A Novel tsRNA, m7G-3' tiRNA LysTTT, Promotes Bladder Cancer Malignancy Via Regulating ANXA2 Phosphorylation.

Emerging evidence indicates that transfer RNA (tRNA)-derived small RNAs (tsRNAs), originated from tRNA with high abundance RNA modifications, play an important role in many complex physiological and pathological processes. However, the biological functions and regulatory mechanisms of modified tsRNAs in cancer remain poorly understood. Here, it is screened for and confirmed the presence of a novel m7G-modified tsRNA, m7G-3'-tiRNA LysTTT (mtiRL), in a variety of chemical carcinogenesis models by combining small RNA sequencing with an m7G small RNA-modified chip. Moreover, it is found that mtiRL, catalyzed by the tRNA m7G-modifying enzyme mettl1, promotes bladder cancer (BC) malignancy in vitro and in vivo. Mechanistically, mtiRL is found to specifically bind the oncoprotein Annexin A2 (ANXA2) to promote its Tyr24 phosphorylation by enhancing the interactions between ANXA2 and Yes proto-oncogene 1 (Yes1), leading to ANXA2 activation and increased p-ANXA2-Y24 nuclear localization in BC cells. Together, these findings define a critical role for mtiRL and suggest that targeting this novel m7G-modified tsRNA can be an efficient way for to treat BC.

FAT1 inhibits the proliferation of DLBCL cells via increasing the m6A modification of YAP1 mRNA.

Emerging evidence shows that FAT atypical cadherin 1 (FAT1) mutations occur in lymphoma and are associated with poorer overall survival. Considering that diffuse large B cell lymphoma (DLBCL) is the category of lymphoma with the highest incidence rate, this study aims to explore the role of FAT1 in DLBCL. The findings demonstrate that FAT1 inhibits the proliferation of DLBCL cell lines by downregulating the expression of YAP1 rather than by altering its cellular localization. Mechanistic analysis via meRIP-qPCR/luciferase reporter assays showed that FAT1 increases the m6A modification of YAP1 mRNA 3'UTR and the subsequent binding of heterogeneous nuclear ribonucleoprotein D (HNRNPD) to the m6A modified YAP1 mRNA, thus decreasing the stability of YAP1 mRNA. Furthermore, FAT1 increases YAP1 mRNA 3'UTR m6A modification by decreasing the activity of the TGFß-Smad2/3 pathway and the subsequent expression of ALKBH5, which is regulated at the transcriptional level by Smad2/3. Collectively, these results reveal that FAT1 inhibits the proliferation of DLBCL cells by increasing the m6A modification of the YAP1 mRNA 3'UTR via the TGFß-Smad2/3-ALKBH5 pathway. The findings of this study therefore indicate that FAT1 exerts anti-tumor effects in DLBCL and may represent a novel target in the treatment of this form of lymphoma.

YES1 as a potential target to overcome drug resistance in EGFR-deregulated non-small cell lung cancer.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) such as gefitinib and osimertinib have primarily been used as first-line treatments for patients with EGFR-activating mutations in non-small cell lung cancer (NSCLC). Novel biomarkers are required to distinguish patients with lung cancer who are resistant to EGFR-TKIs. The aim of the study is to investigate the expression and functional role of YES1, one of the Src-family kinases, in EGFR-TKI-resistant NSCLC. YES1 expression was elevated in gefitinib-resistant HCC827 (HCC827/GR) cells, harboring EGFR mutations. Moreover, HCC827/GR cells exhibited increased reactive oxygen species (ROS) levels compared to those of the parent cells, resulting in the phosphorylation/activation of YES1 due to oxidation of the cysteine residue. HCC827/GR cells showed elevated expression levels of YES1-associated protein 1 (YAP1), NF-E2-related factor 2 (Nrf2), cancer stemness-related markers, and antioxidant proteins compared to those of the parent cells. Knockdown of YES1 in HCC827/GR cells suppressed YAP1 phosphorylation, leading to the inhibition of Bcl-2, Bcl-xL, and Cyclin D1 expression. Silencing YES1 markedly attenuated the proliferation, migration, and tumorigenicity of HCC827/GR cells. Dasatinib inhibited the proliferation of HCC827/GR cells by targeting YES1-mediated signaling pathways. Furthermore, the combination of gefitinib and dasatinib demonstrated a synergistic effect in suppressing the proliferation of HCC827/GR cells. Notably, YES1- and Nrf2-regulated genes showed a positive regulatory relationship in patients with lung cancer and in TKI-resistant NSCLC cell lines. Taken together, these findings suggest that modulation of YES1 expression and activity may be an attractive therapeutic strategy for the treatment of drug-resistant NSCLC.

Emerging Roles of YES1 in Cancer: The Putative Target in Drug Resistance.

Src family kinases (SFKs) are non-receptor tyrosine kinases that are recognized as proto-oncogenic products. Among SFKs, YES1 is frequently amplified and overexpressed in a variety of human tumors, including lung, breast, ovarian, and skin cancers. YES1 plays a pivotal role in promoting cell proliferation, survival, and invasiveness during tumor development. Recent findings indicate that YES1 expression and activation are associated with resistance to chemotherapeutic drugs and tyrosine kinase inhibitors in human malignancies. YES1 undergoes post-translational modifications, such as lipidation and nitrosylation, which can modulate its catalytic activity, subcellular localization, and binding affinity for substrate proteins. Therefore, we investigated the diverse mechanisms governing YES1 activation and its impact on critical intracellular signal transduction pathways. We emphasized the function of YES1 as a potential mechanism contributing to the anticancer drug resistance emergence.

LATS1 Promotes B-ALL Tumorigenesis by Regulating YAP1 Phosphorylation and Subcellular Localization.

OBJECTIVE: YAP1 plays a dual role as an oncogene and tumor suppressor gene in several tumors; differentiating between these roles may depend on the YAP1 phosphorylation pattern. The specific function of YAP1 in B cell acute lymphoblastic leukemia (B-ALL), however, is currently unclear. Thus, in the present study, the role of YAP1 in B-ALL was investigated using relevant cell lines and patient datasets. METHODS: The effects of shRNA-mediated knockdown on YAP1 and LATS1 levels in the NALM6 and MOLT-4 cell lines were examined using Western blotting, quantitative real-time polymerase chain reaction, flow cytometry, immunostaining, and nude mouse subcutaneous tumorigenesis experiments. Gene expression levels of Hippo pathway-related molecules before and after verteporfin (VP) treatment were compared using RNA-Seq to identify significant Hippo pathway-related genes in NALM6 cells. RESULTS: Patients with ALL showing high YAP1 expression and low YAP1-Ser127 phosphorylation levels had worse prognoses than those with low YAP1 protein expression and high YAP1-Ser127 phosphorylation levels. YAP1-Ser127 phosphorylation levels were lower in NALM6 cells than in MOLT-4 and control cells; YAP1 was distributed in the nuclei in NALM6 cells. Knockdown of YAP1 inhibited MOLT-4 and NALM6 cell proliferation and arrested the NALM6 cell cycle in the G0/G1 phase. Before and after VP treatment, the expression of the upstream gene LATS1 was upregulated; its overexpression promoted YAP1-Ser127 phosphorylation. Further, YAP1 was distributed in the plasma. CONCLUSION: LATS1 may downregulate YAP1-Ser127 phosphorylation and maintain B-ALL cell function; thus, VP, which targets this axis, may serve as a new therapeutic method for improving the outcomes for B-ALL patients.

Therapeutic strategy using novel RET/YES1 dual-target inhibitor in lung cancer.

Lung cancer represents a significant global health concern and stands as the leading cause of cancer-related mortality worldwide. The identification of specific genomic alterations such as EGFR and KRAS in lung cancer has paved the way for the development of targeted therapies. While targeted therapies for lung cancer exhibiting EGFR, MET and ALK mutations have been well-established, the options for RET mutations remain limited. Importantly, RET mutations have been found to be mutually exclusive from other genomic mutations and to be related with high incidences of brain metastasis. Given these facts, it is imperative to explore the development of RET-targeting therapies and to elucidate the mechanisms underlying metastasis in RET-expressing lung cancer cells. In this study, we investigated PLM-101, a novel dual-target inhibitor of RET/YES1, which exhibits notable anti-cancer activities against CCDC6-RET-positive cancer cells and anti-metastatic effects against YES1-positive cancer cells. Our findings shed light on the significance of the YES1-Cortactin-actin remodeling pathway in the metastasis of lung cancer cells, establishing YES1 as a promising target for suppression of metastasis. This paper unveils a novel inhibitor that effectively targets both RET and YES1, thereby demonstrating its potential to impede the growth and metastasis of RET rearrangement lung cancer.

LncRNA12097.1 contributes to endometrial cell growth by enhancing YES1 activating ß-catenin via sponging miR-145-5p.

Despite previous investigations elucidating the regulatory mechanisms of long non-coding RNAs (lncRNAs) in endometrial function and reproductive disorders, the precise pathways through which lncRNAs impact endometrial functions and fertility remain unclear. In this study, we performed an expression profile analysis of lncRNAs in the endometrial tissue of Hu sheep with different prolificacy, identifying 13,707 lncRNAs. We discovered a bidirectional lncRNA, designated lncRNA12097.1, exhibiting significant up-regulation exclusively in the endometrium of Hu sheep with high fecundity. Functional analyses revealed lncRNA12097.1 significantly enhanced proliferation and cell cycle progression in both endometrial epithelial cell (EEC) and stromal cells (ESC), while inhibiting apoptosis in these cell types. Mechanistically, we demonstrated a directly interaction between lncRNA12097.1 and miR-145-5p, with YES proto-oncogene 1 (YES1) being identified as a validated target of miR-145-5p. Interference with lncRNA12097.1 resulted in suppressed cell growth through down-regulation of YES1 expression, which could be rescued by miR-145-5p. Furthermore, lncRNA12097.1 functions as a competitive endogenous RNA (ceRNA) for miR-145-5p in ESCs, sequestering miR-145-5p and preventing its binding to the 3'UTR of YES1 mRNA. This interaction led to increased expression of YES1 and subsequent activation of downstream ß-catenin signaling, thereby promoting ESC growth in Hu sheep. These findings provide novel molecular insights into the mechanisms underlying prolificacy in sheep.

Role of YES1 signaling in tumor therapy resistance.

YES proto-oncogene 1 (YES1) is an SRC family kinase (SFK) that plays a key role in cancer cell proliferation, adhesion, invasion, survival, and angiogenesis during tumorigenesis and tumor development. Reports suggest that YES1 amplification is associated with resistance to chemotherapeutic drugs and tyrosine kinase inhibitors (TKIs) in human malignancies. However, the mechanisms of drug resistance have not been fully elucidated. In this article, we review the literature on YES1 and discuss the implications of YES1 signaling for targeted therapy and chemotherapy resistance in malignancies. Moreover, recent advances in targeted therapy for YES1-amplified malignancies are summarized. Finally, we conclude that targeting YES1 may reverse drug resistance and serve as a valuable tumor treatment strategy.

GALNT12 promotes fibrosarcoma growth by accelerating YAP1 nuclear localization.

Fibrosarcoma is a highly malignant type of soft tissue sarcoma that currently lacks effective treatment options. Polypeptide N-acetylgalactosaminyltransferase 12 (GALNT12) belongs to the uridine diphosphate N-acetylgalactosamine gene family, which is involved in numerous biological processes of diseases, such as tumor progression. Its upregulated expression is closely associated with the development of colorectal cancer. However, research on the role of GALNT12 in fibrosarcoma is currently limited. The present study aimed to assess the expression and biological function of GALNT12 in fibrosarcoma. Patient data and tissue samples were collected and public datasets were obtained from the Gene Expression Omnibus (GSE24369 and GSE21124). Immunofluorescence assays were performed to observe the cellular localization of GALNT12. GALNT12 expression was measured using reverse transcription-quantitative PCR, western blotting and immunohistochemistry. Small interfering RNAs were constructed to knock down GALNT12 expression in HT-1080 cells. Cell Counting Kit-8 and EdU assays were used to assess fibrosarcoma cell proliferation. Wound healing and Transwell assays were used to detect migration. Gene set enrichment analysis was performed to identify key pathways. Paired and unpaired Student's t-test, Fisher's exact test and one-way ANOVA (followed by Tukey's Honest Significant Difference test) were used to analyze the data. It was demonstrated that GALNT12 expression was upregulated in both fibrosarcoma cell lines and tissue samples and predicted poor patient prognosis. In vitro experiments demonstrated that high GALNT12 expression levels significantly increased HT-1080 cell proliferation and migration. Furthermore, it was demonstrated that high GALNT12 expression levels were closely associated with the yes1 associated transcriptional regulator (YAP1) signaling pathway. Knockdown of GALNT12 inhibited YAP1 nuclear translocation, which affected activation of key downstream genes including AMOTL2, BIRC5 and CYR61. Therefore, the present study demonstrated that GALNT12 promoted fibrosarcoma progression. GALNT12 could be a potential biomarker for this disease and may potentially provide new ideas for targeted therapy of fibrosarcoma in the future.

Identification of signature genes and drug candidates for primary plasma cell leukemia: An integrated system biology approach.

BACKGROUND: Plasma cell leukemia (PCL) is one of the rare cancer which is characterized by the uncontrolled proliferation of plasma cells in peripheral blood and bone marrow. The aggressive behavior of the disease and high mortality rate among PCL patients makes it a thirst area to be explored. METHODS: The dataset for PCL was obtained from the GEO database and was analyzed using GEO2R for differentially expressed genes. Further, the functional enrichment analysis was carried out for DEGs using DAVID. The protein-protein interactions (PPI) for DEGs were obtained using STRING 11.5 and were analyzed in Cytoscape 3.7.2. to obtain the key hub genes. These key hub genes were investigated for their interaction with suitable drug candidates using DGIdb, DrugMAP, and Schrodinger's version 2022-1. RESULTS: Out of the total of 104 DEGs, 39 genes were up-regulated whereas 65 genes were down-regulated. A total of 11 biological processes, 2 cellular components, and 5 molecular functions were enriched along with the 7 KEGG pathways for the DEGs. Further, a total of 11 hub genes were obtained from the PPI of DEGs of which TP53, MAPK1, SOCS1, MBD3, and YES1 were the key hub genes. Oxaliplatin, mitoxantrone, and ponatinib were found to have the highest binding affinity towards the p53, MAPK1, and YES1 proteins respectively. CONCLUSION: TP53, MAPK1, SOCS1, MBD3, and YES1 are the signature hub genes that might be responsible for the aggressive prognosis of PCL leading to poor survival rate. However, p53, MAPK1, and YES1 can be targeted with oxaliplatin, mitoxantrone, and ponatinib.

Downregulation of circ-YES1 suppresses NSCLC migration and proliferation through the miR-142-3p-HMGB1 axis.

BACKGROUND: Circular RNAs (circRNAs) are a new family of abundant regulatory RNAs with roles in various types of cancer. While the hsa_circ_0046701 (circ-YES1) function in non-small cell lung cancer (NSCLC) is unclear. METHODS: Circ-YES1 expression in normal pulmonary epithelial and NSCLC cells was examined. The small interfering RNA for circ-YES1 was prepared, cell proliferation and migration were assessed. Tumorigenesis in nude mice was assayed to validate the role of circ-YES1. Bioinformatics analyses and luciferase reporter assays were utilized to identify downstream targets of circ-YES1. RESULTS: Compared to normal pulmonary epithelial cells, the circ-YES1 expression increased in NSCLC cells, and cell proliferation and migration were suppressed after circ-YES1 knockdown. Both high mobility group protein B1 (HMGB1) and miR-142-3p were found to be downstream targets of circ-YES1, and miR-142-3p inhibition and HMGB1 overexpression reversed the effects of circ-YES1 knockdown on cell proliferation and migration. Similarly, HMGB1 overexpression reversed the miR-142-3p overexpression effects on these two processes. The imaging experiment results revealed that circ-YES1 knockdown impeded tumor development and metastasis in a nude mouse xenograft model. CONCLUSION: Taken together, our results show that circ-YES1 promotes tumor development through the miR-142-3p-HMGB1 axis and support the development of circ-YES1 probability as a new therapeutic NSCLC target.

Knockdown of kinesin family member 4A inhibits cell proliferation, migration, and invasion while promoting apoptosis of urothelial bladder carcinoma cells.

BACKGROUND: Kinesin family member 4A (KIF4A) is upregulated in a variety of cancers. However, its expression and potential downstream targets in urothelial bladder carcinoma (UBC) remain unclear. METHODS: Expression data of KIF4A in UBC and noncancerous tissues were downloaded from the GEPIA database. Cell proliferation, migration, invasion, and apoptosis of T24 and 5637 UBC cells were examined using wound healing, transwell, colony formation, CCK-8, and flow cytometry assays. KIF4A and potential downstream genes were analyzed using qRT-PCR, western blot analysis, and immunohistochemistry. RESULTS: In UBC samples, KIF4A expression was significantly higher than in corresponding noncancerous samples. UBC patients with high KIF4A expression had poor cancer-specific survival and overall survival. Knockdown of KIF4A significantly inhibited proliferation and promoted apoptosis of UBC cells, accompanied by dephosphorylation of AKT and increased the protein level of proapoptotic factors. Additionally, knockdown of KIF4A reduced migration and invasion of UBC cells whereas overexpression of KIF4A exhibited opposite effects, along with altered protein level in epithelial-mesenchymal transition-related genes. Furthermore, overexpression of YAP1 promoted KIF4A expression whereas knockdown of YAP1 suppressed KIF4A expression in UBC cells. Alternatively, KIF4A knockdown reduced YAP1 nuclear protein level whereas KIF4A overexpression suppressed YAP1 phosphorylation and facilitated YAP1 nuclear translocation. CONCLUSIONS: KIF4A upregulation correlates with poor prognosis of UBC. Knockdown of KIF4A inhibits proliferation, migration, and invasion of UBC cells while inducing apoptosis possibly through dephosphorylation of AKT, changes in EMT-related genes, and interaction with YAP1.

YAP1-MAML2 fusion in a pediatric NF2-wildtype intraparenchymal brainstem schwannoma.

Biallelic inactivation of NF2 represents the primary or sole oncogenic driver event in the vast majority of schwannomas. We report on a four-year-old female who underwent subtotal resection of a right medullary intraparenchymal schwannoma. RNA sequencing revealed an in-frame fusion between exon 5 of YAP1 and exon 2 of MAML2. YAP1-MAML2 fusions have previously been reported in a variety of tumor types, but not schwannomas. Our report expands the spectrum of oncogenic YAP1 gene fusions an alternative to NF2 inactivation to include sporadic schwannoma, analogous to what has recently been described in NF2-wildtype pediatric meningiomas. Appropriate somatic and germline molecular testing should be undertaken in all young patients with solitary schwannoma and meningioma given the high prevalence of an underlying tumor predisposition syndrome. In such patients, the identification of a somatic non-NF2 driver alteration such as this newly described YAP1 fusion, can help ascertain the diagnosis of a sporadic schwannoma.

YES1 Is a Druggable Oncogenic Target in SCLC.

INTRODUCTION: SCLC is an extremely aggressive subtype of lung cancer without approved targeted therapies. Here we identified YES1 as a novel targetable oncogene driving SCLC maintenance and metastasis. METHODS: Association between YES1 levels and prognosis was evaluated in SCLC clinical samples. In vitro functional experiments for proliferation, apoptosis, cell cycle, and cytotoxicity were performed. Genetic and pharmacologic inhibition of YES1 was evaluated in vivo in cell- and patient-derived xenografts and metastasis. YES1 levels were evaluated in mouse and patient plasma-derived exosomes. RESULTS: Overexpression or gain/amplification of YES1 was identified in 31% and 26% of cases, respectively, across molecular subgroups, and was found as an independent predictor of poor prognosis. Genetic depletion of YES1 dramatically reduced cell proliferation, three-dimensional organoid formation, tumor growth, and distant metastasis, leading to extensive apoptosis and tumor regressions. Mechanistically, YES1-inhibited cells revealed alterations in the replisome and DNA repair processes, that conferred sensitivity to irradiation. Pharmacologic blockade with the novel YES1 inhibitor CH6953755 or dasatinib induced marked antitumor activity in organoid models and cell- and patient-derived xenografts. YES1 protein was detected in plasma exosomes from patients and mouse models, with levels matching those of tumors, suggesting that circulating YES1 could represent a biomarker for patient selection/monitoring. CONCLUSIONS: Our results provide evidence that YES1 is a new druggable oncogenic target and biomarker to advance the clinical management of a subpopulation of patients with SCLC.

Circ_0081143 Contributes to Gastric Cancer Malignant Development and Doxorubicin Resistance by Elevating the Expression of YES1 by Targeting mziR-129-2-3p.

Background/Aims: The increased mortality of gastric cancer (GC) is mainly attributed to the development of chemoresistance. Circular RNAs, as the novel type of biomarkers in GC, have attracted wide attention. The purpose of this study was to investigate the functional role of circ_0081143 in GC with doxorubicin (DR) resistance and its potential action mechanism. Methods: The expression of circ_0081143, miR-129-2-3p and YES proto-oncogene 1 (YES1) in GC tissues and cells was measured by quantitative real-time polymerase chain reaction. The half maximal inhibitory concentration value was calculated based on the MTT cell viability assay. Cell proliferation and apoptosis were monitored by MTT and flow cytometry assays. Transwell assays were employed to check cell migration and invasion. The protein levels of YES1 and apoptosis-related proteins were detected by western blotting. The interaction between miR-129-2-3p and circ_0081143 or YES1 was verified by dual-luciferase reporter and pull-down assays. A tumorigenicity assay was conducted to verify the role of circ_0081143 in vivo. Results: Circ_0081143 was highly expressed in DR-resistant GC tumor tissues and cells. Depletion of circ_0081143 reduced DR resistance and inhibited DR-resistant GC cell proliferation, migration and invasion. Circ_0081143 targeted miR-129-2-3p and inhibited the role of miR-129-2-3p. In addition, YES1 was a target of miR-129-2-3p, and its function was suppressed by miR-129-2-3p. Importantly, circ_0081143 positively modulated the expression of YES1 through mediating miR-129-2-3p. Circ_0081143 knockdown weakened the DR-resistant GC tumor growth in vivo. Conclusions: Circ_0081143 knockdown weakened DR resistance and blocked the development of DR-resistant GC by regulating the miR-129-2-3p/YES1 axis. Our data suggest that circ_0081143 is a promising target for the treatment of GC with DR resistance.

Bioactive Phytoconstituents as Potent Inhibitors of Tyrosine-Protein Kinase Yes (YES1): Implications in Anticancer Therapeutics.

Tyrosine-protein kinase Yes (YES1) belongs to the Tyrosine-protein kinase family and is involved in several biological activities, including cell survival, cell-cell adhesion, cell differentiation, and cytoskeleton remodeling. It is highly expressed in esophageal, lung, and bladder cancers, and thus considered as an attractive drug target for cancer therapy. In this study, we performed a virtual screening of phytoconstituents from the IMPPAT database to identify potential inhibitors of YES1. Initially, the molecules were retrieved on their physicochemical properties following the Lipinski rule of five. Then binding affinities calculation, PAINS filter, ADMET, and PASS analyses followed by an interaction analysis to select safe and clinically better hits. Finally, two compounds, Glabrene and Lupinisoflavone C (LIC), with appreciable affinities and a specific interaction towards the AlphaFold predicted structure of YES1, were identified. Their time-evolution analyses were carried out using an all-atom molecular dynamics (MD) simulation, principal component analysis, and free energy landscapes. Altogether, we propose that Glabrene and LIC can be further explored in clinical settings to develop anticancer therapeutics targeting YES1 kinase.

YES1 and MYC Amplifications as Synergistic Resistance Mechanisms to Different Generation ALK Tyrosine Kinase Inhibitors in Advanced NSCLC: Brief Report of Clinical and Preclinical Proofs.

INTRODUCTION: ALK tyrosine kinase inhibitors (TKIs) are the standard treatment for advanced ALK-positive NSCLC. Nevertheless, drug resistance inevitably occurs. Here, we report a case of a patient with metastatic ALK-positive lung adenocarcinoma with an impressive resistance to sequential treatment with ALK TKIs mediated by YES1 and MYC amplification in a contest of epithelial-to-mesenchymal transition and high progressive chromosomal instability. METHODS: The patient received, after chemotherapy and 7 months of crizotinib, brigatinib and lorlatinib with no clinical benefit to both treatments. A study of resistance mechanisms was performed with whole exome sequencing on different biological samples; primary cell lines were established from pleural effusion after lorlatinib progression. RESULTS: At whole exome sequencing analysis, YES1 and MYC amplifications were observed both in the pericardial biopsy and the pleural effusion samples collected at brigatinib and lorlatinib progression, respectively. Increasing chromosomal instability from diagnostic biopsy to pleural effusion was also observed. The addition of dasatinib to brigatinib or lorlatinib restored the sensitivity in primary cell lines; data were confirmed also in H3122_ALK-positive model overexpressing both YES1 and MYC. CONCLUSIONS: In conclusion, YES1 and MYC amplifications are candidates to justify a rapid acquired resistance to crizotinib entailing primary brigatinib and lorlatinib resistance. In this context, a combination strategy of ALK TKI with dasatinib could be effective to overcome a rapid resistance.

miR-133a targets YES1 to reduce cisplatin resistance in ovarian cancer by regulating cell autophagy.

BACKGROUND: Accumulating evidence has revealed that aberrant microRNA (miRNA) expression can affect the development of chemotherapy drug resistance by modulating the expression of relevant target proteins. Emerging evidence has demonstrated that miR-133a participates in the tumorigenesis of various cancers. However, whether miR-133a is associated with cisplatin resistance in ovarian cancer remains unclear. OBJECTIVE: To investigate the role of miR-133a in the development of cisplatin resistance in ovarian cancer. METHODS: MiR-133a expression in cisplatin-resistant ovarian cancer cell lines was assessed by reverse-transcription quantitative PCR (RT-qPCR). A cell counting kit-8 (CCK-8) assay was used to evaluate the viability of tumour cells treated with cisplatin in the presence or absence of miR-133a. A luciferase reporter assay was used to analyse the binding of miR-133a with the 3' untranslated region (3'UTR) of YES proto-oncogene 1 (YES1). The YES1 expression level was analysed using a dataset from the International Cancer Genome Consortium (ICGC) and assessed by RT-qPCR and western blotting in vitro. The roles and mechanisms of YES1 in cell functions were further probed via gain- and loss-of-function analysis. RESULTS: The expression of miR-133a was significantly decreased in cisplatin-resistant ovarian cancer cell lines (A2780-DDP and SKOV3-DDP), and the overexpression of the miR-133a mimic reduced cisplatin resistance in A2780-DDP and SKOV3-DDP cells. Treatment with the miR-133a inhibitor increased cisplatin sensitivity in normal A2780 and SKOV3 cells. MiR-133a binds the 3'UTR of YES1 and downregulates its expression. Bioinformatics analysis revealed that YES1 expression was upregulated in recurrent cisplatin-resistant ovarian cancer tissue, and in vitro experiments also verified its upregulation in cisplatin-resistant cell lines. Furthermore, we discovered that miR-133a downregulated the expression of YES1 and thus inhibited cell autophagy to reduce cisplatin resistance. Yes1 knockdown significantly suppressed the cisplatin resistance of ovarian cancer cells by inhibiting autophagy in vitro. Xenograft tumour implantation further demonstrated that Yes1 overexpression promoted ovarian tumour development and cisplatin resistance. CONCLUSIONS: Our results suggest that the miR-133a/YES1 axis plays a critical role in cisplatin resistance in human ovarian cancer by regulating cell autophagy, which might serve as a promising therapeutic target for ovarian cancer chemotherapy treatment in the future.

YES1 as a Therapeutic Target for HER2-Positive Breast Cancer after Trastuzumab and Trastuzumab-Emtansine (T-DM1) Resistance Development.

Trastuzumab-emtansine (T-DM1) is a therapeutic agent molecularly targeting human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC), and it is especially effective for MBC with resistance to trastuzumab. Although several reports have described T-DM1 resistance, few have examined the mechanism underlying T-DM1 resistance after the development of acquired resistance to trastuzumab. We previously reported that YES1, a member of the Src family, plays an important role in acquired resistance to trastuzumab in HER2-amplified breast cancer cells. We newly established a trastuzumab/T-DM1-dual-resistant cell line and analyzed the resistance mechanisms in this cell line. At first, the T-DM1 effectively inhibited the YES1-amplified trastuzumab-resistant cell line, but resistance to T-DM1 gradually developed. YES1 amplification was further enhanced after acquired resistance to T-DM1 became apparent, and the knockdown of the YES1 or the administration of the Src inhibitor dasatinib restored sensitivity to T-DM1. Our results indicate that YES1 is also strongly associated with T-DM1 resistance after the development of acquired resistance to trastuzumab, and the continuous inhibition of YES1 is important for overcoming resistance to T-DM1.

YAP activation attenuates toxicarioside G­induced lethal autophagy arrest in SW480 colorectal cancer cells.

Toxicarioside G (TCG), a natural product isolated from Calotropis gigantea, has been found to exhibit potent anticancer effects. The present study aimed to investigate the effect of TCG on the SW480 colorectal cancer cell line and the role of autophagy and Yes1 associated transcriptional regulator (YAP) in the TCG­mediated inhibition of cell proliferation and viability. Cell proliferation was detected using MTT, BrdU, colony formation and LDH release assays, while apoptosis was analyzed using flow cytometry and western blot analyses. Immunofluorescence and western blot analysis was used to determine TCG­induced autophagy and YAP activation. Pharmacological inhibition and siRNA was used to investigate the role of autophagy and YAP in TCG­mediated cell growth inhibition. The results revealed that TCG inhibited SW480 cell proliferation and viability, independent of apoptosis, and also induced autophagy. It was further demonstrated that TCG blocks autophagic flux, resulting in autophagy arrest in the SW480 cell line. The inhibition of autophagy restored the TCG­mediated inhibition of cell proliferation and viability, suggesting that TCG may induce lethal autophagy arrest in the SW480 cell line. Furthermore, TCG induced YAP activation in the SW480 cell line. Inhibition of YAP activity enhanced the TCG­mediated inhibition of cell proliferation and viability, suggesting that YAP may play a protective role in the TCG­induced effects. In conclusion, the findings of the present study indicated that TCG may induce lethal autophagy arrest and activate YAP, which serves a protective role in the SW480 cell line. These results suggested that the combined targeting of TCG and YAP may represent a promising strategy for TCG­mediated anticancer therapy.