Xenograft Growth In Mice Research Articles

Preclinical evaluation of Mito-LND, a targeting mitochondrial metabolism inhibitor, for glioblastoma treatment

BackgroundGlioblastoma (GBM) is a brain tumor with the highest level of malignancy and the worst prognosis in the central nervous system. Mitochondrial metabolism plays a vital role in the occurrence and development of cancer, which provides critical substances to support tumor anabolism. Mito-LND is a novel small-molecule inhibitor that can selectively inhibit the energy metabolism of tumor cells. However, the therapeutic effect of Mito-LND on GBM remains unclear.MethodsThe present study evaluated the inhibitory effect of Mito-LND on the growth of GBM cells and elucidated its potential mechanism.ResultsThe results showed that Mito-LND could inhibit the survival, proliferation and colony formation of GBM cells. Moreover, Mito-LND induced cell cycle arrest and apoptosis. Mechanistically, Mito-LND inhibited the activity of mitochondrial respiratory chain complex I and reduced mitochondrial membrane potential, thus promoting ROS generation. Importantly, Mito-LND could inhibit the malignant proliferation of GBM by blocking the Raf/MEK/ERK signaling pathway. In vivo experiments showed that Mito-LND inhibited the growth of GBM xenografts in mice and significantly prolonged the survival time of tumor-bearing mice.ConclusionTaken together, the current findings support that targeting mitochondrial metabolism may be as a potential and promising strategy for GBM therapy, which will lay the theoretical foundation for further clinical trials on Mito-LND in the future.

Exosome-Mediated Activation of the Prostasin-Matriptase Serine Protease Cascade in B Lymphoma Cells.

Prostasin and matriptase are extracellular membrane serine proteases with opposing effects in solid epithelial tumors. Matriptase is an oncoprotein that promotes tumor initiation and progression, and prostasin is a tumor suppressor that reduces tumor invasion and metastasis. Previous studies have shown that a subgroup of Burkitt lymphoma have high levels of ectopic matriptase expression but no prostasin. Reducing the matriptase level via small interfering RNAs in B lymphoma cells impeded tumor xenograft growth in mice. Here, we report a novel approach to matriptase regulation in B cancer cells by prostasin via exosomes to initiate a prostasin-matriptase protease activation cascade. The activation and shedding of matriptase were monitored by measuring its quantity and trypsin-like serine protease activity in conditioned media. Sustained activation of the protease cascade in the cells was achieved by the stable expression of prostasin. The B cancer cells with prostasin expression presented phenotypes consistent with its tumor suppressor role, such as reduced growth and increased apoptosis. Prostasin exosomes could be developed as an agent to initiate the prostasin-matriptase cascade for treating B lymphoma with further studies in animal models.

Discovery of an OTUD3 inhibitor for the treatment of non-small cell lung cancer

The ubiquitin-proteasome system (UPS) controls protein turnover, and its dysfunction contributes to human diseases including cancer. Deubiquitinating enzymes (DUBs) remove ubiquitin from proteins to maintain their stability. Inhibition of DUBs could induce the degradation of selected oncoproteins and has therefore become a potential therapeutic strategy for cancer. The deubiquitylase OTUD3 was reported to promote lung tumorigenesis by stabilizing oncoprotein GRP78, implying that inhibition of OTUD3 may be a therapeutic strategy for lung cancer. Here, we report a small-molecule inhibitor of OTUD3 (named OTUDin3) by computer-aided virtual screening and biological experimental verification. OTUDin3 exhibited pronounced antiproliferative and proapoptotic effects by inhibiting deubiquitinating activity of OTUD3 in non-small-cell lung cancer (NSCLC) cell lines. Moreover, OTUDin3 efficaciously inhibited growth of lung cancer xenografts in mice. In summary, our results support OTUDin3 as a potent inhibitor of OTUD3, the inhibition of which may be a promising therapeutic strategy for NSCLC.

Competition between p53 and YY1 determines PHGDH expression and malignancy in bladder cancer.

Serine metabolism is frequently dysregulated in many types of cancers and the tumor suppressor p53 is recently emerging as a key regulator of serine metabolism. However, the detailed mechanism remains unknown. Here, we investigate the role and underlying mechanisms of how p53 regulates the serine synthesis pathway (SSP) in bladder cancer (BLCA). Two BLCA cell lines RT-4 (WT p53) and RT-112 (p53 R248Q) were manipulated by applying CRISPR/Cas9 to examine metabolic differences under WT and mutant p53 status. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and non-targeted metabolomics analysis were adopted to identify metabolomes changes between WT and p53 mutant BLCA cells. Bioinformatics analysis using the cancer genome atlas and Gene Expression Omnibus datasets and immunohistochemistry (IHC) staining was used to investigate PHGDH expression. Loss-of-function of PHGDH and subcutaneous xenograft model was adopted to investigate the function of PHGDH in mice BLCA. Chromatin immunoprecipitation (Ch-IP) assay was performed to analyze the relationships between YY1, p53, SIRT1 and PHGDH expression. SSP is one of the most prominent dysregulated metabolic pathways by comparing the metabolomes changes between wild-type (WT) p53 and mutant p53 of BLCA cells. TP53 gene mutation shows a positive correlation with PHGDH expression in TCGA-BLCA database. PHGDH depletion disturbs the reactive oxygen species homeostasis and attenuates the xenograft growth in the mouse model. Further, we demonstrate WT p53 inhibits PHGDH expression by recruiting SIRT1 to the PHGDH promoter. Interestingly, the DNA binding motifs of YY1 and p53 in the PHGDH promoter are partially overlapped which causes competition between the two transcription factors. This competitive regulation of PHGDH is functionally linked to the xenograft growth in mice. YY1 drives PHGDH expression in the context of mutant p53 and promotes bladder tumorigenesis, which preliminarily explains the relationship between high-frequency mutations of p53 and dysfunctional serine metabolism in bladder cancer.

Vitamin C Enhances Anticancer Immunity

The molecular mechanisms underlying vitamin C’s anticancer activity remain unclear. Recently, multiple high-quality studies demonstrated several potentially novel functions of vitamin C in regulating anticancer immunity, including modulating T cell infiltration of tumor microenvironment as well as increasing cancer cell immunogenicity. (First online: June 4, 2023) REFERENCES Creagan ET, Moertel CG, O'Fallon JR, Schutt AJ, O'Connell MJ, Rubin J, et al. Failure of high-dose vitamin C (ascorbic acid) therapy to benefit patients with advanced cancer: a controlled trial. N Engl J Med 1979; 301(13):687–90. doi: https://dx.doi.org/10.1056/NEJM197909273011303 Moertel CG, Fleming TR, Creagan ET, Rubin J, O'Connell MJ, Ames MM. High-dose vitamin C versus placebo in the treatment of patients with advanced cancer who have had no prior chemotherapy: a randomized double-blind comparison. N Engl J Med 1985; 312(3):137–41. doi: https://dx.doi.org/10.1056/NEJM198501173120301 Lin J, Cook NR, Albert C, Zaharris E, Gaziano JM, Van Denburgh M, et al. Vitamins C and E and beta carotene supplementation and cancer risk: a randomized controlled trial. J Natl Cancer Inst 2009; 101(1):14–23. doi: https://dx.doi.org/10.1093/jnci/djn438 Chen Q, Espey MG, Sun AY, Pooput C, Kirk KL, Krishna MC, et al. Pharmacologic doses of ascorbate act as a prooxidant and decrease growth of aggressive tumor xenografts in mice. Proc Natl Acad Sci USA 2008; 105(32):11105–9. doi: https://dx.doi.org/10.1073/pnas.0804226105 Yun J, Mullarky E, Lu C, Bosch KN, Kavalier A, Rivera K, et al. Vitamin C selectively kills KRAS and BRAF mutant colorectal cancer cells by targeting GAPDH. Science 2015; 350(6266):1391–6. doi: https://dx.doi.org/10.1126/science.aaa5004 Magri A, Germano G, Lorenzato A, Lamba S, Chila R, Montone M, et al. High-dose vitamin C enhances cancer immunotherapy. Sci Transl Med 2020; 12(532). doi: 10.1126/scitranslmed.aay8707. Xu YP, Lv L, Liu Y, Smith MD, Li WC, Tan XM, et al. Tumor suppressor TET2 promotes cancer immunity and immunotherapy efficacy. J Clin Invest 2019; 129(10):4316–31. doi: https://dx.doi.org/10.1172/JCI129317 Wu X, Zhang Y. TET-mediated active DNA demethylation: mechanism, function and beyond. Nat Rev Genet 2017; 18(9):517–34. doi: https://dx.doi.org/10.1038/nrg.2017.33 Luchtel RA, Bhagat T, Pradhan K, Jacobs WR, Jr., Levine M, Verma A, et al. High-dose ascorbic acid synergizes with anti-PD1 in a lymphoma mouse model. Proc Natl Acad Sci USA 2020; 117(3):1666–77. doi: https://dx.doi.org/10.1073/pnas.1908158117 Morante-Palacios O, Godoy-Tena G, Calafell-Segura J, Ciudad L, Martinez-Caceres EM, Sardina JL, et al. Vitamin C enhances NF-kappaB-driven epigenomic reprogramming and boosts the immunogenic properties of dendritic cells. Nucleic Acids Res 2022; 50(19):10981–94. doi: https://dx.doi.org/10.1093/nar/gkac941

Ponicidin Induces Apoptosis of Murine Melanoma by Inhibiting the NF-κB Signaling Pathway.

Ponicidin (PON), a diterpenoid extracted from the Chinese herb Rubescens, has been reported to be a therapeutic cytotoxic drug for the treatment of various types of human cancers. According to the statistics, the incidence of malignant melanoma is increasing year by year and the degree of malignancy is extremely high, so early treatment is very important. In the present study, we demonstrated the antitumor effect of PON on melanoma in vitro and in vivo. Cell Counting Kit-8 (CCK-8) assay was used to detect cell proliferation rate, crystal violet staining and TdT-mediated dUTP Nick-End Labeling (TUNEL) kit was used to detect cell apoptosis, and Western blotting was used to detect the expression of apoptotic indicators and related signaling pathway proteins. Finally, the tumor-bearing mouse model was constructed. Treating melanoma B16F0 and B16F10 cells with different concentrations (10 and 20 µmol/L) of PON magnificantly decreased cell viability. In addition, PON significantly activates the expression of pro-apoptotic proteins, including cleaved-poly(ADP-ribose)polymerase (PARP) (cl.PARP), Bak and Bim proteins, and also inhibits the expression of anti-apoptotic protein Mcl-1 and nuclear transcription factor nuclear factor-kappaB (NF-κB) in melanoma cells. Lastly, PON effectively inhibits the growth of mouse xenografts in vivo. These results suggest that PON induces apoptosis of melanoma cells may be achieved by inhibiting NF-κB signal pathway, but the specific mechanism remains to be further elucidated. Taken together, PON may serve as an effective potential drug for the treatment of melanoma.

Metformin-based carbon dots based on biguanide functional groups for simultaneous chelation of copper ions and inhibitable colorectal cancer therapy

Colorectal cancer (CRC) is the most common malignancy-related cause of death worldwide. The prognosis of CRC patients is strongly correlated with elevated plasma copper. The quantitative detection of plasma copper is highly essential for the field of biomedicine, and our hypothesis was that plasma copper may be a therapeutic target for treating CRC. Here, we developed metformin-based carbon dots (MFCDs). MFCDs have strong photoluminescence at 460 nm, which is quenched by Cu2+. Cu2+ concentration and the fluorescence emission intensity of MFCDs are significantly associated (linear range of 0.5–40 μM with a detection limit of 0.30 μM). Additionally, administration of MFCDs significantly inhibited the growth of CRC xenografts in mice caused by the existence of biguanide functional groups. MFCDs treatment led to the increase of reactive oxygen species and subsequent DNA damage and cell cycle arrest. This study showed that the biguanide functional groups of MFCDs chelate with Cu2+, resulting in the reduction of Cu/Zn-superoxide dismutase and glutathione, which eventually reduces antioxidant capacity and ultimately induces cell apoptosis. These results indicate that MFCDs provide a novel approach for anticancer therapy.

Abstract 2611: p63 constrains cancer cell transposable element expressions and viral mimicry response to sustain esophageal cancer development and indicates therapeutic vulnerability

Abstract Background: Esophageal squamous cell carcinoma (ESCC) is the predominant form of esophageal cancer in developing areas and is among the top 10 deadliest cancers with a dismal 5-year survival rate of 10~20%. ESCC molecular pathogenesis has not been well characterized, while chemoradiotherapy remains the routine treatment option besides surgery, highlighting the need for a thorough understanding of ESCC and new treatment options. Tumor protein p63 (TP63), encoding p63, plays fundamental roles in stratified epithelial homeostasis. In the esophagus, ΔNp63 is the predominant isoform and is required for normal epithelial development. ESCC retains high ΔNp63 expression level, but its contribution to ESCC development is not fully understood. Results: We found ΔNp63 maintains ESCC development, depletion of which results in great attenuation and regression of cell line-derived xenograft growth in mice. Transcriptomic profiling showed type-I interferon (IFN-I) signaling-related pathways are the top pathways enriched in ΔNp63-depleted cells. This was further verified by quantitative PCR confirming up-regulations of interferon-stimulated genes upon ΔNp63 depletion in cell lines, and by transcriptomic profiling on our latest panel of naïve ESCC patient-derived organoids (PDOs) showing TP63 expression level negatively associated with IFN-I signaling-related pathways. Elevated endogenous retrotransposon-encoded RNA expression induces cancer cell IFN-I signaling through mediating tumor-suppressive viral mimicry response, an anti-viral state triggered by endogenous stimuli (1). We found cancer cell ΔNp63 depletion results in increased retrotransposon expression triggering dsRNA sensing and downstream signaling activation; Interferon regulatory factor 1 plays a critical role in mediating viral mimicry response downstream of ΔNp63. We further showed cells with lower ΔNp63 level and higher IFN-I signaling activity (ΔNp63-depleted cell lines and ΔNp63lo PDOs) display stronger responses to Decitabine, an anti-cancer drug and viral mimicry booster (1), as compared to control cell lines or ΔNp63hi PDOs, respectively. Conclusion: We identified a novel function of ΔNp63 in repressing cancer retrotransposon expression and explored the therapeutic potential of enhancing viral mimicry response, which may guide future ΔNp63/viral mimicry response-targeted therapy. Acknowledgement: We acknowledge the Research Grants Council (TRS T12-701/17-R to MLL) and the Food and Health Bureau (HMRF 06171566 to VZY) of Hong Kong SAR for funding supports. We acknowledge DSMZ for the KYSE cell lines. We acknowledge the HKUMed-CPOS for providing imaging facilities. Reference: 1.Chiappinelli KB, et al. Inhibiting DNA Methylation Causes an Interferon Response in Cancer via dsRNA Including Endogenous Retroviruses. Cell 2015 Citation Format: Valen Zhuoyou Yu, Shan Shan So, Bryan Chee-Chad Lung, Carissa Wing-Yan Wong, Ian Yu-Hong Wong, Claudia Lai-Yin Wong, Desmond Kwan-Kit Chan, Fion Siu-Yin Chan, Betty Tsz-Ting Law, Ka-On Lam, Anthony Wing-Ip Lo, Josephine Mum-Yee Ko, Wei Dai, Alfred King-Yin Lam, Dora Lai-Wan Kwong, Simon Law, Maria Li Lung. p63 constrains cancer cell transposable element expressions and viral mimicry response to sustain esophageal cancer development and indicates therapeutic vulnerability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2611.

Abstract 2580: Nuclear receptor coactivator 3 (NCOA3) fuels oncogenic pathways in uveal melanoma

Abstract Background: Uveal melanoma (UM) originates from melanocytes residing in the uveal tract of an eye. Despite effective local control, approximately half of patients develop metastatic disease resistant to systemic chemotherapy and presenting poor response to immunotherapy or targeted therapy. UM patients have a median overall survival of 6 to 12 months. The basis of the pathogenesis of UM are mutations in GNAQ and GNA11 genes resulting in constitutive activation of PKC/MAPK signaling. Here, we analyzed the role of NCOA3, a transcription factor coactivator that was previously shown to be modified by PKC in multiple cancer, as a factor potentiating oncogenic outcome of multiple oncogenic pathways activated in UM downstream of GNAQ or GNA11. Methods: We examined the impact of altered NCOA3 mRNA in UM, using publicly available TCGA dataset. Next, we used CRISPR/Cas9 technology to delete NCOA3 protein in MP41 UM cell line. We evaluated proliferation of MP41/NCOA3 KO cell subline and its parental counterpart in vitro by a colony formation assay. Next, we analyzed growth of xenografts of MP41/NCOA3 KO and parental cells in SCID/beige mice. To understand the molecular consequences of NCOA3 activity in UM, we performed a genome wide comparison of gene expression in MP41/NCOA3 KO and parental cells. Functional enrichment analysis was used to identify classes of genes associated with NCOA3 activity and determine similarities with datasets obtained by targeting proteins of GNAQ/GNA11 pathways and inhibiting activity of NCOA3 using a tool small molecule inhibitor SI-2 in UM cell lines. Results: We found that NCOA3 overexpression negatively correlated with UM patients’ progression free and overall survival. Knockout of NCOA3 gene in MP41 UM cells substantially reduced their proliferation in vitro and xenograft growth in mice. Global gene expression analysis revealed that NCOA3 activity is linked with transcriptional signatures associated with cell mitotic activity (cell cycle and DNA replication) and transcriptional machinery binding (especially affecting E2F and myc regulated programs). The MP41 NCOA3 KO normalized enrichment scores (NES) show high concordance with NES obtained after silencing GNAQ or GNA11 in UM cell lines and pharmacological targeting PKC or NCOA3. Conclusions: Inhibition of NCOA3 activity inhibits several oncogenic pathways in a concerted manner, limiting UM cell survival and tumor growth. Our results deliver proof of concept that NCOA3 is a master transcriptional co-regulator of oncogenic signaling in uveal melanoma and a potential therapeutic target. Citation Format: Aleksandra Rusin, Maria E. Ruiz Echartea, Darlene G. Skapura, Karen Berman deRuiz, Christel M. Davis, Eric A. Ehli, Sandra L. Grimm, Christian Coarfa, Salma Kaochar. Nuclear receptor coactivator 3 (NCOA3) fuels oncogenic pathways in uveal melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2580.

Abstract 1375: Paranuclear retention of c-KIT by Merkel cell polyomavirus large T-antigen suppresses autophagy through interaction with Beclin 1 essential for Merkel cell carcinoma cell survival

Abstract Merkel cell carcinoma (MCC) is a very aggressive skin cancer most commonly caused by Merkel cell polyomavirus (MCPyV). While the strong expression of the human proto-oncogene c-KIT in MCC is well established, the functional relevance of this expression is unknown. Here, we demonstrate that paranuclear presence of c-KIT suppresses autophagy which is essential for maintenance of MCC cells. Specifically, after its phosphorylation, c-KIT traffics by clathrin-dependent endocytosis to late endosomes where it is sequestered in the paranuclear compartment by the MCPyV-encoded large transforming antigen (LT) via its Vam6p binding site, which also blocks c-KIT's lysosomal degradation. In this paranuclear compartment, c-KIT interacts directly with both the BH3 and the evolutionarily conserved domain (ECD) of Beclin 1, decreasing its binding to VPS34 and increasing its binding to BCL2, resulting in suppression of autophagy. Indeed, silencing of c-KIT induces autophagy and apoptosis in MCPyV-positive MCC cell lines. It is noteworthy that the positive feedback loop of LT and c-KIT also applies in the reverse direction, as LT is degraded via autophagy. This notion explains why an autophagy-inducing peptide efficiently induces apoptosis-independent cell death and inhibits tumor growth of MCC xenografts in mice. In conclusion, we identified a novel mechanism of MCPyV LT to suppress autophagy through sequestering and stabilizing c-KIT in the paranuclear compartment, which is mandatory to maintain the oncogenic phenotype of MCC cells. Autophagy-inducing agents therefore represent a therapeutic strategy for patients with advanced MCPyV-associated MCC. Citation Format: Hao Shi, Yajie Yang, Catharina Larsson, Weng-Onn Lui. Paranuclear retention of c-KIT by Merkel cell polyomavirus large T-antigen suppresses autophagy through interaction with Beclin 1 essential for Merkel cell carcinoma cell survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1375.

Baicalein suppresses HER2-mediated malignant transformation of HER2-overexpressing ovarian cancer cells by downregulating HER2 gene expression.

The upregulation of the HER2 oncogene is associated with a variety of human cancers and is associated with poor prognosis. Baicalein is reported to have anti-tumor activity, but the molecular mechanism of this effect in HER2-positive cancer cells has not been studied. In this study, our data showed that baicalein can inhibit the proliferation and transformation potential of ovarian cancer cells overexpressing HER2. Baicalein treatment caused a dose-dependent inhibition of HER2 gene expression at the transcriptional level. Baicalein acted on ovarian cancer cells overexpressing HER2 to downregulate the PI3K/Akt signaling pathway downstream of HER2 and inhibit the expression or activity of downstream targets, such as VEGF and cyclin D1 and MMP2. Oral administration of baicalein supplemented with a pharmaceutical excipient significantly inhibited the growth of HER2-overexpressing ovarian SKOV-3 cancer xenografts in mice. These results suggest that downregulation of HER2 gene expression by baicalein at the transcriptional level contributes to inhibit the in vitro and in vivo proliferation and HER2-mediated malignant transformation of HER2-overexpressing ovarian cancer cells.

Disulfiram enhances cisplatin cytotoxicity by forming a novel platinum chelate Pt(DDTC)3+

Despite the use of targeted therapy in non-small cell lung cancer (NSCLC) patients, cisplatin (DDP)-based chemotherapy is still the main option. However, DDP resistance is the major factor contributing to the failure of chemotherapy. In this study, we tried to screen DDP sensitizers from an FDA-approved drug library containing 1374 small-molecule drugs to overcome DDP resistance in NSCLC. As a result, disulfiram (DSF) was identified as a DDP sensitizer: DSF and DDP had synergistic anti-NSCLC effects, which are mainly reflected in inhibiting tumor cell proliferation, plate colony formation and 3D spheroidogenesis and inducing apoptosis in vitro, as well as the growth of NSCLC xenografts in mice. Although DSF has recently been reported to promote the antitumor effect of DDP by inhibiting ALDH activity or modulating some important factors or pathways, unexpectedly, we found that DSF reacted with DDP to form a new platinum chelate, Pt(DDTC)3+, which might be one of the important mechanisms for their synergistic effect. Moreover, Pt(DDTC)3+ has a stronger anti-NSCLC effect than DDP, and its antitumor activity is broad-spectrum. These findings reveal a novel mechanism underlying the synergistic antitumor effect of DDP and DSF, and provide a drug candidate or a lead compound for the development of a new antitumor drug.

A Novel Homodimer Peptide–Drug Conjugate Improves the Efficacy of HER2-Positive Breast Cancer Therapy

Tumor-targeting peptide-drug conjugates (PDCs) have become a focus of research in recent years. However, due to the instability of peptides and their short in vivo effective half-life, they have limited clinical application. Herein, we propose a new DOX PDC based on a homodimer HER-2-targeting peptide and acid-sensitive hydrazone bond, which could enhance the anti-tumor effect of DOX and reduce systemic toxicities. The PDC could accurately deliver DOX into HER2-positive SKBR-3 cells, with it showing 2.9 times higher cellular uptake than free DOX and enhanced cytotoxicity with respect to IC50 of 140 nM (vs. 410 nM for free DOX). In vitro assays showed that the PDC had high cellular internalization efficiency and cytotoxicity. In vivo anti-tumor experiments indicated that the PDC could significantly inhibit the growth of HER2-positive breast cancer xenografts in mice and reduce the side effects of DOX. In summary, we constructed a novel PDC molecule targeting HER2-positive tumors, which may overcome some deficiencies of DOX in breast cancer therapy.

Ribosomal protein L31 (RPL31) inhibits the proliferation and migration of gastric cancer cells

Gastric cancer (GC) is a digestive tract malignant tumor and causes the third cancer-related mortality in the world. Aberrant expression of Ribosomal Protein L31 (RPL31) has been reported in several human cancers. The aim of this study was to explore the role and possible biological functions of RPL31 in GC. We firstly employed immunohistochemistry to examine RPL31 expression in tumor and para-cancerous tissues. By lentiviral transfection, we successfully constructed an RPL31-knockdown GC cell model and performed functional validation to reveal the effects of RPL31 on proliferation, apoptosis, cycle, migration, and tumor growth. Our data indicated that RPL31 was abundantly expressed in GC tissues and cell lines (AGS and MGC-803). In addition, RPL31 expression was positively correlated with the extent of tumor infiltrate of GC patients. Functionally, silencing RPL31 in AGS and MGC-803 cells significantly limited the ability of proliferation and migration, promoted cell apoptosis. Consistently, RPL31-knockdown GC cells inhibited the growth of xenografts in mice. Moreover, preliminary analysis on the downstream regulation mechanism revealed that RPL31 functioned as a tumor promoter through targeting JAK-STAT signaling pathway. In conclusion, inhibition of abnormally high expression of RPL31 in GC may be a potential therapeutic strategy for this disease.

SLC5A3 is important for cervical cancer cell growth.

Novel molecular targets for cervical cancer must be identified. This study examined the role of SLC5A3, a myo-inositol transporter, in the pathogenesis of cervical cancer. Through boinformatics analysis, we showed that the SLC5A3 mRNA levels were upregulated in cervical cancer tissues. The upregulated SLC5A3 mRNA levels were negatively correlated with survival and progression-free interval. Genes co-expressed with SLC5A3 were enriched in multiple signaling cascades involved in cancer progression. In primary/established cervical cancer cells, SLC5A3 shRNA/knockout (KO) exerted growth-inhibitory effects and promoted cell death/apoptosis. Furthermore, SLC5A3 knockdown or KO downregulated myo-inositol levels, induced oxidative injury, and decreased Akt-mTOR activation in cervical cancer cells. In contrast, supplementation of myo-inositol or n-acetyl-L-cysteine or transduction of a constitutively active Akt1 construct mitigated SLC5A3 KO-induced cytotoxicity in cervical cancer cells. Lentiviral SLC5A3 overexpression construct transduction upregulated the cellular myo-inositol level and promoted Akt-mTOR activation, enhancing cervical cancer cell proliferation and migration. The binding of TonEBP to the SLC5A3 promoter was upregulated in cervical cancer. In vivo studies showed that intratumoral injection of SLC5A3 shRNA-expressing virus arrested cervical cancer xenograft growth in mice. SLC5A3 KO also inhibited pCCa-1 cervical cancer xenograft growth. The SLC5A3-depleted xenograft tissues exhibited myo-inositol downregulation, Akt-mTOR inactivation, and oxidative injury. Transduction of sh-TonEBP AAV construct downregulated SLC5A3 expression and inhibited pCCa-1 cervical cancer xenograft growth. Together, overexpressed SLC5A3 promotes growth of cervical cancer cells, representing as a novel therapeutic oncotarget for the devastating disease.

Comprehensive Analysis of Sideroflexin 4 in Hepatocellular Carcinoma by Bioinformatics and Experiments.

Background: Sideroflexins (SFXNs) are a family of highly conserved mitochondrial transporters which regulate iron homeostasis and mitochondrial respiratory chain. However, the roles and mechanisms of SFXNs in HCC remain unknown. Methods: SFXNs expression and prognostic value in HCC was comprehensively analyzed. Proteins interacting with SFXN4 were analyzed in STRING database. The co-expression genes of SFXN4 were analyzed in cBioPortal database, and function of SFXN4 co-expression genes were annotated. The putative transcription factors and miRNA targeting SFXN4 were analyzed in NetworkAnalyst. The correlation between SFXN4 expression and immune infiltration was analyzed by ssGSEA. Cancer pathway activity and drug sensitivity related to SFXN4 were explored in GSCALite. The roles of SFXN4 in proliferation, migration and invasion of HCC were assessed in vitro and in vivo. Results: SFXN4 was consistently elevated in HCC, positively correlated with clinicopathological characteristics and predicted poor outcome. Functional enrichment showed SFXN4 was mainly related to oxidative phosphorylation, reactive oxygen species and metabolic pathways. SFXN4 expression was regulated by multiple transcription factors and miRNAs, and SFXN4 expression in HCC was associated with several cancer pathways and drug sensitivity. SFXN4 expression correlated with immune infiltration in HCC. In vitro, knockdown of SFXN4 inhibited HCC proliferation, migration and invasion, and decreased the expression of cyclin D1 and MMP2. In vivo, knockdown of SFXN4 inhibited the growth of tumor xenografts in mice. Conclusion: SFXN4 was upregulated in HCC, predicted poor prognosis, and may facilitate HCC development and progression via various mechanisms. For HCC, SFXN4 may provide both prognostic information and therapeutic potential.

Endothelial cell-specific molecule 1 drives cervical cancer progression

The expression, biological functions and underlying molecular mechanisms of endothelial cell-specific molecule 1 (ESM1) in human cervical cancer remain unclear. Bioinformatics analysis revealed that ESM1 expression was significantly elevated in human cervical cancer tissues, correlating with patients’ poor prognosis. Moreover, ESM1 mRNA and protein upregulation was detected in local cervical cancer tissues and various cervical cancer cells. In established and primary cervical cancer cells, ESM1 shRNA or CRISPR/Cas9-induced ESM1 KO hindered cell proliferation, cell cycle progression, in vitro cell migration and invasion, and induced significant apoptosis. Whereas ESM1 overexpression by a lentiviral construct accelerated proliferation and migration of cervical cancer cells. Further bioinformatics studies and RNA sequencing data discovered that ESM1-assocaited differentially expressed genes (DEGs) were enriched in PI3K-Akt and epithelial-mesenchymal transition (EMT) cascades. Indeed, PI3K-Akt cascade and expression of EMT-promoting proteins were decreased after ESM1 silencing in cervical cancer cells, but increased following ESM1 overexpression. Further studies demonstrated that SYT13 (synaptotagmin 13) could be a primary target gene of ESM1. SYT13 silencing potently inhibited ESM1-overexpression-induced PI3K-Akt cascade activation and cervical cancer cell migration/invasion. In vivo, ESM1 knockout hindered SiHa cervical cancer xenograft growth in mice. In ESM1-knockout xenografts tissues, PI3K-Akt inhibition, EMT-promoting proteins downregulation and apoptosis activation were detected. In conclusion, overexpressed ESM1 is important for cervical cancer growth in vitro and in vivo, possibly by promoting PI3K-Akt activation and EMT progression. ESM1 represents as a promising diagnostic marker and potential therapeutic target of cervical cancer.

LCMT1 indicates poor prognosis and is essential for cell proliferation in hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is one of the most malignant type of cancers. Leuci carboxyl methyltransferase 1 (LCMT1) is a protein methyltransferase that plays an improtant regulatory role in both normal and cancer cells. The aim of this study is to evaluate the expression pattern and clinical significance of LCMT1 in HCC. MethodsThe expression pattern and clinical relevance of LCMT1 were determined using the Gene Expression Omnibus (GEO) database, the Cancer Genome Atlas (TCGA) program, and our datasets. Gain-of-function and loss-of-function studies were employed to investigate the cellular functions of LCMT1 in vitro and in vivo. Quantitative real-time polymerase chain reaction (RT-PCR) analysis, western blotting, enzymatic assay, and high-performance liquid chromatography were applied to reveal the underlying molecular functions of LCMT1. ResultsLCMT1 was upregulated in human HCC tissues, which correlated with a “poor” prognosis. The siRNA-mediated knockdown of LCMT1 inhibited glycolysis, promoted mitochondrial dysfunction, and increased intracellular pyruvate levels by upregulating the expression of alani-neglyoxylate and serine-pyruvate aminotransferase (AGXT). The overexpression of LCMT1 showed the opposite results. Silencing LCMT1 inhibited the proliferation of HCC cells in vitro and reduced the growth of tumor xenografts in mice. Mechanistically, the effect of LCMT1 on the proliferation of HCC cells was partially dependent on PP2A. ConclusionsOur data revealed a novel role of LCMT1 in the proliferation of HCC cells. In addition, we provided novel insights into the effects of glycolysis-related pathways on the LCMT1regulated progression of HCC, suggesting LCMT1 as a novel therapeutic target for HCC therapy.

Glioblastoma stem cell-specific histamine secretion drives pro-angiogenic tumor microenvironment remodeling.

The communication between glioblastoma stem cells (GSCs) and the surrounding microenvironment is a prominent feature accounting for the aggressive biology of glioblastoma multiforme (GBM). However, the mechanisms by which GSCs proactively drive interactions with microenvironment is not well understood. In this study, we interrogated metabolites that are preferentially secreted from GSCs and found that GSCs produce and secrete histamine to shape a pro-angiogenic tumor microenvironment. This histamine-producing ability is attributed to H3K4me3 modification-activated histidine decarboxylase (HDC) transcription via MYC. Notably, HDC is highly expressed in GBM, which is associated with poor survival of these patients. GSC-secreted histamine activates endothelial cells by triggering a histamine H1 receptor (H1R)-Ca2+-NF-κB axis, thereby promoting angiogenesis and GBM progression. Importantly, pharmacological blockage of H1R using antihistamines impedes the growth of GBM xenografts in mice. Our findings establish that GSC-specific metabolite secretion remodels the tumor microenvironment and highlight histamine targeting as a potential strategy for GBM therapy.

Integrated network pharmacology and serum metabolomics approach deciphers the anti-colon cancer mechanisms of Huangqi Guizhi Wuwu Decoction.

Huangqi Guizhi Wuwu Decoction (HGWD), as a classic Chinese herbal decoction, has been widely used in treating various diseases for hundreds of years. However, systematically elucidating its mechanisms of action remains a great challenge to the field. In this study, taking advantage of the network pharmacology approach, we discovered a potential new use of HGWD for patients with colon cancer (CC). Our in vivo result showed that orally administered HGWD markedly inhibited the growth of CC xenografts in mice. The subsequent enrichment analyses for the core therapeutic targets revealed that HGWD could affect multiple biological processes involving CC growth, such as metabolic reprogramming, apoptosis and immune regulation, through inhibiting multiple cell survival-related signalings, including MAPK and PI3K-AKT pathways. Notably, these in silico analysis results were most experimentally verified by a series of in vitro assays. Furthermore, our results based on serum metabolomics showed that the lipid metabolic pathways, including fatty acid biosynthesis and cholesterol metabolism, play key roles in delivery of the anti-CC effect of HGWD on tumor-bearing mice, and that cytochrome P450 family 2 subfamily E member 1 (CYP2E1) is a potential therapeutic target. Together, our integrated approach reveals a therapeutic effect of HGWD on CC, providing a valuable insight into developing strategies to predict and interpret the mechanisms of action for Chinese herbal decoctions.