Suppression of TGF-β1 enhances chemosensitivity of cisplatin-resistant lung cancer cells through the inhibition of drug-resistant proteins

Desmethylclomipramine triggers mitochondrial damage and death in TGF-β-induced mesenchymal type of A549 cells

Lung cancer is the leading cause of cancer deaths, where the metastasis often causes chemodrug resistance and leads to recurrence after treatment. Desmethylclomipramine (DCMI), a bioactive metabolite of clomipramine, shows the therapeutic efficacy with antidepressive agency as well as potential cytostatic effects on lung cancer cells. Here, we demonstrated that DCMI effectively caused transforming growth factor (TGF)-β1-mediated mesenchymal type of A549 cells to undergo mitochondrial death via myeloid cell leukemia-1 (Mcl-1) suppression and activation of truncated Bid (tBid). TGF-β1 induced epithelial mesenchymal transition in A549 cells with the increase of fibronectin and decrease of E-cadherin, the activation of Akt/glycogen synthase kinase-3β (GSK-β)/Mcl-1 axis, and the hypo-responsiveness to cisplatin. DCMI initiated a dose-dependent cytotoxicity on TGF-β1-mediated mesenchymal type of A549 cells through inactivating Akt/GSK-β/Mcl-1 axis, in which mitochondria instability and caspase-9/3 activation also occurred concurrently. Pharmacological inhibition of caspase-8 and cathepsin B partly reversed tBid expression and mitochondrial damage to further attenuate DCMI-mediated cytotoxicity. Additionally, DCMI presented partial therapeutic effects in treating mesenchymal type of A549 tumor bearing nude mice through an acceleration of cancer cell death. Taken together, DCMI exerts antitumor effects via initiating the mechanisms of Akt/GSK-β/Mcl-1 inactivation and cathepsin B/caspase-8-regulated mitochondrial death, which suggests its potential role in mesenchymal type of cancer cell therapy.

Molecular cloning and functional analyses of C-C motif chemokine ligand 3 (CCL3) in mandarin fish Siniperca chuatsi

Chemokines are critical molecules involved in immune reaction and immune system homeostasis, and some chemokines play a role in antiviral immunity. It is not known if the C-C motif chemokine ligand 3 (CCL3), a member of the CC chemokine family, possesses antiviral properties in fish. In this study, a ccl3 was cloned from the mandarin fish (Siniperca chuatsi), and it has an open reading frame (ORF) of 276 base pairs, which are predicted to encode a 91-amino acid peptide. Mandarin fish CCL3 revealed conserved sequence features with four cysteine residues and closely relationships with the CCL3s from other vertebrates based on the sequence alignment and phylogenetic analysis. The transcripts of ccl3 were notably enriched in immune-related organs, such as spleen and gills in healthy mandarin fish, and the ccl3 was induced in the isolated mandarin fish brain (MFB) cells following infection with infectious spleen and kidney necrosis virus (ISKNV). Moreover, in MFB cells, overexpression of CCL3 induced immune factors, such as IL1β, TNFα, MX, IRF1 and IFNh, and exhibited antiviral activity against ISKNV. This study sheds light on the immune role of CCL3 in immune response of mandarin fish, and its antiviral defense mechanism is of interest for further investigation.

Meta-analysis of microarray data to determine gene indicators involved in cisplatin resistance in non-small cell lung cancer

BACKGROUND

Lung cancer is a major cause of cancer-related mortality worldwide, with a 5-year survival rate of approximately 22%. Cisplatin is one of the standard first-line chemotherapeutic agents for non-small cell lung cancer (NSCLC), but its efficacy is often limited by the development of resistance. Despite extensive research on the molecular mechanisms of chemoresistance, the underlying causes remain elusive and complex.

AIMS

We analyzed three microarray datasets to find the gene signature and key pathways related to cisplatin resistance in NSCLC.

METHODS AND RESULTS

We compared the gene expression of sensitive and resistant NSCLC cell lines treated with cisplatin. We found 274 DEGs, including 111 upregulated and 163 downregulated genes, in the resistant group. Gene set enrichment analysis showed the potential roles of several DEGs, such as TUBB2B, MAPK7, TUBAL3, MAP2K5, SMUG1, NTHL1, PARP3, NTRK1, G6PD, PDK1, HEY1, YTHDF2, CD274, and MAGEA1, in cisplatin resistance. Functional analysis revealed the involvement of pathways, such as gap junction, base excision repair, central carbon metabolism, and Notch signaling in the resistant cell lines.

CONCLUSION

We identified several molecular factors that contribute to cisplatin resistance in NSCLC cell lines, involving genes and pathways that regulate gap junction communication, DNA damage repair, ROS balance, EMT induction, and stemness maintenance. These genes and pathways could be targets for future studies to overcome cisplatin resistance in NSCLC.

The diverse effects of cisplatin on tumor microenvironment: Insights and challenges for the delivery of cisplatin by nanoparticles

Cisplatin is a well-known platinum-based chemotherapy medication that is widely utilized for some malignancies. Despite the direct cytotoxic consequences of cisplatin on tumor cells, studies in the recent decade have revealed that cisplatin can also affect different cells and their secretions in the tumor microenvironment (TME). Cisplatin has complex impacts on the TME, which may contribute to its anti-tumor activity or drug resistance mechanisms. These regulatory effects of cisplatin play a paramount function in tumor growth, invasion, and metastasis. This paper aims to review the diverse impacts of cisplatin and nanoparticles loaded with cisplatin on cancer cells and also non-cancerous cells in TME. The impacts of cisplatin on immune cells, tumor stroma, cancer cells, and also hypoxia will be discussed in the current review. Furthermore, we emphasize the challenges and prospects of using cisplatin in combination with other adjuvants and therapeutic modalities that target TME. We also discuss the potential synergistic effects of cisplatin with immune checkpoint inhibitors (ICIs) and other agents with anticancer potentials such as polyphenols and photosensitizers. Furthermore, the potential of nanoparticles for targeting TME and better delivery of cisplatin into tumors will be discussed.

TGF-β mediated drug resistance in solid cancer

Transforming growth factor β (TGF-β) is an important signaling molecule which is expressed in three different isoforms in mammals (i.e. TGF-β1, -β2, and -β3). The interaction between TGF-β and its receptor triggers several pathways, which are classified into SMAD-dependent (canonical) and SMAD-independent (non-canonical) signaling, whose activation/transduction is finely regulated by several mechanisms. TGF-β is involved in many physiological and pathological processes, assuming a dualistic role in cancer progression depending on tumor stage. Indeed, TGF-β inhibits cell proliferation in early-stage tumor cells, while it promotes cancer progression and invasion in advanced tumors, where high levels of TGF-β have been reported in both tumor and stromal cells. In particular, TGF-β signaling has been found to be strongly activated in cancers after treatment with chemotherapeutic agents and radiotherapy, resulting in the onset of drug resistance conditions. In this review we provide an up-to-date description of several mechanisms involved in TGF-β-mediated drug resistance, and we report different strategies that are currently under development in order to target TGF-β pathway and increase tumor sensitivity to therapy.

The Role of DNA Damage and Repair in Idiopathic Pulmonary Fibrosis

The mortality rate of idiopathic pulmonary fibrosis (IPF) increases yearly due to ineffective treatment. Given that the lung is exposed to the external environment, it is likely that oxidative stress, especially the stimulation of DNA, would be of particular importance in pulmonary fibrosis. DNA damage is known to play an important role in idiopathic pulmonary fibrosis initiation, so DNA repair systems targeting damage are also crucial for the survival of lung cells. Although many contemporary reports have summarized the role of individual DNA damage and repair pathways in their hypotheses, they have not focused on idiopathic pulmonary fibrosis. This review, therefore, aims to provide a concise overview for researchers to understand the pathways of DNA damage and repair and their roles in IPF.

Pyruvate Dehydrogenase Contributes to Drug Resistance of Lung Cancer Cells Through Epithelial Mesenchymal Transition

Recently, there has been a growing interest on the role of mitochondria in metastatic cascade. Several reports have shown the preferential utilization of glycolytic pathway instead of mitochondrial respiration for energy production and the pyruvate dehydrogenase (PDH) has been considered to be a contributor to this switch in some cancers. Since epithelial mesenchymal transition (EMT) is proposed to be one of the significant mediators of metastasis, the molecular connections between cancer cell metabolism and EMT may reveal underlying mechanisms and improve our understanding on metastasis. In order to explore a potential role for PDH inhibition on EMT and associated drug resistance, we took both pharmacological and genetic approaches, and selectively inhibited or knocked down PDHA1 by using Cpi613 and shPDHA1, respectively. We found that both approaches triggered morphological changes and characteristics of EMT (increase in mesenchymal markers). This change was accompanied by enhanced wound healing and an increase in migration. Interestingly, cells were more resistant to many of the clinically used chemotherapeutics following PDH inhibition or PDHA1 knockdown. Furthermore, the TGFβRI (known as a major inducer of the EMT) inhibitor (SB-431542) together with the PDHi, was effective in reversing EMT. In conclusion, interfering with PDH induced EMT, and more importantly resulted in chemoresistance. Therefore, our study demonstrates the need for careful consideration of PDH-targeting approaches in cancer treatment.

Pathogenesis and therapeutic strategy in platinum resistance lung cancer

Platinum compounds (cisplatin and carboplatin) represent the most active anticancer agents in clinical use both of lung cancer in mono-and combination therapies. However, platinum resistance limits its clinical application. It is necessary to understand the molecular mechanism of platinum resistance, identify predictive markers, and develop newer, more effective and less toxic agents to treat platinum resistance in lung cancer. Here, it summarizes the main molecular mechanisms associated with platinum resistance in lung cancer and the development of new approaches to tackle this clinically relevant problem. Moreover, it could lead to the development of more effective treatment for refractory lung cancer in future.

Hypoxia-induced antizyme inhibitors 2 regulates cisplatin resistance through epithelia-mesenchymal transition pathway in non-small cell lung cancer

Antizyme inhibitors 2 (AZIN2) was found to be associated with poor prognosis of patients with rectal cancer. However, no studies have reported whether AZIN2 functions in non-small cell lung cancer (NSCLC). This study aimed to investigate the role of AZIN2 in cisplatin (DDP) resistance in NSCLC. We established DDP resistant A549 and H1299 cell lines. The transcriptional and translational expression levels were examined using quantitative real-time polymerase chain reaction and western blot. Cell apoptosis was evaluated by caspase-3 activity and nucleosome ELISA assays. Luciferase reporter assay was employed to evaluate the impact of hypoxia-inducible factor (HIF-1α) on AZIN2 transcription. AZIN2 expression was found to be associated with DDP resistance and poor prognosis in patients with NSCLC. AZIN2 overexpression promoted cell viability, colony formation, and reduced cell apoptosis in H1299 cells and A549 upon DDP treatment. Correspondingly, AZIN2 knockdown significantly inhibited cell viability and colony formation, and increased cell apoptosis upon DDP treatment. Interestingly, AZIN2 expression in NSCLC cells was significantly induced by hypoxia condition. The occupancy of HIF-1α, an important regulator of the hypoxia response, remarkably enriched at the promoter region of AZIN2 under hypoxia condition. In addition, AZIN2 overexpression resulted in epithelial-mesenchymal transition (EMT). The results suggested that hypoxia-induced AZIN2 high expression may contribute to DDP resistance development by promoting the EMT.

A highly annotated database of genes associated with platinum resistance in cancer

Platinum-based chemotherapy, including cisplatin, carboplatin, and oxaliplatin, is prescribed to 10-20% of all cancer patients. Unfortunately, platinum resistance develops in a significant number of patients and is a determinant of clinical outcome. Extensive research has been conducted to understand and overcome platinum resistance, and mechanisms of resistance can be categorized into several broad biological processes, including (1) regulation of drug entry, exit, accumulation, sequestration, and detoxification, (2) enhanced repair and tolerance of platinum-induced DNA damage, (3) alterations in cell survival pathways, (4) alterations in pleiotropic processes and pathways, and (5) changes in the tumor microenvironment. As a resource to the cancer research community, we provide a comprehensive overview accompanied by a manually curated database of the >900 genes/proteins that have been associated with platinum resistance over the last 30 years of literature. The database is annotated with possible pathways through which the curated genes are related to platinum resistance, types of evidence, and hyperlinks to literature sources. The searchable, downloadable database is available online at http://ptrc-ddr.cptac-data-view.org .

MiR-132 inhibits migration and invasion and increases chemosensitivity of cisplatin-resistant oral squamous cell carcinoma cells via targeting TGF-β1

Numerous findings have demonstrated that MicroRNAs dysregulation plays a key role in many neoplasms, including oral squamous cell carcinoma (OSCC), yet the potential mechanisms of microRNAs in chemo-resistance remain elusive. Here, we analyzed the miR-132 expression in OSCC tissues and OSCC cell lines, and explored it role and mechanisms on invasion and migration and cisplatin (CDDP)-induced cell death. The clinical tissues of 37 patients with OSCCs and paired normal tissues were collected. The miR-132 expression in OSCC tissues and cell lines were detected by reverse transcription-quantitative polymerase chain reation (RT-qPCR). The in vitro repopulation models were established to mimic the biological processes of OSCC. The results showed that miR-132 expression was significantly decreased in the OSCC tissues and CDDP resistant OSCC cell line (CAL-27/CDDP). miR-132 mimic inhibited cell proliferation, invasion, migration and enhanced the pro-apoptotic ability of CDDP. On the contrary, downregulation of miR-132 promoted proliferation, invasion, migration and conferred OSCC cell resistance to CDDP-induced apoptosis in vitro. The TGF-β1 expression in OSCC tissues and CAL-27/CDDP cells was significantly higher. miR-132 significantly inhibited the TGF-β1/Smad2/3 signals. TGF-β1 upregulation significantly promoted OSCC cell proliferation and resumed OSCC cell chemo-resistance in the miR-132 overexpressing cells, which is contrary to the function of miR-132. In summary, miR-132 acts as a tumor suppressor and exerts a substantial role in inhibiting the proliferation, invasion, and enhanced the chemosensitivity to CDDP of OSCC via regulating TGF-β1/Smad2/3 signals in vitro. These observations indicate that miR-132 may be a suitable therapeutic target for the treatment of OSCC.

N6-Methyladenosine modification of the TRIM7 positively regulates tumorigenesis and chemoresistance in osteosarcoma through ubiquitination of BRMS1

BACKGROUND

Metastasis is the leading cause of death in patients with osteosarcoma. Some of these patients fail to respond to chemotherapy and die of metastasis within a short period. Therefore, it is important to identify novel biomarkers to improve the diagnosis and treatment of osteosarcoma. TRIM7 is a member of the tripartite motif (TRIM) family protein that is involved in various pathological conditions including cancer; however, its role in osteosarcoma remains elusive.

METHODS

Cell proliferation, invasion and migration were measured by CCK-8 and Transwell. Immunoprecipitation and mass spectrometry analysis were used to identify candidate proteins associated with TRIM7. Immunoprecipitation, immunofluorescence, pull down and ubiquitination assay were performed to examine the regulation between TRIM7 and its candidate protein. m6A modification of TRIM7 was measured by RNA immunoprecipitation.

FINDINGS

TRIM7 expression was upregulated in osteosarcoma tissues and was an independent risk factor in predicting poor prognosis. TRIM7 regulates osteosarcoma cell migration and invasion through ubiquitination of breast cancer metastasis suppressor 1 (BRMS1). Moreover, chemoresistance was readily observed in osteosarcoma cells and in patient-derived xenograft (PDX) mice with higher TRIM7 levels. Loss of TRIM7 m6A modification was observed in osteosarcoma tissues. METTL3 and YTHDF2 were the main factors involved in the aberrant m6A modification of TRIM7.

INTERPRETATION

Overall, our findings show that TRIM7 plays a key role in regulating metastasis and chemoresistance in osteosarcoma through ubiquitination of BRMS1.

FUNDING

This work was financially supported by grants of NSFC (81001192, 81672658 and 81972521) and National Key Research Project of Science and Technology Ministry (2016YFC0106204).

Tumor microenvironment and epithelial mesenchymal transition as targets to overcome tumor multidrug resistance

It is well established that multifactorial drug resistance hinders successful cancer treatment. Tumor cell interactions with the tumor microenvironment (TME) are crucial in epithelial-mesenchymal transition (EMT) and multidrug resistance (MDR). TME-induced factors secreted by cancer cells and cancer-associated fibroblasts (CAFs) create an inflammatory microenvironment by recruiting immune cells. CD11b+/Gr-1+ myeloid-derived suppressor cells (MDSCs) and inflammatory tumor associated macrophages (TAMs) are main immune cell types which further enhance chronic inflammation. Chronic inflammation nurtures tumor-initiating/cancer stem-like cells (CSCs), induces both EMT and MDR leading to tumor relapses. Pro-thrombotic microenvironment created by inflammatory cytokines and chemokines from TAMs, MDSCs and CAFs is also involved in EMT and MDR. MDSCs are the most common mediators of immunosuppression and are also involved in resistance to targeted therapies, e.g. BRAF inhibitors and oncolytic viruses-based therapies. Expansion of both cancer and stroma cells causes hypoxia by hypoxia-inducible transcription factors (e.g. HIF-1α) resulting in drug resistance. TME factors induce the expression of transcriptional EMT factors, MDR and metabolic adaptation of cancer cells. Promoters of several ATP-binding cassette (ABC) transporter genes contain binding sites for canonical EMT transcription factors, e.g. ZEB, TWIST and SNAIL. Changes in glycolysis, oxidative phosphorylation and autophagy during EMT also promote MDR. Conclusively, EMT signaling simultaneously increases MDR. Owing to the multifactorial nature of MDR, targeting one mechanism seems to be non-sufficient to overcome resistance. Targeting inflammatory processes by immune modulatory compounds such as mTOR inhibitors, demethylating agents, low-dosed histone deacetylase inhibitors may decrease MDR. Targeting EMT and metabolic adaptation by small molecular inhibitors might also reverse MDR. In this review, we summarize evidence for TME components as causative factors of EMT and anticancer drug resistance.

Association of the Epithelial-Mesenchymal Transition (EMT) with Cisplatin Resistance

Therapy resistance is a characteristic of cancer cells that significantly reduces the effectiveness of drugs. Despite the popularity of cisplatin (CP) as a chemotherapeutic agent, which is widely used in the treatment of various types of cancer, resistance of cancer cells to CP chemotherapy has been extensively observed. Among various reported mechanism(s), the epithelial-mesenchymal transition (EMT) process can significantly contribute to chemoresistance by converting the motionless epithelial cells into mobile mesenchymal cells and altering cell-cell adhesion as well as the cellular extracellular matrix, leading to invasion of tumor cells. By analyzing the impact of the different molecular pathways such as microRNAs, long non-coding RNAs, nuclear factor-κB (NF-ĸB), phosphoinositide 3-kinase-related protein kinase (PI3K)/Akt, mammalian target rapamycin (mTOR), and Wnt, which play an important role in resistance exhibited to CP therapy, we first give an introduction about the EMT mechanism and its role in drug resistance. We then focus specifically on the molecular pathways involved in drug resistance and the pharmacological strategies that can be used to mitigate this resistance. Overall, we highlight the various targeted signaling pathways that could be considered in future studies to pave the way for the inhibition of EMT-mediated resistance displayed by tumor cells in response to CP exposure.

High Stromal TGFBI in Lung Cancer and Intratumoral CD8-Positive T Cells were Associated with Poor Prognosis and Therapeutic Resistance to Immune Checkpoint Inhibitors

BACKGROUND

We investigated whether the expression of transforming growth factor-beta-induced protein (TGFBI) and intratumoral immune cells including CD8- and Forkhead box protein P3 (Foxp3)-positive T cells in clinical lung cancer patients could predict the therapeutic response to nivolumab.

METHODS

Thirty-three patients who were treated with nivolumab were enrolled in this study. Immunohistochemical analyses of TGFBI, PD-L1, CD8, Foxp3, and vimentin expression were conducted. Serum concentrations of TGFBI and transforming growth factor-beta1 (TGF-β1) were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Cancer TGFBI was not associated with prognosis and therapeutic response to nivolumab, but cancer stromal TGFBI and intratumoral CD8-positive T cells were associated with them. Therefore, we evaluated cancer stromal TGFBI and intratumoral CD8-positive T cells. The high-TGFBI-expression group had poorer clinical responses than did the low-TGFBI-expression group (p < 0.0001). The number of times nivolumab was administered in the high-CD8-expression group was significantly higher than that in the low-CD8-expression group (p = 0.0046). The high-CD8-expression group had better clinical responses than did the low-CD8-expression group (p = 0.0013). Interestingly, all patients in the high-TGFBI/low-CD8-expression group had progressive disease (PD). In contrast, all patients in the low-TGFBI/high-CD8-expression group had PR + SD (partial response + stable disease) by the Response Evaluation Criteria in Solid Tumors (RECIST 1.1).

CONCLUSIONS

The dual evaluation of stromal TGFBI and intratumoral CD8-positive T cells could be a useful predictive marker for nivolumab.

Dehydrogenase/reductase SDR family member 2 silencing sensitizes an oxaliplatin‑resistant cell line to oxaliplatin by inhibiting excision repair cross‑complementing group 1 protein expression

Oxaliplatin (Oxa)-based chemotherapy is widely used as the first-line treatment for colorectal cancer (CRC). However, Oxa-resistance is common for many postoperative CRC patients. To explore drug resistance in CRC, an Oxa-resistant cell line, HCT116/Oxa, was established from parental HCT116 cells. These Oxa-resistant cells exhibited characteristics of epithelial-mesenchymal transition (EMT) and a higher migratory capacity than parental cells. Protein profiles of HCT116/Oxa and HCT116 cells were compared using a tandem mass tag-based quantitative proteomics technique. The protein dehydrogenase/reductase SDR family member 2 (DHRS2) was revealed to be highly expressed in HCT116/Oxa cells. Silencing of DHRS2 in HCT116/Oxa cells effectively restored Oxa-sensitivity by suppressing the expression of excision repair cross-complementing group 1 protein via a p53-dependent pathway, and reversed the EMT phenotype. Overall, the suppression of DHRS2 expression may be a promising strategy for the prevention of Oxa-resistance in CRC.

Cell signaling and cancer: a mechanistic insight into drug resistance

Drug resistance is a major setback for advanced therapeutics in multiple cancers. The increasing prevalence of this resistance is a growing concern and bitter headache for the researchers since a decade. Hence, it is essential to revalidate the existing strategies available for cancer treatment and to look after a novel therapeutic approach for target based killing of cancer cells at the genetic level. This review outlines the different mechanisms enabling resistance including drug efflux, drug target alternation, alternative splicing, the release of the extracellular vesicle, tumor heterogeneity, epithelial-mesenchymal transition, tumor microenvironment, the secondary mutation in the receptor, epigenetic alternation, heterodimerization of receptors, amplification of target and amplification of components rather than the target. Furthermore, existing evidence and the role of various signaling pathways like EGFR, Ras, PI3K/Akt, Wnt, Notch, TGF-β, Integrin-ECM signaling in drug resistance are explained. Lastly, the prevention of this resistance by a contemporary therapeutic strategy, i.e., a combination of specific signaling pathway inhibitors and the cocktail of a cancer drug is summarized showing the new treatment strategies.

Targeting HDAC/OAZ1 axis with a novel inhibitor effectively reverses cisplatin resistance in non-small cell lung cancer

Cisplatin yields significant efficacy and is generally used as a frontline therapy for non-small cell lung cancer (NSCLC). However, acquired resistance strongly limits its application. Here, we identified that a novel histone deacetylase (HDAC) inhibitor S11, with P-glycoprotein inhibitory activity, could obviously suppress cell growth in cisplatin-resistant NSCLC cell lines. In addition, S11 could increase the expression of Ac-H4 and p21, which confirmed its HDAC inhibitory action, suppress colony formation, and block cell migration of cisplatin-resistant NSCLC cells. Notably, co-treatment with S11 and cisplatin exhibited synergistically inhibitory efficacy in cisplatin-resistant NSCLC cells. Gene microarray data showed that OAZ1 was downregulated in resistant cells but upregulated after S11 treatment. Further study indicated that knockdown of OAZ1 by siRNA resulted in the decrease of sensitivity of resistant cells to cisplatin treatment and contributed to the increase of resistant cell migration. Additionally, ChIP assay data demonstrated that HDAC inhibitor S11 could increase the accumulation of Ac-H4 in OAZ1 promoter region, suggesting the direct regulation of OAZ1 by HDAC. Importantly, the combination of S11 and cisplatin overcome resistance through inhibiting HDAC activity and subsequently increasing the OAZ1 expression in preclinical model. Moreover, we observed that positive expression of HDAC1 was associated with the downregulation of OAZ1 in NSCLC patients with platinum-based treatment, and predicted drug resistance and poor prognosis. In summary, we demonstrated a role of HDAC/OAZ1 axis in cisplatin-resistant NSCLC and identified a promising compound to overcome cisplatin resistance.

Suppression of YAP by DDP disrupts colon tumor progression

Colon cancer is a commonly diagnosed cancer that often has a poor prognosis. Combined with the development of drug resistance to cancer treatment agents the treatment efficacy of colon cancer can be limited. Activation of the oncogene YAP has been shown to be related to colon cancer progression and is associated with poor prognosis, drug resistance and metastasis, even under treatment. Cisplatin (DDP) is a commonly used drug that can control carcinoma progression, although its mechanisms are poorly understood. In the present study, we examined whether DDP specifically suppressed YAP in order to inhibit colon carcinoma progression. Our data revealed that Mst/Yap signaling was unusually activated in colon cancers, promoting cell proliferation and invasion. DDP treatment decreased the expression of YAP at both the transcriptional and post-translational levels, leading to cell cycle arrest, apoptosis and senescence in cancer cells, in addition to decreasing epithelial-to-mesenchymal transition, cell motility and in vitro cell invasion and migration. Ultimately, DDP increased the expression of E-cadherin and decreased the expression of vimentin. The present study also revealed that post-translational regulation of YAP phosphorylation controlled the subcellular distribution between the nucleus and the cytoplasm. In conclusion, the findings of the present study revealed that DDP was a suitable therapeutic candidate for colon cancer that specifically targets the Mst/Yap signaling pathway.