In addition, leave-one-out cross validation (LOOCV) demonstrated the effectiveness of the proposed approach. Next, we also demonstrated that the integrated heterogeneous cancer-specific network achieved better performance than the general curated miRNA-lncRNA regulatory network. What's more, we found that the drug resistance associated ncRNAs validated by high-throughput technology was also a reliable source for prediction.

SIGNIFICANCE

We proposed a new framework to identify novel and reliable drug resistance associated ncRNAs, which provides new perspectives for drug resistance mechanism and new guidance for clinical cancer treatment.

Long-noncoding RNAs (lncRNAs) in drug metabolism and disposition, implications in cancer chemo-resistance

Drug metabolism is an orchestrated process in which drugs are metabolized and disposed through a series of specialized enzymes and transporters. Alterations in the expression and/or activity of these enzymes and transporters can affect the bioavailability (pharmacokinetics, or PK) and therapeutic efficacy (pharmacodynamics, or PD) of drugs. Recent studies have suggested that the long non-coding RNAs (lncRNAs) are highly relevant to drug metabolism and drug resistance, including chemo-resistance in cancers, through the regulation of drug metabolism and disposition related genes. This review summarizes the regulation of enzymes, transporters, or regulatory proteins involved in drug metabolism by lncRNAs, with a particular emphasis on drug metabolism and chemo-resistance in cancer patients. The perspective strategies to integrate multi-dimensional pharmacogenomics data for future in-depth analysis of drug metabolism related lncRNAs are also proposed. Understanding the role of lncRNAs in drug metabolism will not only facilitate the identification of novel regulatory mechanisms, but also enable the discovery of lncRNA-based biomarkers and drug targets to personalize and improve the therapeutic outcome of patients, including cancer patients.

Long non-coding RNAs in non-small cell lung cancer: functions and distinctions from other malignancies

Lung cancer leads to the most cancer-related death in the world. It was shown from the increasing evidences that long non-coding RNAs (lncRNAs) are emerging as molecules for diagnosis, prognosis and even therapy of lung cancer and other malignancies. The biological functions or involved signaling pathways of lncRNAs are always found to be inconsistent among different types of malignancies. However, no available literature has systemically summarized differences in the functions and underlying molecular mechanisms of lncRNAs between lung cancer and other cancers. In this review, the biological functions and molecular mechanisms of lncRNAs in lung cancer were introduced. Furthermore, their functional differences between lung cancer and other malignancies were discussed. Finally, their potential clinical applications in future lung cancer therapy were focused on.

Tea and Its Components Prevent Cancer: A Review of the Redox-Related Mechanism

Cancer is a worldwide epidemic and represents a major threat to human health and survival. Reactive oxygen species (ROS) play a dual role in cancer cells, which includes both promoting and inhibiting carcinogenesis. Tea remains one of the most prevalent beverages consumed due in part to its anti- or pro-oxidative properties. The active compounds in tea, particularly tea polyphenols, can directly or indirectly scavenge ROS to reduce oncogenesis and cancerometastasis. Interestingly, the excessive levels of ROS induced by consuming tea could induce programmed cell death (PCD) or non-PCD of cancer cells. On the basis of illustrating the relationship between ROS and cancer, the current review discusses the composition and efficacy of tea including the redox-relative (including anti-oxidative and pro-oxidative activity) mechanisms and their role along with other components in preventing and treating cancer. This information will highlight the basis for the clinical utilization of tea extracts in the prevention or treatment of cancer in the future.

In silico identification of thiostrepton as an inhibitor of cancer stem cell growth and an enhancer for chemotherapy in non-small-cell lung cancer

Cancer stem cells (CSCs) play an important role in cancer treatment resistance and disease progression. Identifying an effective anti-CSC agent may lead to improved disease control. We used CSC-associated gene signatures to identify drug candidates that may inhibit CSC growth by reversing the CSC gene signature. Thiostrepton, a natural cyclic oligopeptide antibiotic, was the top-ranked candidate. In non-small-cell lung cancer (NSCLC) cells, thiostrepton inhibited CSC growth in vitro and reduced protein expression of cancer stemness markers, including CD133, Nanog and Oct4A. In addition, metastasis-associated Src tyrosine kinase signalling, cell migration and epithelial-to-mesenchymal transition (EMT) were all inhibited by thiostrepton. Mechanistically, thiostrepton treatment led to elevated levels of tumour suppressor miR-98. Thiostrepton combined with gemcitabine synergistically suppressed NSCLC cell growth and induced apoptosis. The inhibition of NSCLC tumours and CSC growth by thiostrepton was also demonstrated in vivo. Our findings indicate that thiostrepton, an established drug identified in silico, is an inhibitor of CSC growth and a potential enhancer of chemotherapy in NSCLC.

(-)-Epigallocatechin-3-gallate derivatives combined with cisplatin exhibit synergistic inhibitory effects on non-small-cell lung cancer cells

Background

Non-small-cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. The inhibition of epidermal growth factor receptor (EGFR) signaling by tyrosine kinase inhibitors or monoclonal antibodies plays a key role in NSCLC treatment. Unfortunately, these treatment strategies are limited by eventual resistance and cell lines with differential EGFR status. Therefore, new therapeutic strategies for NSCLC are urgently required.

Methods

To improve the stability and absorption of (−)-epigallocatechin-3-gallate (EGCG), we synthesized a series of EGCG derivatives. The antitumor activities of EGCG derivatives with or without cisplatin were investigated in vitro and vivo. Cell proliferation, cell cycle distribution and apoptosis were measured in NSCLC cell lines and in vivo in a NCI-H441 xenograft model.

Results

We found that the EGCG derivatives inhibited cell viability and colony formation, caused cell cycle redistribution, and induced apoptosis. More importantly, the combination of the EGCG derivative and cisplatin led to increased growth inhibition, caused cell cycle redistribution, and enhanced the apoptosis rate compared to either compound alone. Consistent with the experiments in vitro, EGCG derivatives plus cisplatin significantly reduced tumor growth.

Conclusions

The combination treatment was found to inhibit the EGFR signaling pathway and decrease the expression of p-EGFR, p-AKT, and p-ERK in vitro and vivo. Our results suggest that compound 3 is a novel potential compound for NSCLC patients.

LncRNA NEAT1 enhances the resistance of anaplastic thyroid carcinoma cells to cisplatin by sponging miR‑9‑5p and regulating SPAG9 expression

Anaplastic thyroid carcinoma (ATC) has a poor prognosis due to its resistance to all conventional treatments. The long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) serves a critical role in cancer chemoresistance; however, whether NEAT1 is associated with chemoresistance of ATC remains unclear. In the present study, reverse transcription-quantitative PCR assays were performed to detect the expression levels of NEAT1, microRNA (miR)-9-5p and sperm-associated antigen 9 (SPAG9). Western blot analysis was conducted to assess the protein expression levels of p62, microtubule-associated proteins 1A/1B light chain 3B and SPAG9. Cell proliferation was detected using the Cell Counting kit-8 assay, and cell apoptosis was determined by flow cytometry. Dual-luciferase reporter and RNA immunoprecipitation assays were performed to verify the interaction between NEAT1 and miR-9-5p, or miR-9-5p and SPAG9. Furthermore, an animal model was used to investigate the regulatory effects of NEAT1 on cisplatin (DDP)-resistance in tumors in vivo. The present results demonstrated that NEAT1 was upregulated in ATC tissues and cell lines, and NEAT1 silencing resulted in decreased DDP-resistance of ATC cells. In addition, NEAT1 suppressed miR-9-5p expression by binding to miR-9-5p and SPAG9 was a direct target of miR-9-5p. miR-9-5p overexpression sensitized ATC cells to DDP. Notably, NEAT1 silencing exerted its inhibitory effect on DDP-resistance of ATC via the miR-9-5p/SPAG9 axis in vitro and in vivo. In conclusion, the present study demonstrated that NEAT1 silencing ameliorated DDP-resistance of ATC, at least in part by reducing miR-9-5p sponging and regulating SPAG5 expression; therefore, NEAT1 may be considered a potential therapeutic target of ATC.

Progress in Research on the Role of Flavonoids in Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide. Therefore, for the prevention, diagnosis, prognosis and treatment of lung cancer, efficient preventive strategies and new therapeutic strategies are needed to face these challenges. Natural bioactive compounds and particular flavonoids compounds have been proven to have an important role in lung cancer prevention and of particular interest is the dose used for these studies, to underline the molecular effects and mechanisms at a physiological concentration. The purpose of this review was to summarize the current state of knowledge regarding relevant molecular mechanisms involved in the pharmacological effects, with a special focus on the anti-cancer role, by regulating the coding and non-coding genes. Furthermore, this review focused on the most commonly altered and most clinically relevant oncogenes and tumor suppressor genes and microRNAs in lung cancer. Particular attention was given to the biological effect in tandem with conventional therapy, emphasizing the role in the regulation of drug resistance related mechanisms.

Long noncoding RNA NEAT1 suppresses sorafenib sensitivity of hepatocellular carcinoma cells via regulating miR-335-c-Met

OBJECTIVES

To investigate the role of long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) in regulating sorafenib (Sora) sensitivity of hepatocellular carcinoma (HCC) cells and possible signaling pathways.

METHODS

HCC cell lines and tumor tissue were quantified for NEAT1 expression by quantitative polymerase chain reaction (qPCR). Following shRNA (short hairpin RNA) knockdown of NEAT1, cell viability, apoptosis, and related protein expression were measured after drug treatment. The downstream target of NEAT1, including miR-335 and c-Met was studied using a combination of luciferase binding assay, gene knockdown/overexpression, western blot analysis, and cell viability/apoptosis assay. Cancer cells with NEAT1 knockdown were transplanted onto nude mice for in vivo tumorigenesis assay.

RESULTS

Silencing of NEAT1 in HCC cells facilitated Sora sensitivity by enhancing drug-induced apoptosis, and led to smaller tumor size on nude mice. Mechanistic study suggested that miR-335 was negatively regulated by NEAT1, and miR-335 further suppressed c-Met-Akt pathway, whose activation caused drug resistance of HCC cells. The knockdown of miR-335, or overexpression of c-Met, all remarkably abolished the proapoptotic effect of NEAT1 knockdown in HCC cells.

CONCLUSION

lncRNA NEAT1 mediates Sora resistance of HCC cells by suppressing miR-335 expression, and disinhibition on c-Met-Akt signaling pathway. Our results provide potency of NEAT1 as the biomarker for drug resistant HCC and possible treating targets.

Phytochemicals as Modulators of Long Non-Coding RNAs and Inhibitors of Cancer-Related Carbonic Anhydrases

Long non-coding RNAs (lncRNAs) are classified as a group of transcripts which regulate various biological processes, such as RNA processing, epigenetic control, and signaling pathways. According to recent studies, lncRNAs are dysregulated in cancer and play an important role in cancer incidence and spreading. There is also an association between lncRNAs and the overexpression of some tumor-associated proteins, including carbonic anhydrases II, IX, and XII (CA II, CA IX, and CA XII). Therefore, not only CA inhibition, but also lncRNA modulation, could represent an attractive strategy for cancer prevention and therapy. Experimental studies have suggested that herbal compounds regulate the expression of many lncRNAs involved in cancer, such as HOTAIR (HOX transcript antisense RNA), H19, MALAT1 (metastasis-associated lung adenocarcinoma transcript 1), PCGEM1 (Prostate cancer gene expression marker 1), PVT1, etc. These plant-derived drugs or phytochemicals include resveratrol, curcumin, genistein, quercetin, epigallocatechin-3-galate, camptothcin, and 3,3'-diindolylmethane. More comprehensive information about lncRNA modulation via phytochemicals would be helpful for the administration of new herbal derivatives in cancer therapy. In this review, we describe the state-of-the-art and potential of phytochemicals as modulators of lncRNAs in different types of cancers.

Catechins-Modified Selenium-Doped Hydroxyapatite Nanomaterials for Improved Osteosarcoma Therapy Through Generation of Reactive Oxygen Species

Osteosarcoma is the most common bone cancer with limited therapeutic options. It can be treated by selenium-doped hydroxyapatite owing to its known antitumor potential. However, a high concentration of Se is toxic toward normal and stem cells whereas its low concentration cannot effectively remove cancer cells. Therefore, the current study was aimed to improve the anticancer activity of Se-HAp nanoparticles through catechins (CC) modification owing to their high cancer therapeutic value. The sequentially developed catechins modified Se-HAp nanocomposites (CC/Se-HAp) were characterized for various physico-chemical properties and antitumor activity. Structural analysis showed the synthesis of small rod-like single phase HAp nanoparticles (60 ± 15 nm), which effectively interacted with Se and catechins and formed agglomerated structures. TEM analysis showed the internalization and degradation of CC/Se-HAp nanomaterials within MNNG/HOS cells through a non-specific endocytosis process. Cell toxicity analysis showed that catechins modification improved the antitumor activity of Se-HAp nanocomposites by inducing apoptosis of human osteosarcoma MNNG/HOS cell lines, through generation of reactive oxygen species (ROS) which in turn activated the caspase-3 pathway, without significantly affecting the growth of human normal bone marrow stem cells (hBMSCs). qPCR and western blot analyses revealed that casp3, p53, and bax genes were significantly upregulated while cox-2 and PTK-2 were slightly downregulated as compared to control in CC/Se-HAp-treated MNNG/HOS cell lines. The current study of combining natural biomaterial (i.e., catechins) with Se and HAp, can prove to be an effective therapeutic approach for bone cancer therapy.

IGF1R predicts better survival in high-grade serous epithelial ovarian cancer patients and correlates with hCtr1 levels

Aim: To evaluate the potential of IGF1R as a prognostic marker for high-grade serous ovarian cancer (HGSOC) patients. Patients & methods: The expression levels of IGF1R and drug transporters (ABCB1, hCtr1) were measured longitudinally in chemo-naive and chemo-treated tumor samples from 19 HGSOC patients, and their correlation with the clinical outcome was examined. Results: IGF1R expression was significantly upregulated in treated tumor samples, which positively correlated with hCtr1 levels. Patients with metastatic tumors with IGF1R expression higher than median showed better overall survival (median not reached) and disease-free survival (26.7 months) than those with less than median expression (overall survival: 27.5 months [p = 0.029]; disease-free survival: 11.9 months [p = 0.014]). Conclusion: IGF1R prognosticates prolonged survival in HGSOC patients, possibly due to its positive correlation with hCtr1.

Long noncoding RNA NEAT1 promotes the growth of cervical cancer cells via sponging miR-9-5p

Evidence has accumulated demonstrating that long noncoding RNAs (lncRNAs) participate in the initiation and progression of cancers. In this study, we found that the lncRNA nuclear paraspeckle assembly transcript 1 (NEAT1) is significantly increased in both cervical cancer tissues and cell lines. Overexpression of NEAT1 promoted the proliferation and migration of cervical cancer cells. Molecular studies uncovered that NEAT1 functions as competitive endogenous RNA (ceRNA), binding the micro-RNA miR-9-5p and suppressing its expression. However, we consistently found that when NEAT1 was highly expressed, it attenuated the inhibitory effect of miR-9-5p on the expression of PTEN and POU2F1, which are the targets of miR-9-5p. Consistent with the negative regulation of NEAT1 on miR-9-5p, restoration of miR-9-5p inhibited the growth-promoting effects of NEAT1 on cervical cancer cells. Taken together, these results indicated that NEAT1 plays an important role in the regulation cervical cancer cell growth by targeting miR-9-5p. Our findings characterized the possible mechanism of NEAT1 in cervical cancer.

Silencing long non-coding RNA NEAT1 enhances the suppression of cell growth, invasion, and apoptosis of bladder cancer cells under cisplatin chemotherapy

It has been proven that NEAT1 as a long non-coding RNA (lncRNA) is highly expressed in bladder cancer (BC). Nevertheless, the oncogenic roles of NEAT1 in BC remain largely unknown. In the present study, we observed that the RNA level of NEAT1.1, one RNA variant of NEAT1, was reduced in cisplatin-sensitive T24 cells compared to cisplatin-resistant T24 (T24R) cells after both treated with cisplatin modulated through Wnt/β-catenin signaling pathway using RNA-seq. Furthermore, NEAT1.1 was knocked down within T24R cells and caused a phenotype of the compromised cell growth, invasion and enhanced apoptosis upon cisplatin treatment compared to untreated T24R cells. Finally, c-MYC, OCT4 and p53 were determined to contribute to the transcriptional regulation of NEAT1.1 under cisplatin using ChIP assay. Taken together, our results suggest that NEAT1.1 blocking can promote the effect of cisplatin for BC treatment.

Long non-coding RNA FLJ22763 is involved in the progression and prognosis of gastric cancer

Long noncoding RNAs (lncRNAs) play important roles in carcinogenesis. It is necessary to uncover the detailed pattern of comprehensive lncRNA expression in the genome during the development of gastric cancer (GC). We implemented lncRNA microarray analysis in 5 paired GC tissues to detect the lncRNA expression profile. Moreover, we set out to explore the biological function, clinical application and molecular basis of the aberrant lncRNA in GC. In addition, we used the high-throughput microarray to identify the target gene of the aberrant lncRNA. We found that FLJ22763, a novel lncRNA, had significantly lower expression in GC tissues. Decreased expression of FLJ22763 was positively correlated with a lower-level histological grade and the depth of invasion. The ectopic expression of lncRNA FLJ22763 significantly suppressed the biological malignant behavior of GC cells and inhibited xenograft tumor growth (both P < 0.001). Notably, FLJ22763 displayed a considerable predictive effect in the prognosis of GC (log-rank, P = 0.003). Furthermore, we found that FLJ22763 was negatively associated with ACLY, regulating the mRNA and protein levels of ACLY. Our findings suggested that FLJ22763 may act as a suppressor gene to regulate the expression of ACLY, and its down-expression may be an independent prognostic factor in patients with GC.

Epigallocatechin‑3‑gallate modulates long non‑coding RNA and mRNA expression profiles in lung cancer cells

(−)-Epigallocatechin-3-gallate (EGCG), a major constituent of green tea, is a potential anticancer agent, but the molecular mechanisms of its effects are not well-understood. The present study was conducted to examine the mechanism of EGCG in lung cancer cells. Alterations in long non-coding RNAs (lncRNAs) and mRNAs were investigated in lung cancer cells treated with EGCG by lncRNA microarray analysis. Furthermore, the functions and signaling pathways regulated by EGCG were predicted by bioinformatics analysis. A total of 960 lncRNAs and 1,434 mRNAs were significantly altered following EGCG treatment. These lncRNAs were distributed across nearly all human chromosomes and the mRNAs were involved in the cell cycle and the mitotic cell cycle process. Through a combination of microarray and bioinformatics analysis, 20 mRNAs predicted to serve a key role in the EGCG regulation were identified, and certain regulatory networks involving EGCG-regulated lncRNAs were predicted. In conclusion, EGCG affects the expression of various lncRNAs and mRNAs in the cells, therefore affecting cell functions. The results of the present study provide an insight into the mechanism of EGCG, which may be useful for therapeutic development.

Relations between approved platinum drugs and non-coding RNAs in mesothelioma

Malignant mesothelioma diseases feature an increasing risk due to their severe forms and their association with asbestos exposure. Platinum(II) complexes such as cisplatin and carboplatin are clinically approved for the therapy of mesothelioma often in combination with antimetabolites such as pemetrexed or gemcitabine. It was observed that pathogenic properties of mesothelioma cells and the response of mesothelioma tumors towards platinum-based drugs are strongly influenced by non-coding RNAs, in particular, by small microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). These non-coding RNAs controlled drug sensitivity and the development of tumor resistance towards platinum drugs. An overview of the interactions between platinum drugs and non-coding RNAs is given and the influence of non-coding RNAs on platinum drug efficacy in mesothelioma is discussed. Suitable non-coding RNA-modulating agents with potentially beneficial effects on cisplatin treatment of mesothelioma diseases are mentioned. The understanding of mesothelioma diseases concerning the interactions of non-coding RNAs and platinum drugs will optimize existing therapy schemes and pave the way to new treatment options in future.

Interplay of non-coding RNAs and approved antimetabolites such as gemcitabine and pemetrexed in mesothelioma

Gemcitabine and pemetrexed are clinically approved antimetabolites for the therapy of mesothelioma diseases. These drugs are often applied in combination with platinum complexes and other drugs. The activity of antimetabolites depended on the expression levels of certain non-coding RNAs, in particular, of small microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). The development of tumor resistance towards antimetabolites was regulated by non-coding RNAs. An overview of the interplay between gemcitabine/pemetrexed antimetabolites and non-coding RNAs in mesothelioma is provided. Further to this, various non-coding RNA-modulating agents are discussed which displayed positive effects on gemcitabine or pemetrexed treatment of mesothelioma diseases. A detailed knowledge of the connections of non-coding RNAs with antimetabolites will be constructive for the design of improved therapies in future.

LncRNA NEAT1 promotes the tumorigenesis of colorectal cancer by sponging miR-193a-3p

Objectives

LncRNA nuclear‐enriched abundant transcript 1 (NEAT1) participates in the development and progression of multiple malignancies. However, the molecular mechanism by which NEAT1 contributes to colorectal cancer (CRC) remains unclear.

Methods

The association between lncRNA NEAT1 expression and clinicopathological characteristics and prognosis in patients with CRC was analysed by TCGA RNA‐sequencing data. MTT, colony formation, flow cytometry, transwell assays and a xenograft tumour model were used to assess the functions of NEAT1. Bioinformatics and spearman correlation analysis were used to identify the NEAT1‐specific binding with miRNAs, and luciferase gene report and RIP assays were performed to confirm the interaction between miR‐193a‐3p (miR‐193a) and NEAT1 in CRC cells.

Results

Upregulation of NEAT1 expression was significantly correlated with TNM stage, poor survival and tumour recurrence in patients with CRC, and acted as an independent prognostic factor for tumour recurrence. Knockdown of NEAT1 suppressed cell proliferation, colony formation abilities and invasive potential and induced cell apoptosis, but overexpression of NEAT1 reversed these effects. Furthermore, NEAT1 was confirmed to act as a sponge of miR‐193a, and knockdown of NEAT1 attenuated miR‐193a inhibitor‐induced tumour promoting effects and L17RD expression in CRC cells. miR‐193a harboured negative correlation with NEAT1 and IL17RD expression in CRC specimens. In vivo experiment further validated the inhibitory effects of NEAT1 knockdown on xenograft tumour growth.

Conclusion

Our findings demonstrate that lncRNA NEAT1 acts as an oncogenic role in CRC cells by sponging miR‐193a and may represent a potential marker for CRC patients.

MicroRNA-98-5p inhibits proliferation and metastasis in non-small cell lung cancer by targeting TGFBR1

MicroRNAs (miRNAs or miRs) have recently emerged as key regulators of various types of cancer, including non‑small cell lung cancer (NSCLC). The disrupted expression of miRNAs is associated with tumorigenesis and metastasis; however, the underlying mechanisms remain unclear. In this study, we demonstrate that miR‑98‑5p is downregulated in NSCLC and that miR‑98‑5p deficiency is associated with an advanced clinical stage and metastasis. A dual‑luciferase reporter assay was performed to confirm that transforming growth factor beta receptor 1 (TGFBR1), a key stimulator of tumor proliferation and metastasis, was a direct target of miR‑98‑5p. miR‑98‑5p overexpression resulted in the downregulation of TGFBR1 and the suppression of the viability, proliferation, migration and invasion of A549 and H1299 cells. Furthermore, miR‑98‑5p was demonstrated to be an efficient suppressor of tumor growth in an A549 subcutaneous xenograft tumor mouse model. Finally, miR‑98‑5p overexpression exerted a significant anti‑metastatic effect in a mouse model of pulmonary metastasis. On the whole, the results of the present study suggest that miR‑98‑5p/TGFBR1 may serve as promising targets for NSCLC therapy.

Non-coding RNA NEAT1/miR-214-3p contribute to doxorubicin resistance of urothelial bladder cancer preliminary through the Wnt/β-catenin pathway

BACKGROUND

Urothelial bladder cancer (UBC) is one of the most lethal urological malignancies in the world. Patients with UBC are routinely given chemotherapy which results in a median survival of 12-15 months. Nuclear-enriched abundant transcript 1 (NEAT1) functions as an oncogene and could be used as a therapeutic target for human UBC. However, the involvement of NEAT1 in doxorubicin (DOX) resistance of UBC has been poorly demonstrated.

METHODS

Quantitative Real-time PCR (qRT-PCR) was used to detect the expression levels of NEAT1 and miR-214-3p in UBC tissues and cells. Bioinformatics prediction, RNA pull-down and qRT-PCR were used to assay the regulation manner of NEAT1 and miR-214-3p. Loss/gain function of NEAT1 and miR-214-3p together with western blot, drug resistance assay and flow cytometry were used to explore the influence of NEAT1 in DOX resistance was correlative with miR-214-3p. Finally, luciferase assay system was applied to determine the Wnt/β-catenin signal activity.

RESULTS

NEAT1 was upregulated and miR-214-3p was downregulated in DOX-resistant UBC tissues and cells. NEAT1 knockdown inhibited J82 and T24 cells to DOX chemosensitivity by negatively regulating miR-214-3p expression. NEAT1/miR-214-3p contributed to DOX resistance of UBC preliminary through the Wnt/β-catenin pathway.

CONCLUSION

NEAT1 contributed to DOX resistance of UBC through the Wnt/β-catenin pathway partly by negatively regulating miR-214-3p expression. Our findings will provide a promising ncRNA targeted therapeutic strategy for UBC with DOX resistance.

Long Non-Coding RNAs as New Master Regulators of Resistance to Systemic Treatments in Breast Cancer

Predicting response to systemic treatments in breast cancer (BC) patients is an urgent, yet still unattained health aim. Easily detectable molecules such as long non-coding RNAs (lncRNAs) are the ideal biomarkers when they act as master regulators of many resistance mechanisms, or of mechanisms that are common to more than one treatment. These kinds of markers are pivotal in quasi-personalized treatment selection, and consequently, in improvement of outcome prediction. In order to provide a better approach to understanding development of disease and resistance to treatments, we reviewed current literature searching for lncRNA-associated systemic BC treatments including endocrine therapies, aromatase inhibitors, selective estrogen receptor modulators (SERMs), trastuzumab, paclitaxel, docetaxel, 5-fluorouracil (5-FU), anthracyclines, and cisplatin. We found that the engagement of lncRNAs in resistance is well described, and that lncRNAs such as urotelial carcinoma-associated 1 (UCA1) and regulator of reprogramming (ROR) are indeed involved in multiple resistance mechanisms, which offers tantalizing perspectives for wide usage of lncRNAs as treatment resistance biomarkers. Thus, we propose this work as the foundation for a wide landscape of functions and mechanisms that link more lncRNAs to resistance to current and new treatments in years of research to come.

Long noncoding RNA NEAT1, regulated by LIN28B, promotes cell proliferation and migration through sponging miR-506 in high-grade serous ovarian cancer

The aberrant expression of long noncoding RNAs (lncRNAs) has been reported frequently in specific cancers, including high-grade serous ovarian cancer (HGSOC). The purpose of the present study was to explore the clinical significance and underlying mechanisms of a significantly dysregulated lncRNA (NEAT1) in HGSOC. Our results showed that elevated NEAT1 expression in human HGSOC specimens correlated with a poor prognosis. Functional experiments demonstrated that knockdown of NEAT1 significantly prohibited ovarian cancer cell proliferation and invasion in vitro and restrained tumor growth in vivo. LIN28B was identified by bioinformatics analysis along with experimental evidence as a direct actor that enhanced NEAT1 stability. A rescue functional assay confirmed that the LIN28B/NEAT1 axis contributed to oncogenic functions in ovarian cancer cells. Moreover, gene expression profile data and dual luciferase reporter assay results demonstrated that NEAT1 functioned as a competing endogenous RNA (ceRNA) for miR-506 to promote cell proliferation and migration. Taken together, our results showed that NEAT1, stabilized by LIN28B, promoted HGSOC progression by sponging miR-506. Thus, NEAT1 can be regarded as a vital diagnostic biomarker for HGSOC and a therapeutic target.

Systematic identification of non-coding pharmacogenomic landscape in cancer

Emerging evidence has shown long non-coding RNAs (lncRNAs) play important roles in cancer drug response. Here we report a lncRNA pharmacogenomic landscape by integrating multi-dimensional genomic data of 1005 cancer cell lines and drug response data of 265 anti-cancer compounds. Using Elastic Net (EN) regression, our analysis identifies 27,341 lncRNA-drug predictive pairs. We validate the robustness of the lncRNA EN-models using two independent cancer pharmacogenomic datasets. By applying lncRNA EN-models of 49 FDA approved drugs to the 5605 tumor samples from 21 cancer types, we show that cancer cell line based lncRNA EN-models can predict therapeutic outcome in cancer patients. Further lncRNA-pathway co-expression analysis suggests lncRNAs may regulate drug response through drug-metabolism or drug-target pathways. Finally, we experimentally validate that EPIC1, the top predictive lncRNA for the Bromodomain and Extra-Terminal motif (BET) inhibitors, strongly promotes iBET762 and JQ-1 resistance through activating MYC transcriptional activity.

Epigallocatechin-3-gallate inhibited cancer stem cell-like properties by targeting hsa-mir-485-5p/RXRα in lung cancer

Non-small-cell lung cancer (NSCLC) appears to be a significant threat to public health worldwide. MicroRNAs have been identified as significant regulators for the development of NSCLC. Previous reports have suggested that hsa-mir-485-5p is dysregulated in various cancers. RXRα, as a kind of nuclear receptor, is an effective target of cancer treatment. Cancer stem cells (CSCs) are recognized as the main cause for tumor metastasis, recurrence, and chemotherapy resistance. However, the mechanism by which hsa-mir-485-5p and RXRα modulate CSCs in NSCLC remains unknown. Here, we found that hsa-mir-485-5p was decreased in serum samples from patients with NSCLC and NSCLC cells. Meanwhile, epigallocatechin-3-gallate (EGCG), an effective anticancer compound extracted from green tea, can enhance hsa-mir-485-5p expression. Hsa-mir-485-5p mimics markedly inhibited NSCLC cell growth and induced cell apoptosis. However, inhibition of hsa-mir-485-5p significantly enriched CSC-like traits. Moreover, bioinformatics analysis predicted the binding correlation between hsa-mir-485-5p and RXRα, which was confirmed by a dual-luciferase reporter assay. We observed that RXRα was increased in NSCLC and EGCG could inhibit RXRα levels dose dependently. In addition, RXRα upregulation or activation expanded the CSC-like properties of NSCLC cells, whereas RXRα inhibition or inactivation could exert a reverse phenomenon. Consistently, in vivo experiments also validated that EGCG could repress the CSC-like characteristics by modulating the hsa-mir-485-5p/RXRα axis. Our findings may reveal a novel molecular mechanism for the treatment of NSCLC.

Role of long non-coding RNA in drug resistance in non-small cell lung cancer

Lung cancer is the leading cause of cancer-associated death, and non-small cell lung cancer (NSCLC) accounts for 85% of all lung cancer cases. Many drugs have been used to treat NSCLC in order to improve patient prognosis. Platinum-based chemotherapy is the first-line treatment for locally advanced or metastatic patients. For patients with activating EGFR mutations, tyrosine kinase inhibitors are the best treatment choice. NSCLC initially exhibits an excellent response to treatment; however, acquired resistance has been observed in many patients, leading to ineffective treatment. Clinical resistance is an impediment in the treatment of patients with advanced NSCLC. Many sequencing technologies have shown that long non-coding RNA (lncRNA) is expressed differently between drug-resistant and drug-sensitive lung cancer cells. We review the literature on lncRNA in drug resistance of NSCLC. The aim of this review is to gain insight into the molecular mechanisms of drug resistance, mainly focusing on the role of lncRNA in NSCLC.

Epigallocatechin-3-O-gallate, the main green tea component, is toxic to Saccharomyces cerevisiae cells lacking the Fet3/Ftr1

Epigallocatechin-3-O-gallate (EGCG), the main green tea component, is intensively studied for its anti-oxidant, anti-inflammatory, anti-microbial and anti-cancer effects. In the present study, a screen on a Saccharomyces cerevisiae gene deletion library was performed to identify conditions under which EGCG had deleterious rather than beneficial effects. Two genes were identified whose deletion resulted in sensitivity to EGCG: FET3 and FTR1, encoding the components of the Fet3/Ftr1 high-affinity iron uptake system, also involved in Cu(I)/Cu(II) balance on the surface of yeast cells. The presence of EGCG in the growth medium induced the production of Cu(I), with deleterious effects on fet3Δ and ftr1Δ cells. Additionally, when combined, physiological surpluses of Cu(II) and EGCG acted in synergy not only against fet3Δ and ftr1Δ, but also against wild type cells, by generating surplus Cu(I) in the growth medium. The results imply that caution should be taken when combining EGCG-rich beverages/nutraceuticals with copper-rich foods.