WW domain binding protein 5 induces multidrug resistance of small cell lung cancer under the regulation of miR-335 through the Hippo pathway

Deciphering the role of Hippo pathway in lung cancer

Hippo pathway has been initially recognized as a regulatory mechanism for modulation of organ size in fruitfly. Subsequently, its involvement in the regulation of homeostasis and tumorigenesis has been identified. This pathway contains some tumor suppressor genes such as hippo (hpo) and warts (wts), as well as a number of oncogenic ones such as yorkie (yki). Recent studies have shown participation of Hippo pathway in the lung carcinogenesis. This pathway can affect lung cancer via different mechanisms. The interaction between some miRNAs and Hippo pathway is a possible mechanism for carcinogenic processes. Moreover, some other types of non-coding RNAs including PVT1, SFTA1P, NSCLCAT1 and circ_0067741 are implicated in this process. Besides, anti-cancer effects of gallic acid, icotinib hydrochloride, curcumin, ginsenoside Rg3, cryptotanshinone, nitidine chloride, cucurbitacin E, erlotinib, verteporfin, sophoridine, cisplatin and verteporfin in lung cancer are mediated through modulation of Hippo pathway. Here, we summarize the results of recent studies that investigated the role of Hippo signaling in the progression of lung cancer, the impact of non-coding RNAs on this pathway and the effects of anti-cancer agents on Hippo signaling in the context of lung cancer.

MicroRNAs Involved in Small-cell Lung Cancer as Possible Agents for Treatment and Identification of New Targets

Small-cell lung cancer, a neuro-endocrine type of lung cancers, responds very well to chemotherapy-based agents. However, a high frequency of relapse due to adaptive resistance is observed. Immunotherapy-based treatments with checkpoint inhibitors has resulted in improvement of treatment but the responses are not as impressive as in other types of tumor. Therefore, identification of new targets and treatment modalities is an important issue. After searching the literature, we identified eight down-regulated microRNAs involved in radiation- and chemotherapy-induced resistance, as well as three up-regulated and four down-regulated miRNAs with impacts on proliferation, invasion and apoptosis of small-cell lung cancer cells in vitro. Furthermore, one up-regulated and four down-regulated microRNAs with in vivo activity in SCLC cell xenografts were identified. The identified microRNAs are candidates for inhibition or reconstitution therapy. The corresponding targets are candidates for inhibition or functional reconstitution with antibody-based moieties or small molecules.

New Insights into the Clinical Implications of Yes-Associated Protein in Lung Cancer: Roles in Drug Resistance, Tumor Immunity, Autophagy, and Organoid Development

Simple Summary

Innovative advancements in lung cancer treatment have developed over the past decade with the advent of targeted and immune therapies. Yes-associated protein (YAP), an effector of the Hippo pathway, promotes the resistance of these targeted drugs and modulates tumor immunity in lung cancer. YAP is involved in autophagy in lung cancer and plays a prominent role in forming the tubular structure in lung organoids and alveolar differentiation. In this review, we discuss the central roles of YAP in lung cancer and present YAP as a novel target for treating resistance to targeted therapies and immunotherapies in lung cancer.

Abstract

Despite significant innovations in lung cancer treatment, such as targeted therapy and immunotherapy, lung cancer is still the principal cause of cancer-associated death. Novel strategies to overcome drug resistance and inhibit metastasis in cancer are urgently needed. The Hippo pathway and its effector, Yes-associated protein (YAP), play crucial roles in lung development and alveolar differentiation. YAP is known to mediate mechanotransduction, an important process in lung homeostasis and fibrosis. In lung cancer, YAP promotes metastasis and confers resistance against chemotherapeutic drugs and targeted agents. Recent studies revealed that YAP directly controls the expression of programmed death-ligand 1 (PD-L1) and modulates the tumor microenvironment (TME). YAP not only has a profound relationship with autophagy in lung cancer but also controls alveolar differentiation, and is responsible for tubular structure formation in lung organoids. In this review, we discuss the various roles and clinical implications of YAP in lung cancer and propose that targeting YAP can be a promising strategy for treating lung cancer.

Exosomal miR-92b-3p Promotes Chemoresistance of Small Cell Lung Cancer Through the PTEN/AKT Pathway

Resistance to first-line chemotherapy drugs has become an obstacle to improving the clinical prognosis of patients with small cell lung cancer (SCLC). Exosomal microRNAs have been shown to play pro- and anti-chemoresistant roles in various cancers, but their role in SCLC chemoresistance has never been explored. In this study, we observed that the expression of exosomal miR-92b-3p was significantly increased in patients who developed chemoresistance. Luciferase reporter analysis confirmed that PTEN was a target gene of miR-92b-3p. The PTEN/AKT regulatory network was related to miR-92b-3p-mediated cell migration and chemoresistance in vitro and in vivo in SCLC. Importantly, exosomes isolated from the conditioned medium of SBC-3 cells overexpressing miR-92b-3p could promote SCLC chemoresistance and cell migration. Furthermore, we found that plasma miR-92b-3p levels were significantly higher in patients with chemoresistant SCLC than in those with chemosensitive SCLC, but the levels were down-regulated in patients who achieved remission. Kaplan–Meier analysis showed that SCLC patients with high miR-92b-3p expression were associated with shorter progression-free survival. Overall, our results suggested that exosomal miR-92b-3p is a potential dynamic biomarker to monitor chemoresistance in SCLC and represents a promising therapeutic target for chemoresistant SCLC.

Functions and Targets of miR-335 in Cancer

MicroRNAs (miRNAs) are small non-coding RNAs (18~25 nt in length) that act as master regulators of eukaryotic gene expression. They might play an oncogenic or tumor-suppressive role in multiple cancers. In recent decades, several studies have focused on the functions and mechanisms of miR-335 in cancer. The expression level of miR-335 in tissues and cells varies with cancer types, and miR-335 has been proposed as a potential biomarker for the prognosis of cancer. Besides, miR-335 may serve as an oncogene or tumor suppressor via regulating different targets or pathways in tumor initiation, development, and metastasis. Furthermore, miR-335 also influences tumor microenvironment and drug sensitivity. MiR-335 is regulated by various factors such as lncRNAs and microRNAs. In this review, we reveal the functions and targets of miR-335 in various cancers and its potential application as a possible biomarker in prognostic judgment and treatment of malignant tumors.

Role of microRNAs in regulating cell proliferation, metastasis and chemoresistance and their applications as cancer biomarkers in small cell lung cancer

Small cell lung cancer (SCLC), a smoking-related highly aggressive neuroendocrine cancer, is characterized by rapid cell proliferation, early metastatic dissemination, and early relapse due to chemoresistance to first-line platinum-doublet chemotherapy. Genomically, SCLC tumors show nearly universal loss of TP53 and RB1 tumor suppressor genes, while gene expression signature classifies them into 4 distinct subgroups based on the expression patterns of lineage transcription factors - ASCL1/ASH1, NEUROD1, YAP-1, and POU2F3. Due to the lack of targetable molecular alterations and clinically useful diagnostic, prognostic and predictive biomarker, there is insignificant progress in the therapeutic management of SCLC patients. Numerous studies have shown a significant involvement of non-coding RNAs in the regulation of cell proliferation, invasion and migration, apoptosis, metastasis, and chemoresistance in various human cancers. In this review, we comprehensively discuss the role of microRNAs (miRNAs) in regulating the aforementioned biological process in SCLC. For this, we searched the scientific literature and selected studies that have evaluated the role of miRNAs in the disease pathogenesis or as a cancer biomarker in SCLC. Our review suggests that several miRNAs are involved in the pathogenesis of SCLC mainly by regulating cell proliferation, metastasis, and chemoresistance. Few studies have also demonstrated the clinical utility of miRNAs in monitoring response to chemotherapy as well as in predicting survival outcomes. However, more in-depth mechanistic studies utilizing in vivo models and multicentric studies with larger patient cohorts are needed before the applications of miRNAs as therapeutic targets or as biomarkers are translated from the laboratory into clinics.

Exosomal miR-335 derived from mature dendritic cells enhanced mesenchymal stem cell-mediated bone regeneration of bone defects in athymic rats

BACKGROUND

Transplantation of bone marrow-derived mesenchymal stem cells (BM-MSCs) embedded in a bio-compatible matrix has been demonstrated as a promising strategy for the treatment of bone defects. This study was designed to explore the effect and mechanism of exosomes derived from mature dendritic cells (mDC-Exo) on the BM-MSCs-mediated bone regeneration using the matrix support in an athymic rat model of femoral bone defect.

METHODS

The BM-MSCs were isolated from rats and incubated with osteoblast induction medium, exosomes derived from immature DCs (imDC-Exo), mDC-Exo, and miR-335-deficient mDC-Exo. BM-MSCs treated without or with mDC-Exo were embedded in a bio-compatible matrix (Orthoss®) and then implanted into the femoral bone defect of athymic rats.

RESULTS

mDC-Exo promoted the proliferation and osteogenic differentiation of BM-MSCs by transferring miR-335. Mechanistically, exosomal miR-335 inhibited Hippo signaling by targeting large tongue suppressor kinase 1 (LATS1) and thus promoted the proliferation and osteogenic differentiation of BM-MSCs. Animal experiments showed that mDC-Exo enhanced BM-MSCs-mediated bone regeneration after bone defect, and this effect was abrogated when miR-335 expression was inhibited in mDC-Exo.

CONCLUSION

mDC-Exo promoted osteogenic differentiation of BM-MSCs and enhanced BM-MSCs-mediated bone regeneration after femoral bone defect in athymic rats by transferring miR-335.

Evaluation of Hippo Pathway and CD133 in Radiation Resistance in Small-Cell Lung Cancer

Although the Hippo pathway and CD133 have been reported to play pertinent roles in a variety of cancer, knowledge about their contribution to radiation resistance in small-cell lung cancer (SCLC) is limited. In this first-of-a-kind study, we have reported the expression of key Hippo pathway proteins in SCLC patients by immunohistochemical staining. We assessed the involvement of yes-associated protein 1 (YAP1) in radiation resistance by Cell Counting Kit-8 (CCK-8) and flow cytometry. In addition, we analysed the impact of CD133 on radiotherapy for SCLC. The mammalian Ste20-like serine/threonine kinase 2(MST2), pMST2, and pYAP1 in the Hippo pathway were not significantly associated with the disease stage and survival time in patients with SCLC. However, the pYAP1 expression showed some significance in the "YAP/TAZ subgroup" of SCLC patients. The proportion of CD133 in the SCLC cells was controlled by the YAP1 expression. The CD133 and YAP1 levels were significantly correlation with each other in tissues of SCLC patients. We sorted and isolated the CD133+ and CD133-cells in H69 and found that the cell surface glycoprotein may be associated with the radiation resistance of SCLC.In summary, we have firstly reported the expression of key Hippo pathway proteins in SCLC patients. Furthermore, we also identified that CD133 may be controlled by the expression of YAP1 in the Hippo pathway and that CD133 may be associated with the radiation resistance of SCLC.

Prognostic immunohistochemical markers for small cell lung cancer: A review

BACKGROUND

Small Cell Lung Cancer (SCLC) is one of the most aggressive thoracic malignancies and has been very challenging in developing personalized medicine. While immunohistochemistry (IHC) markers have established role in pathology diagnosis of SCLC, it is particularly important to apply early and simple methods to effectively determine the prognosis. This study aimed to review and identify prognostic protein markers that have potential to be incorporated into clinical care for SCLC.

METHODS

we systematically reviewed PubMed, Embase, Web of Science and Cochrane Library until October 19th, 2019 that reported prognostic IHC markers in SCLC. In this review, we focused on markers evaluated in at least two independent studies to compile the most forthcoming prognostic markers.

RESULTS

According to their function in the tumor, including proliferation-related markers, growth suppression-related markers, invasion- and metastasis-related markers, apoptosis-related markers, angiogenesis-related markers, immune regulation-related markers. Extensive reports into informative tables based on sufficiencies of evidence were summarized as some easy-to-use literature reservoirs for further referring.

CONCLUSIONS

Strong evidence supports that the 24 emerging markers or their combinations may be useful in predicting prognosis, helping personalized therapy decision-making for SCLC patients.

Regulation of Hippo signaling pathway in cancer: A MicroRNA perspective

Recent studies have suggested that Hippo signaling is not only involved in controlling organ size in Drosophila but can also regulate cell proliferation, tissue homeostasis, differentiation, apoptosis and regeneration. Any dysregulation of Hippo signaling, especially the hyper activation of its downstream effectors YAP/TAZ, can lead to uncontrolled cell proliferation and malignant transformation. In majority of cancers, expression of YAP/TAZ is extremely high and this increased expression of YAP/TAZ has been shown to be an independent predictor of prognosis and indicator of increased cell proliferation, metastasis and poor survival. In this review, we have summarized the most recent findings about the cross talk of Hippo signaling pathway with other signaling pathways and its regulation by different miRNAs in various cancer types. Recent evidence has suggested that Hippo pathway is also involved in mediating the resistance of different cancer cells to chemotherapeutic drugs and in a few cancer types, this is brought about by regulating miRNAs. Therefore, the delineation of the underlying mechanisms regulating the chemotherapeutic resistance might help in developing better treatment options. This review has attempted to provide an overview of different drugs/options which can be utilized to target oncogenic YAP/TAZ proteins for therapeutic interventions.

The Role of Photoactivated and Non-Photoactivated Verteporfin on Tumor

Verteporfin (VP) has long been clinically used to treat age-related macular degeneration (AMD) through photodynamic therapy (PDT). Recent studies have reported a significant anti-tumor effect of VP as well. Yes-associated protein (YAP) is a pro-tumorigenic factor that is aberrantly expressed in various cancers and is a central effector of the Hippo signaling pathway that regulates organ size and tumorigenesis. VP can inhibit YAP without photoactivation, along with suppressing autophagy, and downregulating germinal center kinase-like kinase (GLK) and STE20/SPS1-related proline/alanine-rich kinase (SPAK). In addition, VP can induce mitochondrial damage and increase the production of reactive oxygen species (ROS) upon photoactivation, and is an effective photosensitizer (PS) in anti-tumor PDT. We have reviewed the direct and adjuvant therapeutic action of VP as a PS, and its YAP/TEA domain (TEAD)-dependent and independent pharmacological effects in the absence of light activation against cancer cells and solid tumors. Based on the present evidence, VP may be repositioned as a promising anti-cancer chemotherapeutic and adjuvant drug.

Vitamin D3 analogue facilitates epithelial wound healing through promoting epithelial-mesenchymal transition via the Hippo pathway

BACKGROUND

Wound healing is a complex physiological process that is crucial for reestablishing the epithelial barrier following injury.

OBJECTIVE

The aim of this study was to demonstrate the efficacy of calcipotriol, a synthetic vitamin D3 analogue, in wound healing in an acute mice wound model.

METHODS

An excision wound model was established in mice, and the wound healing activity of calcipotriol was evaluated. Human keratinocyte cell lines, HaCaT and NHEK, were utilized in in vitro skin wound healing model. Cytokine expression levels were measured by real-time PCR and ELISA assay. The expression of epithelial-mesenchymal transition (EMT)-associated molecules and the phosphorylation of Yes-associated protein (YAP) was determined by western blotting.

RESULTS

The increase in re-epithelialization by calcipotriol treatment early in the wound was associated with the EMT process. A scratch assay using HaCaT and NHEK cells also showed that calcipotriol administration resulted in effective wound closure. We demonstrated that calcipotriol promoted keratinocyte migration by interfering with the Hippo pathway. Calcipotriol-mediated enhancement of cell migration is related to downregulated phosphorylation of YAP and increased levels of YAP and PDZ-binding motif (TAZ). Mechanistically, we defined that calcipotriol facilitated the crosstalk between the YAP/TAZ and TGF-β/Smad signaling pathways, eliciting EMT in keratinocytes during the wound healing process.

CONCLUSIONS

These results suggest that the positive effect of calcipotriol on keratinocyte migration is mediated by the induction of EMT via the regulation of Hippo pathway, which promotes the acceleration of wound closure.

Interaction of non-coding RNAs and Hippo signaling: Implications for tumorigenesis

Hippo signaling is an evolutionarily conserved pathway that controls organ size by regulating cell proliferation, apoptosis, and stem cell self-renewal by "turning off" or "turning on" the kinase cascade chain reaction to manipulate the expression of downstream genes. Dysregulation of the Hippo pathway contributes to cancer development and metastasis. Emerging evidence has revealed new insights into tumorigenesis through the interplay between the Hippo pathway and non-coding RNAs (ncRNAs), especially microRNA, long non-coding RNA and circular RNA. Here, we reviewed the interactions between the Hippo pathway and ncRNAs and their implication for a variety of tumor-promoting or tumor-repressing effects. These interactions have the potential to serve as cancer biomarkers and therapeutic targets in clinical applications.

Characterization of microRNA profiles in the mammary gland tissue of dairy goats at the late lactation, dry period and late gestation stages

MicroRNAs (miRNAs) play an important role in regulating mammary gland development and lactation. We previously analyzed miRNA expression profiles in Laoshan dairy goat mammary glands at the early (20 d postpartum), peak (90 d postpartum) and late lactation (210 d postpartum) stages. To further enrich and clarify the miRNA expression profiles during the lactation physiological cycle, we sequenced miRNAs in the mammary gland tissues of Laoshan dairy goats at three newly selected stages: the late lactation (240 d postpartum), dry period (300 d postpartum) and late gestation (140 d after mating) stages. We obtained 4038 miRNAs and 385 important miRNA families, including mir-10, let-7 and mir-9. We also identified 754 differentially expressed miRNAs in the mammary gland tissue at the 3 different stages and 6 groups of miRNA clusters that had unique expression patterns. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that GO terms such as mammary gland development (GO:0030879) and mammary gland morphogenesis (GO:0060443) and important signaling pathways, including the insulin signaling pathway (chx04910), hippo signaling pathway (chx04390) and estrogen signaling pathway (chx04915), were enriched. We screened miRNAs and potential target genes that may be involved in the regulation of lactation, mammary gland growth and differentiation, cell apoptosis, and substance transport and synthesis and detected the expression patterns of important genes at the three stages. These miRNAs and critical target genes may be important factors for mammary gland development and lactation regulation and potentially valuable molecular markers, which may provide a theoretical reference for further investigation of mammary gland physiology.

Mechanisms of drugs-resistance in small cell lung cancer: DNA-related, RNA-related, apoptosis-related, drug accumulation and metabolism procedure

Small-cell lung cancer (SCLC), the highest malignant cancer amongst different types of lung cancer, has the feature of lower differentiation, rapid growth, and poor survival rate. Despite the dramatically initial sensitivity of SCLC to various types of treatment methods, including chemotherapy, radiotherapy and immunotherapy, the emergence of drugs-resistance is still a grandly clinical challenge. Therefore, in order to improve the prognosis and develop new therapeutic approaches, having a better understanding of the complex mechanisms of resistance in SCLC is of great clinical significance. This review summarized recent advances in understanding of multiple mechanisms which are involved in the resistance during SCLC treatment, including DNA-related process, RNA-related process, apoptosis-related mechanism, and the process of drug accumulation and metabolism.

High WBP5 expression correlates with elevation of HOX genes levels and is associated with inferior survival in patients with acute myeloid leukaemia

WW domain binding protein 5 (WBP5), also known as Transcriptional Elongation Factor A like 9 (TCEAL9) has been proposed as a candidate oncogene for human colorectal cancers with microsatellite instability and as a predictive indicator of small cell lung cancers. Furthermore, several independent studies have proposed WBP5, and its association with Wilms Tumor-1 (WT1) expression, as part of a gene expression-based risk score for predicting survival and clinical outcome in patients with Acute Myeloid Leukaemia (AML). To date, the prognostic significance of the sole WBP5 expression and its impact on the survival outcome in AML patients remains largely understudied. In the present study, we have made use of publicly available patient expression arrays and have developed an unbiased approach to classify AML patients into low versus high WBP5 expressers and to balance them for known mutations and cytogenetic findings. Interestingly, we found that patients characterized by high WBP5 expression displayed inferior overall and event-free survival rates. Notably, gene expression profiling showed that patients with high WBP5 had elevated expression of several HOX cluster genes, such as HOXA5, HOXA7, HOXA9 and HOXA10, and several of their partner proteins, such as MEIS1 and FOXC1, which have been demonstrated to be causative for AML. Taken together, our data suggest that WBP5 expression level could serve as an indicator for prognosis and survival outcome in patients with AML.

Clinicopathological and Prognostic Significance of WW Domain Binding Protein 5 Expression in Papillary Thyroid Carcinoma

Objectives

Many patients with papillary thyroid cancer (PTC) have a high recurrence risk and poor prognosis, and the main obstacle to the clinical diagnosis and treatment of PTC is lack of effective predictive molecular markers. The purpose of this study was to investigate the clinicopathological and prognostic implications of WW domain binding protein 5 (WBP5) expression in PTC.

Materials and Methods

Immunohistochemistry of WBP5 was performed using tissue microarrays of 131 patients with PTC who underwent surgery during January 2006 and January 2010 in the Zhejiang Cancer Hospital. Statistical analyses were conducted to evaluate the association between WBP5 expression and the clinicopathological features and to analyze the disease-free survival (DFS) and prognostic factors.

Results and Conclusion

The positive expression rate of WBP5 in PTC and the adjacent normal tissues was 42.75% (56/131) and 45.45% (10/22), respectively. WBP5 expression was significantly correlated with bilaterality, capsule invasion, and N-stage, and it was a favorable factor of DFS. Moreover, patients with a high WBP5 expression exhibited reduced risk of disease recurrence compared with that in patients with low WBP5 expression in the univariate analysis, whereas the multivariate analysis suggested that WBP5 was not an independent prognostic factor. Our results indicate that WBP5 might be a favorable prognosis indicator of PTC.

Defined factors to reactivate cell cycle activity in adult mouse cardiomyocytes

Adult mammalian cardiomyocytes exit the cell cycle during the neonatal period, commensurate with the loss of regenerative capacity in adult mammalian hearts. We established conditions for long-term culture of adult mouse cardiomyocytes that are genetically labeled with fluorescence. This technique permits reliable analyses of proliferation of pre-existing cardiomyocytes without complications from cardiomyocyte marker expression loss due to dedifferentiation or significant contribution from cardiac progenitor cell expansion and differentiation in culture. Using this system, we took a candidate gene approach to screen for fetal-specific proliferative gene programs that can induce proliferation of adult mouse cardiomyocytes. Using pooled gene delivery and subtractive gene elimination, we identified a novel functional interaction between E2f Transcription Factor 2 (E2f2) and Brain Expressed X-Linked (Bex)/Transcription elongation factor A-like (Tceal) superfamily members Bex1 and Tceal8. Specifically, Bex1 and Tceal8 both preserved cell viability during E2f2-induced cell cycle re-entry. Although Tceal8 inhibited E2f2-induced S-phase re-entry, Bex1 facilitated DNA synthesis while inhibiting cell death. In sum, our study provides a valuable method for adult cardiomyocyte proliferation research and suggests that Bex family proteins may function in modulating cell proliferation and death decisions during cardiomyocyte development and maturation.

YAP1 promotes multidrug resistance of small cell lung cancer by CD74-related signaling pathways

BACKGROUND

Our previous research found that YAP1 may have a role in multidrug resistance (MDR) in small cell lung cancer (SCLC). However, its underlying mechanism is unknown.

METHODS

In this study, we investigated the expression of YAP1 using immunohistochemical staining and assessed the relationship between the expression of YAP1 and overall survival in patients with SCLC. We established H69 stable cell lines that overexpressed constitutively active YAP1 and H446 stable cell lines that dominate negative YAP1. We conducted CCK-8, flow cytometric analysis, and in vivo chemosensitivity experiments to evaluate the function of YAP1 in drug sensitivity apoptosis in vitro and in vivo.

RESULTS

The results indicated that patients with high YAP1 expression have shorter survival rates and more advanced disease stage than those with low YAP1 expression. YAP1 may induce MDR by inhibiting the apoptosis of SCLC. YAP1 induced MDR when YAP1 was hyperactivated, and drug sensitivity increased when YAP1 was inhibited in vitro and in vivo. CD74 was significantly correlated with YAP1 in SCLC samples. Inhibition of CD74 using ISO-1 increased drug sensitivity significantly.

CONCLUSIONS

The expression of YAP1 is significantly correlated with overall survival and disease stage in patients with SCLC. YAP1 may play an important role in these patients. We were the first to report that YAP1 can induce MDR in SCLC in vitro and in vivo. CD74 may be involved in YAP1-induced MDR.

Current Smoking is Associated with Decreased Expression of miR-335-5p in Parenchymal Lung Fibroblasts

Cigarette smoking causes lung inflammation and tissue damage. Lung fibroblasts play a major role in tissue repair. Previous studies have reported smoking-associated changes in fibroblast responses and methylation patterns. Our aim was to identify the effect of current smoking on miRNA expression in primary lung fibroblasts. Small RNA sequencing was performed on lung fibroblasts from nine current and six ex-smokers with normal lung function. MiR-335-5p and miR-335-3p were significantly downregulated in lung fibroblasts from current compared to ex-smokers (false discovery rate (FDR) <0.05). Differential miR-335-5p expression was validated with RT-qPCR (p-value = 0.01). The results were validated in lung tissue from current and ex-smokers and in bronchial biopsies from non-diseased smokers and never-smokers (p-value <0.05). The methylation pattern of the miR-335 host gene, determined by methylation-specific qPCR, did not differ between current and ex-smokers. To obtain insights into the genes regulated by miR-335-5p in fibroblasts, we overlapped all proven miR-335-5p targets with our previously published miRNA targetome data in lung fibroblasts. This revealed Rb1, CARF, and SGK3 as likely targets of miR-335-5p in lung fibroblasts. Our study indicates that miR-335-5p downregulation due to current smoking may affect its function in lung fibroblasts by targeting Rb1, CARF and SGK3.

CDYL promotes the chemoresistance of small cell lung cancer by regulating H3K27 trimethylation at the CDKN1C promoter

Rationale: Chemoresistance frequently occurs in patients with small cell lung cancer (SCLC) and leads to a dismal prognosis. However, the mechanisms underlying this process remain largely unclear.

Methods: The effects of chromodomain Y-like (CDYL) on chemoresistance in SCLC were determined using Western blotting, immunohistochemistry, cell counting kit-8 assays, flow cytometry, and tumorigenicity experiments, and the underlying mechanisms were investigated using mRNA sequencing, chromatin immunoprecipitation-qPCR, electrophoretic mobility shift assays, co-immunoprecipitation, GST pull down assays, bisulfite sequencing PCR, ELISA, and bioinformatics analyses.

Results: CDYL is expressed at high levels in chemoresistant SCLC tissues from patients, and elevated CDYL levels correlate with an advanced clinical stage and a poor prognosis. Furthermore, CDYL expression is significantly upregulated in chemoresistant SCLC cells. Using gain- and loss-of-function methods, we show that CDYL promotes chemoresistance in SCLC in vitro and in vivo. Mechanistically, CDYL promotes SCLC chemoresistance by silencing its downstream mediator cyclin-dependent kinase inhibitor 1C (CDKN1C). Further mechanistic investigations showed that CDYL recruits the enhancer of zeste homolog 2 (EZH2) to regulate trimethylation of lysine 27 in histone 3 (H3K27me3) at the CDKN1C promoter region and promotes transcriptional silencing. Accordingly, the EZH2 inhibitor GSK126 de-represses CDKN1C and decreases CDYL-induced chemoresistance in SCLC.

Principal conclusions: Based on these results, the CDYL/EZH2/CDKN1C axis promotes chemoresistance in SCLC, and these markers represent promising therapeutic targets for overcoming chemoresistance in patients with SCLC.

The Ambivalent Function of YAP in Apoptosis and Cancer

Yes-associated protein, a core regulator of the Hippo-YAP signaling pathway, plays a vital role in inhibiting apoptosis. Thus, several studies and reviews suggest that yes-associated protein is a good target for treating cancer. Unfortunately, more and more evidence demonstrates that this protein is also an essential contributor of p73-mediated apoptosis. This questions the concept that yes-associated protein is always a good target for developing novel anti-cancer drugs. Thus, the aim of this review was to evaluate the clinical relevance of yes-associated protein for cancer pathophysiology. This review also summarized the molecules, processes and drugs, which regulate Hippo-YAP signaling and discusses their effect on apoptosis. In addition, issues are defined, which should be addressed in the future in order to provide a solid basis for targeting the Hippo-YAP signaling pathway in clinical trials.

Identification of H2O2 induced oxidative stress associated microRNAs in HLE-B3 cells and their clinical relevance to the progression of age-related nuclear cataract

BACKGROUND

This study is aimed to screen out the microRNAs (miRNAs) associated with H₂O₂ induced oxidative stress in human lens epithelial B3 (HLE-B3) cell lines and investigate their relations with the progression of age-related nuclear cataract.

METHODS

H₂O₂ was used to induce oxidative stress in HLE-B3 cells. A genome-wide expression profiling of miRNAs in HLE-B3 cells was performed to select the differentially expressed miRNAs before and after H₂O₂ treatment. The selected miRNAs were validated by RT-PCR and fluorescence in situ hybridization (FISH). Clinical specimens were divided into three groups according to the Lens Opacities Classification System III (LOCSIII) and the expression levels of the selected miRNAs were tested by RT-PCR in the three groups. Bioinformatics analyses were applied to predict the target genes of the miRNA hits and construct the miRNA regulatory network. The expression level of MAPK14 was analyzed by Western blot.

RESULTS

The H₂O₂ induced oxidative stress model of HLE-B3 cells was established. Nineteen upregulated and 30 downregulated miRNAs were identified as differentially expressed miRNAs. Seven of the total 49 were validated in the cell model. RT-PCR of the clinical samples showed that the expression levels of miR-34a-5p, miR-630 and miR-335-3p were closely related with the severity of nuclear opacity. The images taken from FISH confirmed the results of RT-PCR. There were 172 target genes of the three miRNAs clustered in the category of response to stress. The regulatory network demonstrated that 23 target genes were co-regulated by multiple miRNAs. MAPK14 was the target gene of three miRNAs and the result were verified by Western blot.

CONCLUSION

Up-regulation of miR-34a-5p and miR-630 and down-regulation of miR-335-3p are related with the progression of age-related nuclear cataract and the underlying mechanism awaits further functional research to reveal.

[Role of Hippo Signaling Pathway in Lung Cancer]

肺癌是全世界范围内肿瘤相关性死亡的首要原因，每年死亡人数超过100万人，占全球癌症死亡人数的五分之一。虽然目前在手术、放化疗、靶向治疗、免疫治疗肺癌方面取得了一定进展，但患者的预后仍不理想。因此，亟待寻找评价预后的分子标志物和肺癌的治疗新靶点，为肺癌患者提供生存获益的有效方法。近年来，Hippo信号通路逐渐成为国内外肿瘤研究领域中新兴且热门的研究方向。Hippo信号通路激活时，其核心组件MST/MOB、LATS1/2等能抑制转录的共激活剂YAP/TAZ的转录，二者被磷酸化并滞留在细胞浆中，从而抑制肺癌的发生发展。因此Hippo信号通路在临床应用中的潜在价值也越来越受关注。本篇文章总结了Hippo信号通路核心组成元件及上下游调控因子在肺癌形成进展过程中的重要作用和分子机制，并对Hippo信号通路的研究前景进行展望。

N-peptide of vMIP-Ⅱ reverses paclitaxel-resistance by regulating miRNA-335 in breast cancer

Acquisition of resistance to paclitaxel is one of the most important problems in treatment of breast cancer patients, but the molecular mechanisms underlying sensitivity to paclitaxel remains elusive. Emerging evidence has demonstrated that microRNAs (miRNAs) play important roles in regulation of cell growth, migration and invasion through inhibiting the expression of its target genes. In our previous studies, we have shown that microRNA-335 (miR‑335) decreased obviously between paclitaxel-resistant (PR) and parental breast cancer cells through miRNA microarray. However, the roles of miR‑335 in breast cancer progression and metastasis are still largely unknown. NT21MP was designed and synthesized as an antagonist with CXCR4 to inhibit cellular proliferation and induce apoptosis. Therefore, the aim of this study was to explore the underlying mechanism of miR‑335 and NT21MP in reverse PR in breast cancer cells. In this study, we found that miR‑335 expression is significantly lower in PR MCF‑7 and SKBR-3 cells (MCF‑7/PR and SKBR-3/PR) compared with their parental MCF‑7 and SKBR-3 cells. Functional experiments showed that overexpression of miR‑335 and NT21MP increased the number of apoptosis cells, arrested cells in G0/G1 phase transition, and suppressed cell migration and invasion in vitro. Dual luciferase assays revealed that SETD8 is a direct target gene of miR‑335. Furthermore, miR‑335 markedly inhibited expression of SETD8 via Wnt/β‑catenin signaling and subsequently inhibited the expression of its downstream genes cyclin D1, and c‑Myc. Additionally, ectopic expression of miR‑335 or depletion of its target gene SETD8 could enhance the sensitivity of PR cells to paclitaxel. Taken together, these date elucidated that NT21MP and miR‑335 mediated PR of breast cancer cells partly through regulation of Wnt/β‑catenin signaling pathway. Activation of miR‑335 or inactivation of SETD8 could be a novel approach for the treatment of breast cancer.

The long noncoding RNA HOTAIR activates the Hippo pathway by directly binding to SAV1 in renal cell carcinoma

The long noncoding RNA HOTAIR promotes the development and progression of several tumors. Here, the clinical significance and role of HOTAIR in renal cell carcinoma (RCC) tumorigenesis were explored. The results showed that increased expression of HOTAIR predicted a poor prognosis of RCC after surgery. HOTAIR promoted RCC cell proliferation and growth in vitro and in vivo. The expressions of HOTAIR and Salvador homolog 1 (SAV1) were inversely correlated in clinical RCC samples. HOTAIR downregulated SAV1 by directly binding to the SAV1 protein and enhanced histone H3K27 methylation. Loss of function of SAV1 activated the Hippo pathway. HOTAIR could be a potential therapeutic target in RCC.