miR-29b Derived from Bone Marrow Stromal Cell (BMSC) Exosomes Improves Laryngeal Carcinoma by Inhibiting Forkhead Box Protein P1 (FOXP1) to Decrease Cyclin E2 Transcription

This study intends to investigate whether miR-29b derived from BMSC exosomes (BMSC-exos) affects laryngeal cancer progression. RT-qPCR detected miR-29b level in BMSCs and BMSC-exos. After miR-29b was overexpressed in BMSCs, exos were extracted from BMSCs and used to treat laryngeal cancer cells, followed by CCK-8 assay and soft agar assay. When cells were treated with FOXP1 inhibitor or cyclin E2 vector, Western blot analyzed the expression of related proteins and flow cytometry assessed cell cycle distribution. In vivo experiment was conducted to assess miR-29b’s effect on tumor growth. miR-29b was upregulated in BMSC-exos, but lowly expressed in cancer cells. miR-29b upregulation inhibited the proliferation of laryngeal cancer cells and delayed tumor progression In vivo by inducing cell cycle arrest. Importantly, miR-29b bound 3′UTR of FXOP1 to inhibit its expression, and further reduced cyclin E2 level. sh-FXOP1 or cyclin E2 vector can restore the cell cycle and proliferation caused by miR-29b. In conclusion, miR-29b enriched in BMSC-exo can down-regulate cyclin E2 expression through targeted inhibition of FXOP1, thereby inhibiting the progression of laryngeal cancer.

Design, Synthesis, Biological Evaluation and Molecular Docking Studies of 5-fluorouracil-dithiocarbamate Conjugates

In this paper, a series of novel 5-fluorouracil-dithiocarbamate conjugates were designed, synthesized and evaluated in vitro . The results of cytotoxicity assays illuminated that these conjugates had anti-tumor activity against B16, Hela and U87MG, and compound P3 exhibited excellent growth inhibition against U87MG cells. Interestingly, the cytotoxicity of these conjugates was significantly increased when combined with copper ions. Meanwhile, colony-formation assays, transwell migration assays, cell apoptosis assays and cell cycle distribution assays were performed to explore the anti-tumor mechanism of conjugates. Compound P3 and P4 exhibited good biological activity in above four experiments when combined with copper ions. Especially, P3 displayed better bioactivity compared to the other three compounds. These results indicated that conjugates might be metabolized in the cells to produce dithiocarbamates, then metabolites formed complexes with copper ions, generating anti-tumor effects. Furthermore, conjugates and their metabolized dithiocarbamate derivatives were investigated by molecular docking, the results exhibited that P3 had the strongest interaction with the proteins 6CCY and 5T92, which was consistent with the obtained results of cell experiments. Compound P3 might be a potential lead-compound for the treatment of breast cancer and glioma. Further research in vivo about these compounds would be performed in our following work.

Lactobacillus gallinarum modulates the gut microbiota and produces anti-cancer metabolites to protect against colorectal tumourigenesis

ObjectiveUsing faecal shotgun metagenomic sequencing, we identified the depletion of Lactobacillus gallinarum in patients with colorectal cancer (CRC). We aimed to determine the potential antitumourigenic role of L. gallinarum in colorectal tumourigenesis.DesignThe tumor-suppressive effect of L. gallinarum was assessed in murine models of CRC. CRC cell lines and organoids derived from patients with CRC were cultured with L. gallinarum or Escherichia coli MG1655 culture-supernatant to evaluate cell proliferation, apoptosis and cell cycle distribution. Gut microbiota was assessed by 16S ribosomal DNA sequencing. Antitumour molecule produced from L. gallinarum was identified by liquid chromatography mass spectrometry (LC-MS/MS) and targeted mass spectrometry.ResultsL. gallinarum significantly reduced intestinal tumour number and size compared with E. coli MG1655 and phosphate-buffered saline in both male and female murine intestinal tumourigenesis models. Faecal microbial profiling revealed enrichment of probiotics and depletion of pathogenic bacteria in L. gallinarum-treated mice. Culturing CRC cells with L. gallinarum culture-supernatant (5%, 10% and 20%) concentration-dependently suppressed cell proliferation and colony formation. L. gallinarum culture-supernatant significantly promoted apoptosis in CRC cells and patient-derived CRC organoids, but not in normal colon epithelial cells. Only L. gallinarum culture-supernatant with fraction size <3 kDa suppressed proliferation in CRC cells. Using LC-MS/MS, enrichments of indole-3-lactic acid (ILA) was identified in both L. gallinarum culture-supernatant and the gut of L. gallinarum-treated mice. ILA displayed anti-CRC growth in vitro and inhibited intestinal tumourigenesis in vivo.ConclusionL. gallinarum protects against intestinal tumourigenesis by producing protective metabolites that can promote apoptosis of CRC cells.

circHUWE1 Exerts an Oncogenic Role in Inducing DDP-Resistant NSCLC Progression Depending on the Regulation of miR-34a-5p/TNFAIP8

Background. Circular RNAs (circRNAs) are reported as competing endogenous RNAs (ceRNAs) and play key roles in non-small-cell lung cancer (NSCLC) progression. Thus, this study was aimed at clarifying underlying molecular mechanisms of circHUWE1 in NSCLC. Methods. The quantitative real-time polymerase chain reaction (RT-qPCR) and western blot analyses were used for examining circHUWE1, microRNA-34a-5p (miR-34a-5p), and tumor necrosis factor alpha-induced protein 8 (TNFAIP8). IC50 of cisplatin (DDP) in A549/DDP and H1299/DDP cells and cell viability were analyzed by the Cell Counting Kit 8 (CCK-8) assay. Colony forming assay was performed to assess colony forming ability. Cell apoptosis and cell cycle distribution were determined by flow cytometry. Migrated and invaded cell numbers were examined by transwell assay. The association among circHUWE1, miR-34a-5p, and TNFAIP8 was analyzed by dual-luciferase reporter and RNA immunoprecipitation assays. A xenograft experiment was applied to clarify the functional role of circHUWE1 in vivo. Results. circHUWE1 was upregulated in NSCLC tissues and cells, especially in DDP-resistant groups. circHUWE1 downregulation inhibited DDP resistance, proliferation, migration, and invasion while it induced apoptosis and cell cycle arrest of DDP-resistant NSCLC cells, which was overturned by silencing of miR-34a-5p. TNFAIP8 was a functional gene of miR-34a-5p, and the suppressive effects of miR-34a-5p overexpression on DDP-resistant NSCLC progression were dependent on the suppression of TNFAIP8. circHUWE1 inhibition also delayed tumor growth of DDP-resistant NSCLC cells. Conclusion. circHUWE1 functioned as a promoter in DDP-resistant NSCLC by interaction with miR-34a-5p-TNFAIP8 networks, providing novel insight into DDP-resistant NSCLC diagnosis and treatment.

DNA repair inhibitors sensitize cells differently to high and low LET radiation

The aim of this study was to investigate effects of high LET α-radiation in combination with inhibitors of DDR (DNA-PK and ATM) and to compare the effect with the radiosensitizing effect of low LET X-ray radiation. The various cell lines were irradiated with α-radiation and with X-ray. Clonogenic survival, the formation of micronuclei and cell cycle distribution were studied after combining of radiation with DDR inhibitors. The inhibitors sensitized different cancer cell lines to radiation. DNA-PKi affected survival rates in combination with α-radiation in selected cell lines. The sensitization enhancement ratios were in the range of 1.6–1.85 in cancer cells. ATMi sensitized H460 cells and significantly increased the micronucleus frequency for both radiation qualities. ATMi in combination with α-radiation reduced survival of HEK293. A significantly elicited cell cycle arrest in G2/M phase after co-treatment of ATMi with α-radiation and X-ray. The most prominent treatment effect was observed in the HEK293 by combining α-radiation and inhibitions. ATMi preferentially sensitized cancer cells and normal HEK293 cells to α-radiation. DNA-PKi and ATMi can sensitize cancer cells to X-ray, but the effectiveness was dependent on cancer cells itself. α-radiation reduced proliferation in primary fibroblast without G2/M arrest.

4SC-202 Exerts An Anti-tumor Effect in Cervical Cancer By Targeting PRLR Signaling Pathway

The aim of the present study is to investigate whether 4SC-202, a selective class I histone deacetylase inhibitor (HDACi), plays an anti-tumor role in cervical cancer (CC) by targeting prolactin receptor (PRLR). CCK-8 and colony formation assays were used to evaluate the effects of 4SC-202 on the proliferation of CC cells in vitro. Effects of 4SC-202 on the cell cycle distribution and apoptosis in SiHa cells were determined by flow cytometry and western blotting, respectively. Immunofluorescence and western blotting were performed to detect the activities of PRLR-related pathways and PRLR expression in CC cells. A xenograft tumor model in nude mice was established to examine effects of 4SC-202 on the tumor growth, apoptosis and PRLR-related pathways in vivo. The biochemical analyzer and H&E staining were used to detect the serum biochemical indexes and organ toxicity. 4SC-202 inhibited the proliferation of CC cells (SiHa, HeLa, and CaSki) in vitro in a time- and dose-dependent manner. SiHa cells were treated with 1 or 5 μM 4SC-202 for 72 h and then subjected to various functional assays. The assays showed that 4SC-202 significantly induced G2/M phase arrest and apoptosis, while inhibiting the activities of PRLR-related pathways and PRLR expression. In addition, 4SC-202 reduced tumor growth and induced apoptosis in vivo. 4SC-202 down-regulated the expression of PRLR and activities of PRLR-related pathways in the mouse model, displayed no effects on serum biochemical indicators and caused no toxicity to mouse organs. This finding suggests that 4SC-202 may serve as a novel therapeutic agent for CC.

Prothymosin α and Its C-Terminal Immunoreactive Decapeptide Show no Evidence of Acute Toxicity: A Preliminary in Silico, in Vitro and in Vivo Investigation

Background: Members of the α-thymosin family have long been studied for their immunostimulating properties. Among them, the danger-associated molecular patterns (DAMPs) prothymosin α (proTα) and its C-terminal decapeptide proTα(100–109) have been shown to act as immunomodulators in vitro, due to their ability to promote T helper type 1 (Th1) responses. Recently, we verified these findings in vivo, showing that both proTα and proTα(100-109) enhance antitumor-reactive T cell-mediated responses. Methods: In view of the eventual use of proTα and proTα(100-109) in humans, we investigated their safety profile in silico, in human leukocytes and cancer cells lines in vitro, and in immunocompetent mice in vivo, in comparison to the proTα derivative thymosin alpha 1 (Τα1), a 28-mer peptide extensively studied for its safety in clinical trials. Results: In silico prediction via computational tools showed that all three peptide sequences likely are non-toxic or do not induce allergic regions. In vitro, proTα, proTα(100-109) and Tα1 did not affect the viability of human cancer cell lines and healthy donor-derived leukocytes, did not promote apoptosis or alter cell cycle distribution. Furthermore, mice injected with proTα, proTα(100-109) and Tα1 at doses equivalent to the suggested dose regimen of Tα1 in humans, did not show signs of acute toxicity, whereas proTα and proTα(100-109) increased the levels of proinflammatory and Th1-type cytokines in their peripheral blood. Conclusion: Our preliminary findings suggest that proTα and proTα(100-109), even at high concentrations, are non-toxic in vitro and in an acute toxicity model in vivo; moreover, we show that the two peptides retain their immunomodulatory properties in vivo and, eventually, could be considered for therapeutic use in humans.

Expressing MLH1 in HCT116 cells increases cellular resistance to radiation by activating the PRKAC

Mut L homolog-1 (MLH1) is a key DNA mismatch repair protein which participates in the sensitivity to DNA damaging agents. However, its role in the radiosensitivity of tumor cells is less well characterized. In this study, we investigated the role of MLH1 in cellular responses to ionizing radiation (IR) and explored the signaling molecules involved. The isogenic pair of MLH1 proficient (MLH1+) and deficient (MLH1–) human colorectal cancer HCT116 cells was exposed to IR for 24 h at the dose of 3 cGy. The clonogenic survival was examined by the colony formation assay. Cell cycle distribution was analyzed with flow cytometry. Changes in the protein level of MLH1, DNA damage marker γH2AX, and protein kinase A catalytic subunit (PRKAC), a common target for anti-tumor drugs, were examined with Western blotting. The results showed that the HCT116 (MLH1+) cells demonstrated increased radio-resistance with increased S population, decreased G2 population, a low level of γH2AX, a reduced ratio of phosphorylated PRKACαβ to total PRKAC, and an elevated level of total PRKAC and phosphorylated PRKACβII following IR compared with the HCT116 (MLH1–) cells. Importantly, silencing PRKAC in HCT116 (MLH1+) cells increased the cellular radiosensitivity. In conclusion, MLH1 may increase cellular resistance to IR by activating PRKAC. Our finding is the first to demonstrate the important role of PRKAC in MLH1-mediated radiosensitivity, suggesting that PRKAC has potential as a biomarker and a therapeutic target for increasing radio-sensitization.

KRT17 Facilitates Proliferation, Migration and Invasion in Esophageal Squamous Cell Carcinoma by Regulating mTOR/S6K1 pathway

BackgroundEsophageal squamous cell carcinoma (ESCC) is one of the most aggressive malignancies worldwide which originates from the malignant transformation of esophageal epithelial cells. Dysregulated expression of Keratin17 (KRT17) has been claimed in a variety of malignancies, while its role in ESCC remains unclear. Therefore, our study aimed to explore the potential function and underlying molecular mechanism of KRT17 in ESCC.MethodsData-independent acquisition-mass spectrometry (DIA-MS) workflow was used to analysis KRT17 expression between ESCC and adjacent non-cancerous esophageal tissues. The online database gene expression profiling interactive analysis (GEPIA) was used to further determine the differential expression of KRT17 in tissues. The function of KRT17 in ESCC was tested on two human esophageal cancer cell lines (EC9706 and ECA109). Small interfering RNA (siRNA) was used to inhibit KRT17 expression. Cell proliferation was examined by cell counting kit 8 (CCK8) reagent, colony formation assay, cell cycle distribution analysis and apoptosis. Cell migration was examined by transwell and wound healing assay. Cell invasion was also examined by transwell assay. Western blot and quantitative real-time PCR (qRT-PCR) was used to evaluate protein and mRNA levels, respectively.ResultsKRT17 expression was higher in cancer tissues compared with normal tissues. Transfected with siKRT17 attenuated protein and mRNA levels of KRT17, inhibited proliferation, migration and invasion, and decreased mTOR/S6K1 phosphorylation levels in EC9706 and ECA109.ConclusionKRT17 facilitates proliferation, migration and invasion in ESCC cells, and these cell viability functions were mediated by mTOR/S6K1 pathway.

Dnmt3a is downregulated by Stat5a and mediates G0/G1 arrest by suppressing the miR-17-5p/Cdkn1a axis in Jak2V617F cells

Background Despite of the frequently reported Dnmt3a abormality in classical myeloproliferative neoplasms (cMPNs) patients, few research explores how the Dnmt3a is regulated by Jak2V617F mutation. In this study, we have investigated how the Dnmt3a is regulated by Jak2V617F mutation and its effects on downstream signaling pathways in cMPNs. Methods Specimens of Jak2V617F positive cMPN patients and normal controls were collected. Murine BaF3 cell line was used to construct cell models. Dual-Glo luciferase assays and chromatin immunoprecipitation (ChIP)-qPCR were performed to detect the impact of Stat5a on transcription activity of Dnmt3a. Soft agar colony formation assay and cell counting assay were performed to detect cell proliferation. BrdU staining and flow cytometry were used to investigate cell cycle distribution. Western blotting and quantitative reverse-transcription PCR (qPCR) were performed to detect the expression levels of genes. Results Firstly, the results of western blotting and qPCR revealed that compared with the control samples, Dnmt3a is downregulated in Jak2V617F positive samples. Then we explored the mechanism behind it and found that Dnmt3a is a downstream target of Stat5a, the transcription and translation of Dnmt3a is suppressed by the binding of aberrantly activated Stat5a with Dnmt3a promoter in Jak2V617F positive samples. We further revealed the region approximately 800 bp upstream of the first exon of the Dnmt3a promoter, which includes a gamma-activated sequence (GAS) motif of Stat5a, is the specific site that Stat5a binds to. Soft agar colony formation assay, cell counting assay, and BrdU staining and flow cytometry assay found that Dnmt3a in Jak2V617F-BaF3 cells significantly affected the cell proliferation capacity and cell cycle distribution by suppressing Cdkn1a via miR-17-5p/Cdkn1a axis and mediated G0/G1 arrest. Conclusions Transcription and translation of Dnmt3a is downregulated by the binding of Stat5a with Dnmt3a promoter in Jak2V617F cells. The GAS motif at promoter of Dnmt3a is the exact site where the Stat5a binds to. Dnmt3a conducted G0/G1 arrest through regulating miR-17-5p/Cdkn1a axis. The axis of Stat5a/Dnmt3a/miR-17-5p/Cdkn1a potentially provides a treatment target for cMPNs.