Xenograft Tumor Growth Research Articles

METTL1 coordinates cutaneous squamous cell carcinoma progression via the m7G modification of the ATF4 mRNA

Methyltransferase-like 1 (METTL1)-mediated m7G modification is a common occurrence in various RNA species, including mRNAs, tRNAs, rRNAs, and miRNAs. Recent evidence suggests that this modification is linked to the development of several cancers, making it a promising target for cancer therapy. However, the specific role of m7G modification in cutaneous squamous cell carcinoma (cSCC) is not well understood. In this study, we observed conspicuously elevated levels of METTL1 in cSCC tumors and cell lines. Inhibiting METTL1 led to reduced survival, migration, invasion, and xenograft tumor growth in cSCC cells. Mechanistically, through a combination of RNA sequencing, m7G methylated immunoprecipitation (MeRIP)-qPCR, and mRNA stability assays, we discovered that METTL1 is responsible for the m7G modification of ATF4 mRNA, leading to increased expression of ATF4. Importantly, we demonstrated that this modification is dependent on the methyltransferase activity of METTL1. Additionally, we observed a positive association between ATF4 expression and METTL1 levels in cSCC tumors. Intriguingly, restoring ATF4 expression in cSCC cells not only promoted glycolysis but also reversed the anti-tumor effects of METTL1 knockdown. In conclusion, our results underscore the critical role of METTL1 and m7G modification in cSCC tumorigenesis, suggesting a promising target for future cSCC therapies.

Proteomic Profiling of Medullary Thyroid Cancer Identifies CAPN1 as a Key Regulator of NF1 and RET Fueled Growth.

Background: Medullary thyroid cancer (MTC) is a frequently metastatic tumor of the thyroid that develops from the malignant transformation of C-cells. These tumors most commonly have activating mutations within the RET or RAS proto-oncogenes. Germline mutations within RET result in C-cell hyperplasia, and cause the MTC pre-disposition disorder, multiple endocrine neoplasia, type 2A (MEN2A). Single-agent therapies for MTC, including vandetanib (VAN) and cabozantinib for all MTCs and selpercatinib (SEL) for RET-mutated MTC, lead to partial responses but are not curative. Methods: To identify new therapeutic targets for MTC, we conducted proteomic profiling of normal C-cells, MTC cells, pre-malignant MEN2A patient samples, and MTC tumors. Results: From this analysis, we identified CAPN1, a member of the CALPAIN (CAPN) family endopeptidases, as widely upregulated in MTC samples. We found that short hairpin RNA-mediated depletion of CAPN1 or inhibitors of CAPN1 significantly reduced MTC cell growth, colony formation, and xenograft tumor growth invivo. In addition, we show that CAPN1 inhibitors synergize with VAN and SEL in vitro, maximizing apoptosis. Mechanistic experiments implicate CAPN1 in inhibiting neurofibromin, encoded by NF1, and CAPN1 inhibitors stabilize NF1 protein levels and diminish downstream RAS/RET activation of AKT and ERK. Conclusions: Our data suggest that increased CAPN1 levels support RET and RAS-fueled growth by reducing NF1 levels. We find that combinatorial therapies between CAPN1 inhibitors and VAN or SEL show maximal efficacy in MTC cells.

Mutant KRAS and CK2 Cooperatively Stimulate SLC16A3 Activity to Drive Intrahepatic Cholangiocarcinoma Progression.

Intrahepatic cholangiocarcinoma (iCCA) is a lethal malignancy affecting the liver and biliary system. Enhanced understanding of the pathogenic mechanisms underlying iCCA tumorigenesis and the discovery of appropriate therapeutic targets are imperative to improve patient outcomes. Here, we investigated the functions and regulations of solute carrier family 16 member 3 (SLC16A3), which has been reported to be a biomarker of poor prognosis in iCCA. High SLC16A3 expression was enriched in KRAS-mutated iCCA tumors, and mutant KRAS elevated SLC16A3 expression via the PI3K/AKT/mTORC1/HIF1α pathway. SLC16A3 not only enhanced glycolysis but also induced epigenetic reprogramming to regulate iCCA progression. Phosphorylation of SLC16A3 at S436 (p-S436) was vital for its oncogenic function and was linked to iCCA progression. Casein kinase 2 (CK2) directly phosphorylated SLC16A3 at S436, and CK2 inhibition with CX-4945 (silmitasertib) reduced the growth of KRAS-mutated iCCA tumor xenografts and patient-derived organoids. Together, this study provides valuable insights into the diverse functions of SLC16A3 in iCCA and comprehensively elucidates the upstream regulatory mechanisms, providing potential therapeutic strategies for iCCA patients with KRAS mutations.

Discovery of N-(1,2,4-Thiadiazol-5-yl)benzo[b]oxepine-4-carboxamide Derivatives as Novel Antiresistance Androgen Receptor Antagonists.

The ligand-binding pocket of the androgen receptor (AR) is the targeting site of all clinically used AR antagonists. However, various drug-resistant mutations emerged in the pocket. We previously reported a new targeting site at the dimer interface of AR (dimer interface pocket) and identified a novel antagonist M17-B15 that failed in oral administration. In this study, the head part of M17-B15 was substituted with divergent structures. Potent antagonist Z10 with benzo[b]oxepine was first identified. Subsequent structural optimization on the 2-oxopropyl moiety of Z10 generated the more powerful Y5 (IC50 = 0.04 μM). Out of the ordinary, Y5 demonstrated dual mechanisms of action, antagonized AR by disrupting AR dimerization, and induced AR degradation via the ubiquitin-proteasome pathway. Furthermore, Y5 exhibited excellent activity against variant drug-resistant AR mutants comparable to recently approved darolutamide. Furthermore, Y5 effectively suppressed the tumor growth of the LNCaP xenograft via oral administration, providing a potential novel therapeutic for drug-resistant prostate cancer.

Mesenchymal stem cell-mediated adipogenic transformation: a key driver of oral squamous cell carcinoma progression

BackgroundInteraction between mesenchymal stem cells (MSCs) and oral squamous cell carcinoma (OSCC) cells plays a major role in OSCC progression. However, little is known about adipogenic differentiation alteration in OSCC-derived MSCs (OSCC-MSCs) and how these alterations affect OSCC growth.MethodsMSCs were successfully isolated and cultured from normal gingival tissue, OSCC peritumoral tissue, and OSCC tissue. This included gingiva-derived MSCs (GMSCs), OSCC adjacent noncancerous tissues-derived MSCs (OSCCN-MSCs), and OSCC-MSCs. The adipogenic and osteogenic differentiation capabilities of these cells were evaluated using Oil Red O and Alizarin Red S staining, respectively. OSCC cells were then co-cultured with either OSCC-MSCs or GMSCs to assess the impact on OSCC cell proliferation and migration. Subcutaneous xenograft experiments were conducted in BALB/c-nu mice to further investigate the effects in vivo. Additionally, immunohistochemical staining was performed on clinical samples to determine the expression levels of fatty acid synthase (FASN) and the proliferation marker Ki67.ResultsOSCC-MSCs exhibited enhanced adipogenic differentiation and reduced osteogenic differentiation compared to GMSCs. OSCC-MSCs significantly increased the proliferation and migration of OSCC cells relative to GMSCs and promoted tumor growth in mouse xenografts. Lipid droplet accumulation in the stroma was significantly more pronounced in OSCC + OSCC-MSCs xenografts compared to OSCC + GMSCs xenografts. Free fatty acids (FFAs) levels were elevated in OSCC tissues compared to normal gingival tissues. Moreover, OSCC-MSCs consistently secreted higher levels of FFAs in condition medium than GMSCs. Knockdown of FASN in OSCC-MSCs reduced their adipogenic potential and inhibited their ability to promote OSCC cell proliferation and migration. Clinical sample analysis confirmed higher FASN expression in OSCC stroma, correlating with larger tumor size and increased Ki67 expression in cancer tissues, and was associated with poorer overall survival.ConclusionsOSCC-MSCs promoted OSCC proliferation and migration by upregulating FASN expression and facilitating FFAs secretion. Our results provide new insight into the mechanism of OSCC progression and suggest that the FASN of OSCC-MSCs may be potential targets of OSCC in the future.

Inhibition of Renal Cell Carcinoma Growth by 1,3-thiazin-6-one Through Targeting the Inflammatory Reaction.

The current study examined the underlying mechanism and the effect of 1,3-thiazin-6-one on the growth of renal cancer. The findings showed that 1,3-thiazin-6-one treatment inhibited the growth of xenograft tumors in a dose-dependent manner in mice model of renal cancer. Furthermore, when 1,3-thiazin-6-one was administered in a dose-dependent manner to mice with renal cancer, the expression of the proteins p-PI3K and p-Akt significantly decreased. In mice model of renal cancer, 1,3-thiazin-6-one treatment also inhibited p-mTOR expression. In a model of renal cancer in mice, the 1,3-thiazin-6-one therapy specifically targeted the expression of nuclear factor κB (NF κB) and signal transducer and activator of transcription 3 (STAT3). Renal cancer cells' vitality was significantly (p < 0.05) reduced in a dose-dependent manner upon exposure to 1,3-thiazin-6-one. It also prevents invasiveness of the renal cancer cells in addition to suppression of colony forming potential. In summary, the 1,3-thiazin-6-one blocks the growth of kidney cancer by focusing on the pathways that trigger the inflammatory cascade. Therefore, 1,3-thiazin-6-one might be developed as a significant medicinal agent to cure renal cancer.

KGF impedes TRIM21-enhanced stabilization of keratin 10 mediating differentiation in hypopharyngeal cancer.

KGF, also known as FGF7, is a member of the fibroblast growth factor (FGF) family that binds with high affinity to the FGF receptor 2b (FGFR2b) and regulates various cellular processes, including cell proliferation and differentiation in a variety of tumors. However, its potential role in hypopharyngeal cancer (HPC) remains largely unknown. In our study, we observed increased expression of FGFR2b in HPC. KGF treatment inhibited the expression of the differentiation marker keratin 10 (K10) protein at the post-transcriptional level in FaDu cells. Furthermore, treatment with the proteasome inhibitor MG132 was found to attenuate KGF-induced K10 reduction, suggesting the involvement of the ubiquitin-proteasome system. Using mass spectrometry and immunoprecipitation analysis, we identified the E3 ubiquitin ligase TRIM21 as a K10-interacting protein. Unexpectedly, instead of causing degradation, TRIM21 enhanced K10 protein stability through K6-linked ubiquitination of K10 at lysine 163 (K163) in the context of KGF exposure. Meanwhile, KGF treatment decreased TRIM21 protein levels, which were regulated by the p38 MAPK pathway, leading to K48-linked ubiquitination-mediated degradation of TRIM21. Notably, TRIM21 knockdown significantly promoted proliferation, inhibited differentiation and migration of FaDu cells, whereas TRIM21 overexpression had opposite effects in vitro and suppressed xenograft tumor growth in vivo. Our study demonstrates that TRIM21 may act as a tumor suppressor in HPC. However, TRIM21 overexpression decreased the sensitivity of FaDu cells to 5-fluorouracil, whereas TRIM21 knockdown or KGF administration significantly increased 5-fluorouracil sensitivity. Taken together, these findings highlight the intricate balance between protein stabilization and degradation orchestrated by KGF. This ubiquitination-mediated non-degradation mechanism of TRIM21 may provide novel therapeutic strategies for HPC and other cancers.

Exosomes derived from FN14-overexpressing BMSCs activate the NF-κB signaling pathway to induce PANoptosis in osteosarcoma.

Despite advances in treatment, the prognosis of osteosarcoma (OS) patients is unsatisfactory, and searching for possible targets is substantial. Fibroblast growth factor inducible type 14 (FN14), a plasma membrane protein, is involved in wound healing, angiogenesis, proliferation, apoptosis, and inflammation. However, its implication in OS development and progression has not been completely characterized. Herein, we explored the cell-to-cell communication of bone marrow mesenchymal stem cells (BMSCs) and OS cells mediated by FN14 in the tumor microenvironment of OS. To assess the interplay between FN14 expression levels and patient survival, FN14 expression was measured in both normal and OS tissues. The FN14 overexpressing BMSCs (OE) were constructed using lentivirus, and exosomes (EXO) were extracted. The uptake of FN14-containing EXO by OS cells was analyzed via flow cytometry and in vivo fluorescence imaging. In addition, high-throughput sequencing was performed to analyze the mechanisms by which EXO inhibits OS cell growth. Finally, the therapeutic effect of OE-EXO was evaluated in a mouse model of OS xenografts. The results showcased reduced FN14 expression in human and mouse OS tissues, suggesting its role may be involved in the malignant progression of OS. The FN14 expression was higher in BMSCs relative to OS cells, and FN14 was secreted and excreted by EXO. The OS cell progression was suppressed after the uptake of FN14-derived EXO from BMSCs. In addition, RNA sequencing revealed that FN14 in EXO activated NF-κB signaling, triggering PANoptosis in OS cells. In vivo, OE-EXO injection inhibited tumor growth in OS xenografts and significantly improved the long-term survival of mice. Our findings suggest that FN14 carried by EXO from BMSCs activates the NF-κB pathway to trigger PANoptosis in OS cells, providing a potential therapeutic strategy to inhibit OS progression.

YAP1 is a prognostic marker and its inhibition reduces tumor progression in adrenocortical tumors.

Adrenocortical cancer (ACC) is rare and aggressive, with YAP1 overexpression associated with poor outcomes in pediatric patients. In this study, we investigated the mechanisms by which YAP1 drives ACC progression and explored it as a potential target therapy. YAP1 expression and methylation in ACC were analyzed from pediatric and adult cohorts. The role of YAP1 on ACC progression was examined in vitro using an adrenocortical cell line. Also, was evaluated the YAP1's influence on beta-catenin. The effect of YAP1 pharmacological inhibition was assessed on tumor growth in a murine xenograft model of ACC. High YAP1 expression was associated with lower survival in all cohorts. YAP1 methylation signature associated with patients' prognosis. The inhibition of YAP1 reduced ACC cell viability through cell cycle arrest in the G0-G1 phase, inhibited the epithelial-mesenchymal transition, and cell invasion. YAP1 modulated beta-catenin protein levels and transcription activity, whereas beta-catenin partially mediated the effect of YAP1 on adrenocortical tumorigenesis. In vivo, verteporfin impaired tumor growth and Ki67 immunoreactivity in xenografts. YAP1 is a potential novel prognostic marker in ACC patients. Its deregulation contributes to adrenocortical tumorigenesis partially through crosstalk between Hippo/YAP1 and Wnt/beta-catenin pathways. YAP1 inhibition is a new antitumor target.

RNF138 contributes to cisplatin resistance in nasopharyngeal carcinoma cells

Resistance to chemotherapy is a significant concern in the treatment of nasopharyngeal carcinoma (NPC), and occurs due to various mechanisms. This study is aimed to evaluate the effects of RING finger protein 138 (RNF138) in the development of cisplatin resistance to NPC. After gene overexpression and silencing, the expression levels of RNF138 were evaluated. The impacts of RNF138 on the proliferation and apoptosis rate of NPC cells were then assessed. γ-H2AX-mediated DNA damage was determined via immunofluorescence assay. Moreover, a tumor xenograft mouse model was developed to investigate the role of RNF138 on NPC progression in vivo. Additionally, transcriptome analysis was performed in 5–8 F cells transfection with OE-RNF1138 or OE-NC.Cisplatin significantly inhibited the proliferation, and promoted apoptosis and DNA damage in NPC cells; however, overexpression of RNF138 reversed the aforementioned regulatory role of cisplatin on NPC cells. Knockdown of RNF138 resulted in contrasting phenotypic outcomes. Additionally, in nude mice, RNF138 overexpression attenuated the suppressive effects of cisplatin on the growth of xenograft tumor, while RNF138 silencing further enhanced the inhibiting role of cisplatin. We further indicated that in 5–8 F cells following RNF138 overexpression, some pathways such as PI3K-Akt signaling pathway, human papillomavirus infection and ErbB signaling pathway that have been reported to be associated with NPC progression and cisplatin resistance were significantly enriched. These findings indicate that the modulation of RNF138 could potentially address the issue of chemotherapy failure by overcoming cisplatin resistance in NPC cells, making it a promising candidate for targeted drug therapy.

AURKA/PLK1/CDC25C Axis as a Novel Therapeutic Target in INI1-Deficient Epithelioid Sarcoma.

Effective therapeutic strategies for epithelioid sarcoma (EpS), a high-grade soft tissue sarcoma characterized by loss of integrase interactor 1 (INI1), have not yet been developed. The present study therefore investigated the association between INI1 loss and upregulation of the aurora kinase A (AURKA)/polo-like kinase 1 (PLK1)/cell division cycle 25C (CDC25C) axis, as well as the therapeutic relevance of this axis in EpS. Notably, our findings showed that the reintroduction of INI1 in VA-ES-BJ cells significantly reduced proliferation, mitigated tumorigenicity, and negatively regulated the expression of AURKA and its downstream effectors, as well as the activation of PLK1 and CDC25C. These results suggest that INI1 deficiency enhanced EpS growth by upregulating the AURKA/PLK1/CDC25C axis. AURKA silencing using siRNAs inhibited VA-ES-BJ and Asra-EPS cell proliferation by inactivating PLK1 and CDC25C. Alisertib, a selective AURKA inhibitor, exerted markedly greater antiproliferative effects on EpS cells than on normal human dermal fibroblasts, and these effects were dependent on INI1 deficiency. Inhibition of AURKA activity by alisertib induced G2/M cell cycle arrest and apoptosis via the inactivation of AURKA downstream effectors in EpS cells. Alisertib also significantly decreased VA-ES-BJ xenograft tumor growth. Taken together, our findings revealed that INI1 loss in EpS cells enhances the expression of AURKA and its downstream effectors and persistently activates PLK1 and CDC25C mediated by AURKA, making the cells reliant on the AURKA/PLK1/CDC25C axis. Therefore, the AURKA/PLK1/CDC25C axis activated by INI1 deficiency could serve as a novel therapeutic target for this devastating disease.

SEPT5 overexpression predicts poor prognosis and promotes progression through feedback regulation of HIF-1α in clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC), a predominant subtype of renal cell carcinoma, significantly contributes to the heightened morbidity and mortality in individuals diagnosed with urologic tumors. The challenges posed by high malignancy at the initial diagnosis of ccRCC, therapeutic resistance, and unfavorable patient prognosis remain largely unresolved. Our findings indicate that SEPT5 is upregulated in ccRCC and this upregulation is associated with an adverse prognosis for ccRCC patients. Furthermore, we demonstrate that overexpression of SEPT5 promotes proliferation of ccRCC cells, alters their cell cycle distribution, and enhances their migratory and invasive capabilities. Additionally, we observe a positive correlation between SEPT5 overexpression and resistance to sorafenib and sunitinib in ccRCC cells. Further mechanistic investigations have revealed that SEPT5 serves as a novel direct transcriptional target of HIF-1α, leading to subsequent reduction in protein expression and nuclear translocation of HIF-1α. This establishes a feedback loop in ccRCC tumorigenesis. Ultimately, knockdown of SEPT5 significantly inhibits xenografted tumor growth in vivo. Overall, this study provides compelling evidence that directly targeting the HIF-1α-SEPT5 feedback axis may be an effective approach for suppressing the proliferation and progression of ccRCC, offering new insights into the diagnosis and treatment of ccRCC patients.

Structure-Guided Discovery of Novel N4-(Substituted Thiazol-2-yl)-N2-(4-Substituted phenyl)pyrimidine-2,4-Diamines as Potent CDK2 and CDK9 Dual Inhibitors with High Oral Bioavailability.

CDK2 and CDK9 play pivotal roles in cell cycle progression and gene transcription, respectively, making them promising targets for cancer treatment. Herein, we discovered a series of N4-(substituted thiazol-2-yl)-N2-(4-substituted phenyl)pyrimidine-2,4-diamines as highly potent CDK2/9 dual inhibitors. Especially, compound 20a significantly inhibited CDK2 (IC50 = 0.004 μM) and CDK9 (IC50 = 0.009 μM), achieving a 1000- and 2800-fold improvement over lead compound 11, and demonstrating broad antitumor efficacy. Mechanistic studies indicated that 20a effectively and simultaneously suppressed CDK2 and CDK9 proteins in the HCT116 cell line, leading to G2/M cell cycle arrest and cell apoptosis by regulating cell cycle- and apoptosis-related protein expression. Most importantly, 20a exhibited 86.7% oral bioavailability in rats and effectively inhibited tumor growth in HCT116 xenograft and C6 glioma rat models without significant toxicity. Overall, these observations clearly confirmed the promising therapeutic strategy of CDK2/9 dual inhibitors and provided a novel potent candidate for cancer therapy.

RPL36A activates ERK pathway and promotes colorectal cancer growth.

Ribosomal protein L36A (RPL36A) was one of the most upregulated proteins in colorectal cancer (CRC), yet its role in colorectal cancer (CRC) remains largely unexplored, with limited studies investigating its expression and biological functions. In this investigation, we confirmed a marked upregulation of RPL36A in CRC tissues, correlating with an adverse prognosis. Silencing RPL36A markedly attenuated CRC cell malignant properties and tumor xenograft growth. Further mechanistic analysis indicated that RPL36A depletion diminished phosphorylated ERK levels, subsequently impacting the expression of c-Myc and ELK1, key downstream effectors in the MAPK/ERK pathway. Notably, the tumor-suppressive effects of RPL36A knockdown could be negated by an ERK activator. Collectively, our findings underscore the oncogenic function of RPL36A in CRC and propose it as a potential target for therapeutic intervention.

Centipeda minima extracts and the active sesquiterpene lactones have therapeutic efficacy in non-small cell lung cancer by suppressing Skp2/p27 signaling pathway.

Centipeda minima (L.) A. Braun & Asch (C. minima) was applied to treat nasal allergy, headache, cough, and even nasopharyngeal carcinoma in traditional Chinese medicine. However, the underlying anticancer mechanisms of C. minima and its active components have not been systematically illustrated. The study aims to examine the therapeutic efficacy of the ethanol extract of C. minima (ECM) and its active components in non-small cell lung cancer (NSCLC) and illustrate the underlying mechanisms. The main chemical components in the ethanol extract of C. minima (ECM) and the supercritical CO2 fluid extract of C. minima (CM-SFE) were determined by using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The antitumor effects of ECM and CM-SFE were examined by using NSCLC cell xenografts. The flow cytometry, cell colony formation, wound-healing, transwell assay, and Western blotting were conducted to investigate the anticancer properties of ECM, CM-SFE, and these sesquiterpene lactones that abundantly distributed in these extracts. We first determined that ECM contains high levels of sesquiterpene lactones. ECM can markedly induce cell cycle arrest and suppress migration and invasion of NSCLC cells. Mechanistically, ECM promoted proteasome-dependent degradation of Skp2 protein and induced the accumulation of its substrates p27; whereas Skp2 overexpression can attenuate the inhibitory effects of ECM on NSCLC proliferation and migration. Moreover, ECM at 200-600mg/kg can significantly inhibit tumor growth and metastasis in A549-luciferase cell orthotopic xenografts by suppressing Skp2 expression. The sesquiterpene lactones that abundantly distributed in ECM, including 6-O-angeloylplenolin (6-OAP), arnicolide D (ArD) and arnicolide C (ArC), were also demonstrated to decrease Skp2 while increase p27 protein level, thereby significantly inducing cell cycle arrest and suppressing migration of NSCLC cells. Notably, CM-SFE, which mainly consisted of 6-OAP, ArD and ArC, exhibited much stronger anti-NSCLC activity than that of ECM in A549-luciferase cell orthotopic xenografts. Our results demonstrate that the active components in C. minima possesses potential anti-NSCLC activities by suppressing Skp2/p27 signaling pathway, and these active sesquiterpene lactones can be further developed as potent Skp2 inhibitor to treat NSCLC.

Coccinic acid exhibits anti-tumor efficacy against NSCLC harboring EGFR L858R/T790M mutation via the EGFR/STAT3 pathway.

Epidermal growth factor receptor (EGFR) is a starring target for the treatment of non-small cell lung cancer (NSCLC). EGFR tyrosine kinase inhibitors (EGFR-TKIs) have been used to treat NSCLC patients with EGFR-activating mutations. However, most patients invariably develop resistance to these agents due to the occurrence of novel mutations at the EGFR kinase domain. There is an urgent need to develop more effective therapy strategies to provide more selection for patients with NSCLC. Coccinic acid was reported to exerts potential anti-tumor effects, but its mechanism has not been elucidated and warrants investigation. In this study, coccinic acid was shown to inhibit cell proliferation on cells harboring L858R/T790M mutant EGFR by suppressing p-EGFR and p-STAT3. It was also shown that coccinic acid promoted cell cycle distribution and showed a potent apoptosis-inducing efficacy. Further results in vivo assays demonstrated that coccinic acid reduced tumor growth of NCI-H1975 xenograft in nude mice via the EGFR/STAT3 signaling. Moreover, these effects are involving in the binding of coccinic acid to the EGFR extracellular domain. In conclusion, our finding demonstrated that coccinic acid may be utilized as a potential novel candidate for NSCLC with EGFR L858R/T790M mutation.

EGR1 inhibits clear cell renal cell carcinoma proliferation and metastasis via the MAPK15 pathway.

Clear cell renal carcinoma (ccRCC), the leading histological subtype of RCC, lacks any targeted therapy options. Although some studies have shown that early growth response factor 1 (EGR1) has a significant role in cancer development and progression, its role and underlying mechanisms in ccRCC remain poorly understood. The Cancer Genome Atlas (TCGA) database was utilized to examine the expression of EGR1 in ccRCC. The expression of EGR1 in 55 ccRCC tissues was evaluated using immunohistochemistry. The link between EGR1 expression and clinicopathological variables was examined through an analysis. Gain-of-function assays were employed to investigate EGR1's biological functions in ccRCC cells, involving proliferation, colony formation, invasion assays, and tumorigenesis in nude mice. In order to assess the protein expression of mitogen-activated protein kinase 15 (MAPK15), E-cadherin, matrix metalloproteinase-9/-2 (MMP-9 and MMP-2), Western blot technique was applied. The results revealed a decrease in EGR1 expression in ccRCC tissues. This decrease was strongly linked to TNM stage, lymphatic metastasis, tumor size, histological grade, and unfavorable prognosis in ccRCC patients. It has been demonstrated that overexpressing EGR1 inhibits the growth of xenograft tumors in vivo and inhibits cell colony formation, motility, and invasion in vitro. Furthermore, EGR1 can prevent the development and movement of ccRCC cells by controlling the expression of MMP-2, MMP-9, E-cadherin, and MAPK15. The EGR1/MAPK15 axis may represent a promising target for drug development, with EGR1 serving as a possible target for ccRCC therapy.

Spectrum and carcinogenic properties of thyroglobulin gene fusions in thyroid.

Approximately 10-20% of thyroid cancers are driven by gene fusions, which activate oncogenic signaling through aberrant overexpression, ligand-independent dimerization, or loss of inhibitory motifs. We identified 13 thyroid tumors with thyroglobulin (TG) gene fusions and aimed to assess their histopathology and the fusions' oncogenic and tumorigenic properties. Of 11 cases with surgical pathology, 82% were carcinomas and 18% noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP). TG fusions preserved exon(s) 1, 1-15, 1-35 or, most frequently, 1-47 of TG and, based on the 3' partner were grouped as (i) involving receptor tyrosine kinases (RTKs) (TG::FGFR1, TG::RET, TG::ALK, TG::NTRK1), (ii) driving aberrant DPRX and chromosome 19 microRNA cluster expression (TG::DPRX), or (iii) involving IGF2 mRNA-binding protein (TG::IGF2BP1). All 13 fusion-positive tumors exhibited strong (8.5±3.3 log2-fold) 3' partner overexpression driven by the TG promoter. Gene expression analysis revealed TG::RET- and TG::ALK-positive tumors being BRAFV600E-like and remaining tumors RAS-like. In thyroid PCCL3 cells, the TG::NTRK1 fusion demonstrated both spontaneous and ligand-associated dimerization, activated downstream MAPK, AKT, and STAT3 signaling, and drove xenograft tumorigenesis in nude mice. FDA-approved NTRK inhibitors entrectinib and larotrectinib effectively blocked TG::NTRK1 signaling in vitro and inhibited xenograft tumor growth in vivo. In summary, we report a spectrum of TG gene fusions as recurrent oncogenic events in thyroid cancer and NIFTP that drive strong overexpression of partner genes, frequently RTKs. The TG::NTRK1 fusion is prone to dimerization, activates oncogenic signaling, drives tumorigenesis in thyroid cells, and, like other fusions involving RTKs, represents a potential therapeutic target in thyroid cancer.

Thiostrepton suppresses colorectal cancer progression through reactive oxygen species related endoplasmic reticulum stress.

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Due to the poor therapeutic efficacy of CRC treatments and poor prognosis of the disease, effective treatment strategies are urgently needed. As long-term proteotoxic stress is a major cause of cell death, agents that induce proteotoxic stress offer a promising strategy for cancer intervention. Thiostrepton is a natural antibiotic derived from the Streptomyces genus. In the present study, we found that thiostrepton triggered apoptosis, reduced the migration of CRC cells, and inhibited xenograft tumour growth in vivo. Mechanistically, thiostrepton reduced proteasome activity; induced the aggregation of ubiquitinated proteins; caused endoplasmic reticulum (ER) stress, which was characterized by increased protein levels of GRP78, ATF4, P-eIF2α, and CHOP and cytosolic calcium release; and ultimately resulted in cell death. Thiostrepton-related changes in cell survival and cell migration, as well as mechanistical processes, were almost completely reversed by treatment with the antioxidant N-acetylcysteine (NAC), suggesting that the mechanism is dependent on reactive oxygen species (ROS). These results demonstrated that thiostrepton induced apoptosis and inhibited migration through ROS-induced ER stress and proteotoxic stress in colorectal cancer.

CDH3-AS1 antisense RNA enhances P-cadherin translation and acts as a tumor suppressor in melanoma.

Thousands of regulatory noncoding RNAs (ncRNAs) have been annotated; however, their functions in gene regulation and contributions to cancer formation remain poorly understood. To gain a better understanding of the influence of ncRNAs on gene regulation during melanoma progression, we mapped the landscape of ncRNAs in melanocytes and melanoma cells. Nearly half of deregulated genes in melanoma are ncRNAs, with antisense RNAs (asRNAs) comprising a large portion of deregulated ncRNAs. CDH3-AS1, the most significantly downregulated asRNA, overlaps the CDH3 gene, which encodes P-cadherin, a transmembrane glycoprotein involved in cell adhesion that was also reduced in melanoma. Overexpression of CDH3-AS1 increased cell aggregation and reduced xenograft tumor growth, mimicking the tumor-suppressive effects of CDH3. CDH3-AS1 interacted with CDH3 mRNA and enhanced P-cadherin protein levels. Interestingly, secondary structures at the CDH3 5' end regulated P-cadherin translation, and ribosome profiling revealed that CDH3-AS1 promotes ribosome occupancy at the CDH3 mRNA. Notably, ribosome occupancy was generally increased in mRNAs having cognate asRNA that are complementary to the 5'UTR. Taken together, this study revealed the CDH3-AS1-mediated enhancement of P-cadherin translation, underscoring the broader potential of asRNAs as regulators of protein-coding genes and their role in diseases like melanoma.