Tumors In Nude Mice Research Articles

Antipsychotic Zuclopenthixol Inhibits Melanoma Growth and Brain Metastasis by Inducing Apoptosis and Cell Cycle Arrest.

The incidence of melanoma brain metastasis (MBM) is high and significantly compromises patient survival and quality of life. Effective treatment of MBM is made difficult by the blood-brain barrier (BBB), since it restricts the entry of drugs into the brain. Certain anti-psychotic drugs able to cross the BBB have demonstrated efficacy in suppressing brain metastasis in preclinical studies. However, the activity of zuclopenthixol against MBM is not yet clear. Cell viability assays were employed to investigate the potential of zuclopenthixol in the treatment of MBM. Subsequently, the mechanism of action was investigated by RNA-sequencing (RNAseq), flow cytometry-based cell cycle and apoptosis assays, protein expression analysis, and autophagy flux detection. Additionally, the efficacy of zuclopenthixol against tumor growth was investigated in vivo, including MBM models. Zuclopenthixol inhibited the proliferation of various melanoma cell lines at minimal doses by causing cell cycle arrest in the G0/G1 phase and mitochondrial-mediated intrinsic apoptosis. Zuclopenthixol also induced cytoprotective autophagy, and inhibition of autophagy enhanced the anti-melanoma effects of zuclopenthixol. Furthermore, zuclopenthixol inhibited the growth of human melanoma tumors in nude mice, as well as the growth of intracranial metastases in a mouse model of MBM. These results demonstrate that zuclopenthixol has significant potential as an effective therapeutic agent for MBM.

METTL3 orchestrates glycolysis by stabilizing the c-Myc/WDR5 complex in triple-negative breast cancer

BackgroundThe carcinogenic transcription factor c-Myc is the most aggressive oncogene, which drive malignant transformation and dissemination of triple-negative breast cancer (TNBC). Recruitment of many cofactors, especially WDR5, a protein that nucleates H3K4me chromatin modifying complexes, play a pivotal role in regulating c-Myc-dependent gene transcription, a critical process for c-Myc signaling to function in a variety of biological and pathological contexts. For this reason, interrupting the interaction between c-Myc and the transcription cofactor WDR5 may become the most promising new strategy for treating c-Myc driven TNBC. MethodsImmunoprecipitation and mass spectrometry (IP-MS) is used to screen proteins that bind c-Myc/WDR5 interactions. The interaction of METTL3 with c-Myc/WDR5 in breast cancer tissues and TNBC cells was detected by Co-IP and immunofluorescence. Subsequently, we further analyzed the influence of METTL3 expression on c-Myc/WDR5 protein expression and its interaction stability by Western blot and Co-IP. The correlation between METTL3 and c-Myc pathway was analyzed by ChIP-seq sequencing and METTL3 knockdown transcriptome data. The effect of METTL3 expression on c-Myc transcriptional activity was detected by ChIP-qPCR and Dual Luciferase Reporter. At the same time, the overexpression vector METTL3-MUT (m6A) was constructed, which mutated the methyltransferase active site (Aa395–398, DPPW/APPA), and further explored whether the interaction between METTL3 and c-Myc/WDR5 was independent of methyltransferase activity. In addition, we also detected the changes of METTL3 expression on TNBC's sensitivity to small molecule inhibitors such as JQ1 and OICR9429 by CCK8, Transwell and clonal formation assays. Finally, we further verified our conclusions in spontaneous tumor formation mouse MMTV-PyMT and nude mouse orthotopic transplantation tumor models. ResultsMETTL3 was found to bind mainly to c-Myc/WDR5 protein in the nucleus. It enhances the stability of c-Myc/WDR5 interaction through its methyltransferase independent mechanism, thereby enhancing the transcriptional activity of c-Myc on downstream glucose metabolism genes. Notably, the study also confirmed that METTL3 can directly participate in the transcription of glucose metabolism genes as a transcription factor, and knockdown METTL3 enhances the drug sensitivity of breast cancer cells to small molecule inhibitors JQ1 and OICR9429. The study was further confirmed by spontaneous tumor formation mouse MMTV-PyMT and nude mouse orthotopic transplantation tumor models. ConclusionMETTL3 binds to the c-Myc/WDR5 protein complex and promotes glycolysis, which plays a powerful role in promoting TNBC progression. Our findings further broaden our understanding of the role and mechanism of action of METTL3, and may open up new therapeutic avenues for effective treatment of TNBC with high c-Myc expression.

Abstract 1840: MYBBP1A AMPylated by SELO to influence its function

Abstract Introduction: MYBBP1A, named Myb-binding protein 1A, is a protein that mainly locates in nucleolar and shuttles between the nucleus and cytoplasm, nuclear import may be mediated by KPNA2, however export depend partially on XPO1/CRM1. It activates or represses transcription via interactions with sequence specific DNA-binding proteins. Repression may be mediated at least in part by histone deacetylase activity (HDAC activity). Acts as a corepressor and in concert with CRY1, represses the transcription of the core circadian clock component PER2. Preferentially binds to di-methylated histone H3 'Lys-9' (H3K9me2) on the PER2 promoter. MYBBP1A overexpressed in tumor than normal and have a significantly negative correlation with patient overall survival. We aim to explore the role of MYBBP1A in PDAC progression and underlying mechanism. In our research, we find and prove the novel AMPylating enzyme SELO-AMPylate MYBBP1A inhibits PDAC progression and modified site in S1353 and further influence downstream relative RNA, such as 18s rRNA, 28S rRNA. Methods and Materials: 1. The function of MYBBP1A in tumorigenesis at the organismal and cellular levels. MYBBP1A is widely expressed in different tissues. Firstly, we explored the correlation between MYBBP1A expression level and PDAC through TCGA database and Kaplan-Meier plotter. We then established MYBBP1A gene knockout mice mating with PDX/P53K172H/KRASG12C to induced a primary PDAC model to analyze the progression of pancreatic cancer. The effect of MYBBP1A on tumor cell growth and proliferation was explored through cell proliferation analysis and a nude mouse tumor xenograft model. 2. The MYBBP1A AMPylated by SELO influence MYBBP1A function in cell proliferation was investigated at the molecular and cellular levels. AMPylation-specific antibodies were used to confirmed MYBBP1A AMPylated by SELO in both cell lysates and purified proteins through experiments such as CO-IP and WB. Stably expressed MYBBP1A WT/S1353A were constructed to verify the function in cell proliferation or migration by SELO. The signaling molecules were further explored through CO-IP and WB to identify the changed molecular by SELO-AMPylate-MYBBP1A, revealing the entire signaling pathways of AMPylation-mediated regulation of PDAC proliferation. Conclusion: We have demonstrated the function of MYBBP1A in the formation of pancreatic cancer, and further revealed SELO-AMPylate-MYBBP1A importance in the process of reversing MYBBP1A’s role, which has played a certain significance for the treatment of pancreatic cancer and the exploration of related therapeutic targets. Citation Format: Wu Li. MYBBP1A AMPylated by SELO to influence its function [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1840.

RBM24 Suppresses the Tumorigenesis of Glioblastoma by Stabilizing LATS1 mRNA.

The ribose nucleic acid (RNA)-binding motif protein 24 (RBM24) has been recognized as a critical regulatory protein in various types of tumors. However, its specific role in glioblastoma (GBM) has not been thoroughly investigated. The objective of this study is to uncover the role of RBM24 in GBM and understand the underlying mechanism. The expression of RBM24 in GBM was initially analyzed using the Gene Expression Profiling Interactive Analysis (GEPIA). Subsequently, the RBM24 expression levels in clinical samples of GBM were examined, and the survival curves of GBM patients were plotted based on high- and low-expression levels of RBM24 using Kaplan-Meier (KM) plotter. In addition, RBM24 knockdown cell lines and overexpression vectors were created to assess the effects on proliferation, apoptosis, and invasion abilities. Finally, the binding level of RBM24 protein to LATS1 messenger RNA (mRNA) was determined by RNA immunoprecipitation (RIP) assay, and the expression levels of RBM24 and LATS1 were measured through quantitative reverse-transcriptase-polymerase chain reaction (qRT-PCR) and Western blot (WB). Our data revealed a significant decrease in RBM24 mRNA and protein levels in GBM patients, indicating that those with low RBM24 expression had a worse prognosis. Overexpression of RBM24 led to inhibited cell proliferation, reduced invasion, and increased apoptosis in LN229 and U87 cells. In addition, knocking down LATS1 partially reversed the effects of RBM24 on cell proliferation, invasion, and apoptosis in GBM cells. In vivo xenograft model further demonstrated that RBM24 overexpression reduced the growth of subcutaneous tumors in nude mice, accompanied by a decrease in Ki-67 expression and an increase in apoptotic events in tumor tissues. There was also correlation between RBM24 and LATS1 protein expression in the xenograft tumors. RBM24 functions to stabilize LATS1 mRNA, thereby inhibiting the proliferation, suppressing invasion, and promoting apoptosis in GBM cells.

Single-cell transcriptomic sequencing data reveal aberrant DNA methylation in SMAD3 promoter region in tumor-associated fibroblasts affecting molecular mechanism of radiosensitivity in non-small cell lung cancer

ObjectiveNon-small cell lung cancer (NSCLC) often exhibits resistance to radiotherapy, posing significant treatment challenges. This study investigates the role of SMAD3 in NSCLC, focusing on its potential in influencing radiosensitivity via the ITGA6/PI3K/Akt pathway.MethodsThe study utilized gene expression data from the GEO database to identify differentially expressed genes related to radiotherapy resistance in NSCLC. Using the GSE37745 dataset, prognostic genes were identified through Cox regression and survival analysis. Functional roles of target genes were explored using Gene Set Enrichment Analysis (GSEA) and co-expression analyses. Gene promoter methylation levels were assessed using databases like UALCAN, DNMIVD, and UCSC Xena, while the TISCH database provided insights into the correlation between target genes and CAFs. Experiments included RT-qPCR, Western blot, and immunohistochemistry on NSCLC patient samples, in vitro studies on isolated CAFs cells, and in vivo nude mouse tumor models.ResultsFifteen key genes associated with radiotherapy resistance in NSCLC cells were identified. SMAD3 was recognized as an independent prognostic factor for NSCLC, linked to poor patient outcomes. High expression of SMAD3 was correlated with low DNA methylation in its promoter region and was enriched in CAFs. In vitro and in vivo experiments confirmed that SMAD3 promotes radiotherapy resistance by activating the ITGA6/PI3K/Akt signaling pathway.ConclusionHigh expression of SMAD3 in NSCLC tissues, cells, and CAFs is closely associated with poor prognosis and increased radiotherapy resistance. SMAD3 is likely to enhance radiotherapy resistance in NSCLC cells by activating the ITGA6/PI3K/Akt signaling pathway.

Easy but Efficient: Facile Approach to Molecule with Theoretically Justified Donor-Acceptor Structure for Effective Photothermal Conversion and Intravenous Photothermal Therapy.

To accelerate the pace in the field of photothermal therapy (PTT), it is urged to develop easily accessible photothermal agents (PTAs) showing high photothermal conversion efficiency (PCE). As a proof-of-concept, hereby a conventional strategy is presented to prepare donor-acceptor (D-A) structured PTAs through cycloaddition-retroelectrocyclization (CA-RE) reaction, and the resultant PTAs give high PCE upon near-infrared (NIR) irradiation. By joint experimental-theoretical study, these PTAs exhibit prominent D-A structure with strong intramolecular charge transfer (ICT) characteristics and significantly twisting between D and A units which account for the high PCEs. Among them, the DMA-TCNQ exhibits the strongest absorption in NIR range as well as the highest PCE of 91.3% upon irradiation by 760-nm LED lamp (1.2W cm-2). In vitro and in vivo experimental results revealed that DMA-TCNQ exhibits low dark toxicity and high phototoxicity after IR irradiation along with nude mice tumor inhibition up to 81.0% through intravenous therapy. The findings demonstrate CA-RE reaction as a convenient approach to obtain twisted D-A structured PTAs for effective PTT and probably promote the progress of cancer therapies.

SAA1 regulated by S1P/S1PR1 promotes the progression of ESCC via β-catenin activation

Serum amyloid A1 (SAA1), an inflammation-related molecule, is associated with the malignant progression of many tumors. This study aimed to investigate the role of SAA1 in the progression of esophageal squamous cell carcinoma (ESCC) and its molecular mechanisms. The expression of SAA1 in ESCC tissues and cell lines was analyzed using bioinformatics analysis, western blotting, and reverse transcription-quantitative PCR (RT‒qPCR). SAA1-overexpressing or SAA1-knockdown ESCC cells were used to assess the effects of SAA1 on the proliferation, migration, apoptosis of cancer cells and the growth of xenograft tumors in nude mice. Western blotting, immunofluorescence and RT‒qPCR were used to investigate the relationship between SAA1 and β-catenin and SAA1 and sphingosine 1-phosphate (S1P)/sphingosine 1-phosphate receptor 1 (S1PR1). SAA1 was highly expressed in ESCC tissues and cell lines. Overexpression of SAA1 significantly promoted the proliferation, migration and the growth of tumors in nude mice. Knockdown of SAA1 had the opposite effects and promoted the apoptosis of ESCC cells. Moreover, SAA1 overexpression promoted the phosphorylation of β-catenin at Ser675 and increased the expression levels of the β-catenin target genes MYC and MMP9. Knockdown of SAA1 had the opposite effects. S1P/S1PR1 upregulated SAA1 expression and β-catenin phosphorylation at Ser675 in ESCC cells. In conclusion, SAA1 promotes the progression of ESCC by increasing β-catenin phosphorylation at Ser675, and the S1P/S1PR1 pathway plays an important role in its upstream regulation.

DOCK1 regulates the malignant biological behavior of endometrial cancer through c-Raf/ERK pathway

BackgroundThe effect of DOCK1 gene on the biological behavior of endometrial carcinoma cells and its related pathway has not been reported.MethodsThe immunohistochemical method and western blot were utilized to analyze DOCK1 protein expression in endometrial tissues and cells, respectively. CCK-8, BrdU, transwell and flow cytometry were performed to analyze the effect of DOCK1 expression changes on the viability, proliferation, invasion, migration and apoptosis of endometrial cancer cells, respectively. The effects of DOCK1 gene on Bcl-2, MMP9, Ezrin, E-cadherin and c-RAF/ERK1/2 signaling pathway were evaluated by western blot. The xenograft models were constructed to analyze the effect of DOCK1 in vivo.ResultsDOCK1 expression was increased in endometrial cancer tissues and cells compared with those in normal adjacent tissues and cells. DOCK1 knockout could inhibit the malignant biological behavior of endometrial cancer cells, while DOCK1 overexpression played the opposite effect. The expression of E-cadherin was upregulated and those of MMP9, Ezrin, Bcl-2, p-c-RAF (S338) and p-ERK1/2 (T202/Y204) were downregulated after DOCK1 knockout, while DOCK1 overexpression played the opposite effect. Additionally, Raf inhibitor LY3009120 reversed the function of DOCK1 on malignant biological behavior. In vivo experiment results showed that the growth and weight of transplanted tumors in nude mice were inhibited after DOCK1 knockout. The changes of E-cadherin, MMP9, Ezrin and Bcl-2 expressions in the transplanted tumors were consistent with those in vitro.ConclusionDOCK1 could enhance the malignant biological behavior of endometrial cancer cells, which might be through c-RAF/ERK1/2 signaling pathways in vitro and in vivo.

TRMT13 inhibits the growth of papillary thyroid cancer by targeting ANAPC4.

The recently discovered gene TRMT13 encodes a type of RNA methylase and is a member of the CCDC family (also called CCDC76). Here, we delineate its role in papillary thyroid cancer (PTC). Bioinformatics analysis shows significant TRMT13 and ANAPC4 downregulation in PTC and reveals that the expression levels of both genes are linearly correlated. Subsequent analyses confirm that both TRMT13 and ANAPC4 expressions are downregulated in PTC tissues and that this change in expression has a significant impact on cancer diagnosis. We conduct assays on PTC cells subjected to TRMT13 and ANAPC4 silencing or overexpression to assess the biological effects of these genes. We also perform rescue experiments to validate the regulatory effects of TRMT13 on ANAPC4. A nude mouse tumor model is used to evaluate the effects of TRMT13 and ANAPC4 on PTC tumorigenesis. TRMT13 expression is decreased in PTC tissues and cell lines and is positively correlated with that of ANAPC4. Cell assays reveal that TRMT13/ANAPC4 attenuates the malignancy of PTC cells by restraining cell proliferation, migration and invasion, while rescue experiments corroborate that ANAPC4 is a downstream target of TRMT13. In the nude mouse xenograft model, both TRMT13 and ANAPC4 inhibit tumor growth, and TRMT13 and ANAPC4 expression levels are significantly associated with survival. Taken together, these findings lead to the conclusion that TRMT13 inhibits PTC growth via ANAPC4, indicating a new role of TRMT13 and providing insights into the tRNA methyltransferase and coiled-coil domain-containing protein families.

METTL3 inhibitor STM2457 impairs tumor progression and enhances sensitivity to anlotinib in OSCC.

To investigate the inhibitory effects of STM2457, which is a novel METTL3 (m6A writer) inhibitor, both as a monotherapy and in combination with anlotinib, in the treatment of oral squamous cell carcinoma (OSCC) both invitro and invivo. The efficacy of STM2457 or STM2457 plus anlotinib was evaluated using two OSCC cell lines by CCK8, transwell, colony formation, would-healing, sphere formation, cell cycle, apoptosis assays, and nude mice tumor xenograft techniques. The molecular mechanism study was carried out by western blotting, qRT-PCR, MeRIP-qPCR, immunofluorescence, and immunohistochemistry. STM2457 combined with anlotinib enhanced inhibition of cellular survival/proliferation and promotion of apoptosis invitro. Moreover, this combinatorial approach exerted a notable reduction in stemness properties and EMT (epithelial-mesenchymal transition) features of OSCC cells. Remarkably, invivo studies validated the efficacy of the combination treatment. Mechanistically, our investigations revealed that the combined action of STM2457 and anlotinib exerted downregulatory effects on EGFR (epidermal growth factor receptor) expression in OSCC cells. The combination of STM2457 and anlotinib targeting EGFR exerted a multiple anti-tumor effect. In near future, anlotinib combined with STM2457 may provide a novel insight for the treatment of OSCC.

ELK1/MTOR/S6K1 Pathway Contributes to Acquired Resistance to Gefitinib in Non-Small Cell Lung Cancer.

The development of acquired resistance to small molecule tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) signaling has hindered their efficacy in treating non-small cell lung cancer (NSCLC) patients. Our previous study showed that constitutive activation of the 70 kDa ribosomal protein S6 kinase 1 (S6K1) contributes to the acquired resistance to EGFR-TKIs in NSCLC cell lines and xenograft tumors in nude mice. However, the regulatory mechanisms underlying S6K1 constitutive activation in TKI-resistant cancer cells have not yet been explored. In this study, we recapitulated this finding by taking advantage of a gefitinib-resistant patient-derived xenograft (PDX) model established through a number of passages in mice treated with increasing doses of gefitinib. The dissociated primary cells from the resistant PDX tumors (PDX-R) displayed higher levels of phosphor-S6K1 expression and were resistant to gefitinib compared to cells from passage-matched parental PDX tumors (PDX-P). Both genetic and pharmacological inhibition of S6K1 increased sensitivity to gefitinib in PDX-R cells. In addition, both total and phosphorylated mechanistic target of rapamycin kinase (MTOR) levels were upregulated in PDX-R and gefitinib-resistant PC9G cells. Knockdown of MTOR by siRNA decreased the expression levels of total and phosphor-S6K1 and increased sensitivity to gefitinib in PDX-R and PC9G cells. Moreover, a transcription factor ELK1, which has multiple predicted binding sites on the MTOR promoter, was also upregulated in PDX-R and PC9G cells, while the knockdown of ELK1 led to decreased expression of MTOR and S6K1. The chromatin immunoprecipitation (ChIP)-PCR assay showed the direct binding between ELK1 and the MTOR promoter, and the luciferase reporter assay further indicated that ELK1 could upregulate MTOR expression through tuning up its transcription. Silencing ELK1 via siRNA transfection improved the efficacy of gefitinib in PDX-R and PC9G cells. These results support the notion that activation of ELK1/MTOR/S6K1 signaling contributes to acquired resistance to gefitinib in NSCLC. The findings in this study shed new light on the mechanism for acquired EGFR-TKI resistance and provide potential novel strategies by targeting the ELK1/MTOR/S6K1 pathway.

Repression of YEATS2 induces cellular senescence in hepatocellular carcinoma and inhibits tumor growth

ABSTRACT Hepatocellular carcinoma (HCC) stands as the third leading cause of cancer-related fatalities globally. In this study, we observed a significant increase in the expression level of the YEATS2 gene in HCC patients, and it is negatively correlated with the patients’ survival rate. While we have previously identified the association between YEATS2 and the survival of pancreatic cancer cells, the regulatory mechanisms and significance in HCC are still to be fully elucidated. Our study shows that knockdown (KD) of YEATS2 expression leads to DNA damage, which in turn results in an upregulation of γ-H2A.X expression and activation of the canonical senescence-related pathway p53/p21Cip1. Moreover, our transcriptomic analysis reveals that YEATS2 KD cells can enhance the expression of p21Cip1 via the c-Myc/miR-93-5p pathway, consequently fostering the senescence of HCC cells. The initiation of cellular senescence through dual-channel activation suggests that YEATS2 plays a pivotal regulatory role in the process of cell proliferation. Ultimately, our in vivo research utilizing a nude mouse tumor model revealed a notable decrease in both tumor volume and weight after the suppression of YEATS2 expression. This phenomenon is likely attributable to the attenuation of proliferative cell activity, coupled with a concurrent augmentation in the population of natural killer (NK) cells. In summary, our research results have supplemented the understanding of the regulatory mechanisms of HCC cell proliferation and indicated that targeting YEATS2 may potentially inhibit liver tumor growth.

Modulating pancreatic cancer microenvironment: The efficacy of Huachansu in mouse models via TGF-β/Smad pathway

Ethnopharmacological relevanceHuachansu (HCS) is a traditional Chinese medicine obtained from the dried skin glands of Bufo gargarizans and clinical uses of HCS have been approved in China to treat malignant tumors. The traditional Chinese medicine theory states that HCS relieves patients with cancer by promoting blood circulation to remove blood stasis. Clinical observation found that local injection of HCS given to pancreatic cancer patients can significantly inhibit tumor progression and assist in enhancing the efficacy of chemotherapy. However, the material basis and underlying mechanism have not yet been elucidated. Aim of the studyTo investigate the therapeutic potential of HCS for the treatment of pancreatic cancer in in situ transplanted tumor nude mouse model. Furthermore, this study sought to elucidate the molecular mechanisms underlying its efficacy and assess the impact of HCS on the microenvironment of pancreatic cancer. To identify the antitumor effect of HCS in in situ transplanted tumor nude mouse model and determine the Chemopreventive mechanism of HCS on tumor microenvironment (TME). MethodsUsing the orthotopic transplantation nude mouse model with fluorescently labeled pancreatic cancer cell lines SW1990 and pancreatic stellate cells (PSCs), we examined the effect of HCS on the pancreatic ductal adenocarcinoma (PDAC) microenvironment based on the transforming growth factor β (TGF-β)/Smad pathway. The expression of TGF-β, smad2, smad3, smad4, collagen type-1 genes and proteins in nude mouse model were detected by qRT-PCR and Western blot. ResultsHCS significantly reduced tumor growth rate, increased the survival rate, and ameliorated the histopathological changes in the pancreas. It was found that HCS concentration-dependently reduced the expression of TGF-β1 and collagen type-1 genes and proteins, decreased the expression of Smad2 and Smad3 genes, and downregulated the phosphorylation level of Smad2/3. Additionally, the gene and protein expression of Smad4 were promoted by HCS. Further, the promoting effect gradually enhanced with the rise of HCS concentration. ConclusionsThe results demonstrated HCS could regulate the activity of the TGF-β/Smad pathway in PDAC, improved the microenvironment of PDAC and delayed tumor progression. This study not only indicated that the protective mechanism of HCS on PDAC might be attributed partly to the inhibition of cytokine production and the TGF-β/Smad pathway, but also provided evidence for HCS as a potential medicine for PDAC treatment.

Epigenetic upregulation of MNAT1 by SMYD2 is linked to PI3K/AKT activation and tumorigenesis of pancreatic adenocarcinoma.

Dysregulation of histone methyltransferase SET and MYND domain-containing protein 2 (SMYD2) has been correlated with human developmental disorders and cancers. This research aims to investigate the roles of SMYD2 and its interacted molecules in pancreatic adenocarcinoma (PAAD). Two PAAD-related gene expression datasets were downloaded to screen key molecules involved in tumor progression. SMYD2 was expressed at high levels in PAAD tissues and cells. SMYD2 silencing suppressed while its overexpression promoted proliferation, invasiveness, migration, apoptosis resistance, and cell cycle progression of PAAD cells. Target molecules of SMYD2 were predicted by online tools and validated by chromatin immunoprecipitation and luciferase assays. SMYD2 catalyzed H3K36me2 modification at the promoter region of MNAT1 component of CDK activating kinase (MNAT1), to promote its transcription. MNAT1 was correlated with an unfavorable clinical outcome of PAAD patients. Alteration of MNAT1 alone also affected the malignant behavior of PAAD cells. Moreover, MNAT1 overexpression in cells rescued the malignant phenotype of cells suppressed by SMYD2 silencing. MNAT1 activated the phosphatidyl inositol 3-kinase/protein kinase B (PI3K/AKT) signaling. In vivo, SMYD2 silencing decreased the growth rate and weight of xenograft tumors in nude mice. Overall, this paper demonstrates that SMYD2-mediated MNAT1 upregulation is linked to PAAD tumorigenesis via PI3K/AKT pathway activation.

Effect of Staphylococcal Nuclease and Tudor Domain Containing 1/SLC7A11 on the Occurrence and Development of Osteosarcoma by Inhibiting Ferroptosis

Objective To investigate the effect of staphylococcal nuclease and tudor domain containing 1(SND1) on the biological function of osteosarcoma cells and decipher the mechanism of SND1 in regulating ferroptosis in osteosarcoma cells via SLC7A11. Methods Human osteoblasts hFOB1.19 and osteosarcoma cell lines Saos-2,U2OS,HOS,and 143B were cultured,in which the expression level of SND1 was determined.Small interfering RNA was employed to knock down the expression of SND1(si-SND1) in the osteosarcoma cell line HOS and 143B.The CCK8 assay kit,colony formation assay,and Transwell assay were employed to examine the effect of SND1 expression on the biological function of osteosarcoma cells.Furthermore,we altered the expression of SND1 and SLC7A11 in osteosarcoma cells to investigate the effect of SND1 on osteosarcoma ferroptosis via SLC7A11. Results The mRNA and protein levels of SND1 in Saos-2,U2OS,HOS,and 143B cells were higher than those in hFOB1.19 cells(all P<0.01).Compared with the control group,transfection with si-SND1 down-regulated the expression level of SND1 in HOS and 143B cells(all P<0.01),decreased the viability of HOS and 143B cells,reduced the number of colony formation,and inhibited cell invasion and migration(all P<0.001).The ferroptosis inducer Erastin promoted the apoptosis of HOS and 143B cells,while the ferroptosis inhibitor Ferrostatin-1 improved the viability of HOS and 143B cells(all P<0.001).After SND-1 knockdown,Erastin reduced the viability of HOS and 143B cells,while Ferrostatin-1 restored the cell viability(all P<0.001).After treatment with Erastin in the si-SND1 group,the levels of iron and malondialdehyde were elevated,and the level of glutathione was lowered(all P<0.001).The results of in vivo experiments showed that SND1 knockdown inhibited the mass of the transplanted tumor in 143B tumor-bearing nude mice(P<0.001).Knocking down the expression of SND1 resulted in down-regulated SLC7A11 expression(all P<0.001) and increased ferroptosis in HOS and 143B cells(P<0.001,P=0.020). Conclusions SND1 presents up-regulated expression in osteosarcoma cells.It may inhibit ferroptosis by up-regulating the expression of SLC7A11,thereby improving the viability of osteosarcoma cells.

KLF3 promotes colorectal cancer growth by activating WNT1.

The function of Kruppel-like factor 3 (KLF3) remains largely unexplored in colorectal cancer (CRC). KLF3 expression in CRC was assessed through qPCR, western blotting, immunohistochemical assays, and The Cancer Genome Atlas (TCGA) database. The tumor-promoting capacity of KLF3 was explored by performing in vitro functional experiments using CRC cells. A subcutaneous nude mouse tumor assay was employed to evaluate tumor growth. To further elucidate the interaction between KLF3 and other factors, luciferase reporter assay, agarose gel electrophoresis, and ChIP analysis were performed. KLF3 was downregulated in CRC tissue and cells. Silencing of KLF3 increased the potential of CRC cells for proliferation, migration, and invasion, while its activation decreased these processes. Downregulated KLF3 was associated with accelerated tumor growth in vivo. Mechanistically, KLF3 was discovered to target the promoter sequence of WNT1. Consequently, the diminished expression of KLF3 led to the buildup of WNT1 and the WNT/β-catenin pathway activation, consequently stimulating the progression of CRC. This investigation suggests that the involvement of KLF3/WNT1 regulatory pathway contributes to the progression of CRC, thereby emphasizing its promise as an important focus for future therapies aimed at treating CRC.

Comparison of Tumor Non-specific and PD-L1 Specific Imaging by Near-Infrared Fluorescence/Cerenkov Luminescence Dual-Modality In-situ Imaging.

Labeled antibodies are excellent imaging agents in oncology to non-invasively visualize cancer-related antigens expression levels. However, tumor tracer uptake (TTU) of specific antibodies in-vivo may be inferior to non-specific IgG in some cases. To explore factors affecting labeled antibody visualization by PD-L1 specific and non-specific imaging of nude mouse tumors. TTU was observed in RKO model on Cerenkov luminescence (CL) and near-infrared fluorescence (NIRF) imaging of radionuclide 131I or NIRF dyes labeled Atezolizumab and IgG. A mixture of NIRF dyes labeled Atezolizumab and 131I-labeled IgG was injected, and TTU was observed in the RKO and HCT8 model by NIRF/CL dual-modality in-situ imaging. TTU were observed by 131I-labeled Atezolizumab and IgG in-vitro distribution. Labeled IgG concentrated more in tumors than Atezolizumab. NIRF/CL imaging in 24 to 168 h showed that TTU gradually decreased over time, which decreased more slowly on CL imaging compared to NIRF imaging. The distribution data in-vitro showed that TTU of 131I-labeled IgG was higher than that of 131I-labeled Atezolizumab at any time point. Non-specific IgG may not be suitable as a control for Atezolizumab in comparing tumor PD-L1 expression in nude mice via labeled antibody optical imaging under certain circumstances.

Liensinine inhibits progression of intrahepatic cholangiocarcinoma by regulating TGF-β1 /P-smad3 signaling through HIF-1a.

Intrahepatic cholangiocarcinoma (ICC) is a high-grade malignant digestive system tumor with an insidious onset and unfavorable prognosis. Liensinine, a small molecule derived from plants, has been proven to have significant tumor suppressor activity in other cancers. However, there are no reports on whether liensinine can inhibit the proliferation or metastasis of ICC. This study aimed to explore the tumor-suppressive activity of liensinine in ICC and its underlying mechanisms. The phenotypic changes in ICC cells were monitored in vitro using cell function tests. Western blot and immunofluorescence analyses verified the efficacy of liensinine. Tumor-bearing nude mice were used to explore the effect of liensinine on tumors and its toxicity and side effects in vivo. Liensinine suppressed ICC cell proliferation and arrested the cell cycle at the G1 phase. The epithelial-mesenchymal transition (EMT) of ICC cells was also inhibited, thereby restraining their invasion and migration of tumor cells. In addition, this study found that the potential mechanism of liensinine inhibiting EMT may be via suppression of the TGF-β1/P-smad3 signaling pathway through hypoxia-inducible factor 1 alpha (HIF-1a). In vivo experiments showed that liensinine inhibited the growth of Hucc-T1 transplanted tumors in nude mice. Liensinine restrained the proliferation of ICC cells and suppressed EMT in ICC via the HIF-1a-mediated TGF-β1/P-smad3 signaling pathway.

HIV-1 Reverse Transcriptase Expression in HPV16-Infected Epidermoid Carcinoma Cells Alters E6 Expression and Cellular Metabolism, and Induces a Hybrid Epithelial/Mesenchymal Cell Phenotype.

The high incidence of epithelial malignancies in HIV-1 infected individuals is associated with co-infection with oncogenic viruses, such as high-risk human papillomaviruses (HR HPVs), mostly HPV16. The molecular mechanisms underlying the HIV-1-associated increase in epithelial malignancies are not fully understood. A collaboration between HIV-1 and HR HPVs in the malignant transformation of epithelial cells has long been anticipated. Here, we delineated the effects of HIV-1 reverse transcriptase on the in vitro and in vivo properties of HPV16-infected cervical cancer cells. A human cervical carcinoma cell line infected with HPV16 (Ca Ski) was made to express HIV-1 reverse transcriptase (RT) by lentiviral transduction. The levels of the mRNA of the E6 isoforms and of the factors characteristic to the epithelial/mesenchymal transition were assessed by real-time RT-PCR. The parameters of glycolysis and mitochondrial respiration were determined using Seahorse technology. RT expressing Ca Ski subclones were assessed for the capacity to form tumors in nude mice. RT expression increased the expression of the E6*I isoform, modulated the expression of E-CADHERIN and VIMENTIN, indicating the presence of a hybrid epithelial/mesenchymal phenotype, enhanced glycolysis, and inhibited mitochondrial respiration. In addition, the expression of RT induced phenotypic alterations impacting cell motility, clonogenic activity, and the capacity of Ca Ski cells to form tumors in nude mice. These findings suggest that HIV-RT, a multifunctional protein, affects HPV16-induced oncogenesis, which is achieved through modulation of the expression of the E6 oncoprotein. These results highlight a complex interplay between HIV antigens and HPV oncoproteins potentiating the malignant transformation of epithelial cells.

Curcumin Inhibits the Growth of Hepatocellular Carcinoma via the MARCH1-mediated Modulation of JAK2/STAT3 Signaling.

Curcumin has been reported to have anti-hepatocellular carcinoma (HCC) effects, but the underlying mechanism is not well known. To investigate whether membrane-associated RING-CH 1 (MARCH1) is involved in the curcumin-induced growth suppression in HCC and its underlying molecular mechanism. A few recent patents for curcumin for cancer are also reviewed in this article. The effect of curcumin on growth inhibition of HCC cells was analyzed through in vitro and in vivo experiments, and the expression levels of MARCH1, Bcl-2, VEGF, cyclin B1, cyclin D1, and JAK2/STAT3 signaling molecules were measured in HCC cells and the xenograft tumors in nude mice. Cell transfection with MARCH1 siRNAs or expression plasmid was used to explore the role of MARCH1 in the curcumin-induced growth inhibition of HCC cells. Curcumin inhibited cell proliferation, promoted apoptosis, and arrested the cell cycle at the G2/M phase in HCC cells with the decrease of Bcl-2, VEGF, cyclin B1, and cyclin D1 expression as well as JAK2 and STAT3 phosphorylation, resulting in the growth suppression of HCC cells. MARCH1 is highly expressed in HCC cells, and its expression was downregulated after curcumin treatment in a dose-dependent manner. The knockdown of MARCH1 by siRNA decreased the phosphorylation levels of JAK2 and STAT3 and inhibited the growth of HCC cells. In contrast, opposite results were observed when HCC cells overexpressed MARCH1. A xenograft tumor model in nude mice also showed that curcumin downregulated MARCH1 expression and decelerated the growth of transplanted HCC with the downregulation of JAK2/STAT3 signaling and functional molecules. The ADC value of MRI analysis showed that curcumin slowed down the progression of HCC. Our results demonstrated that curcumin may inhibit the activation of JAK2/STAT3 signaling pathway by downregulating MARCH1 expression, resulting in the growth suppression of HCC. MARCH1 may be a novel target of curcumin in HCC treatment.