Digitoxin inhibits ICC cell properties via the NF­κB/ST6GAL1 signaling pathway.

Intrahepatic cholangiocarcinoma (ICC) is a type of liver cancer associated with poor prognosis and increased mortality; the limited treatment strategy highlights the urgent need for investigation. Traditional Chinese Medicine (TCM), used alone or in combination with other treatments, can enhance therapeutic efficacy, improve life quality of patients and extend overall survival. In total, two rounds of screening of a TCM library of 2,538 active compounds were conducted using a Cell Counting Kit­8 assay and ICC cell lines. Cell proliferation and migration abilities were assessed through colony formation, 5­ethynyl­2'­deoxyuridine, would healing and Transwell assays. The impact of digitoxin (DT) on signaling pathways was initially investigated using RNA sequencing and further validated using reverse transcription­quantitative PCR, western blotting, lectin blotting and flow cytometry. ICC cells stably overexpressing ST6 ß­galactoside α­2,6­sialyltransferase 1 (ST6GAL1) were generated through lentiviral transfection. It was shown that DT emerged as a highly effective anti­ICC candidate from two rounds high­throughput library screening. DT could inhibit the proliferation and migration of ICC cells by suppressing NF­κB activation and reducing nuclear phosphorylated­NF­κB levels, along with diminishing ST6GAL1 mRNA and protein expression. The aforementioned biological effects and signal pathways of DT could be counteracted by overexpressing ST6GAL1 in ICC cells. In conclusion, DT suppressed ICC cell proliferation and migration by targeting the NF­κB/ST6GAL1 signaling axis. The findings of the present study indicated the promising therapeutic effects of DT in managing ICC, offering new avenues for treatment strategies.

Serum N-glycomic profiling identifies candidate biomarker panels for assessing coronary artery stenosis severity.

Stenosis severity may escalate over the course of coronary artery disease (CAD), increasing the risk of death for the patient. Conventionally, the assessment of stenosis degree relies on invasive coronary angiography (ICA), an invasive examination unsuitable for patients in poor physical condition or those with contrast allergies and one that imposes a psychological burden on patients. Although abnormal serum N-glycan profiles have exhibited robust associations with various cardiovascular diseases, including CAD, their potential in diagnosing CAD stenosis remains to be determined. In this study, we performed a comprehensive analysis of serum N-glycome from 132 patients who underwent ICA and 27 healthy controls using MALDI-TOF-mass spectrometry. The patients who underwent ICA examination were categorized into four groups based on stenosis severity: no/mild/moderate/severe stenosis. Twenty-seven N-glycans were directly quantified, and 47 derived glycan traits were obtained. Notably, among these 74 glycan features, 18 exhibited variations across the study groups. Using a combination of least absolute shrinkage and selection operator and logistic regression analyses, we developed five diagnostic models for recognizing stenosis degree. Our results suggested that alterations in serum N-glycosylation modifications might be valuable for identifying stenosis degree and monitoring disease progression in individuals with CAD. It is expected to offer a noninvasive alternative for those who could not undergo ICA because of various reasons. However, the diagnostic potential of serum N-glycan panels as biomarkers requires multicenter, large cohort validation in the future.

Quercetin, a key active ingredient of Jianpi Zishen Xiehuo Formula, suppresses M1 macrophage polarization and platelet phagocytosis by inhibiting STAT3 activation based on network pharmacology.

Primary immune thrombocytopenia (ITP) is an autoimmune hemorrhagic disease, and abnormal M1 macrophage polarization participates in the pathogenesis of ITP. Jianpi Zishen Xiehuo (JZX) Formula has a good therapeutic effect on ITP. However, its key active ingredients and molecular mechanisms remain unclear. In this study, we explored the key active ingredients and potential targets of JZX in treating ITP using network pharmacology combined with in vitro experimental verification. A total of 157 active ingredients of JZX were identified from public databases, and quercetin was the most important one. One hundred sixty-five intersection targets of active ingredients in JZX, ITP, and macrophage polarization were obtained by Venn diagram. The top three potential targets were signal transducer and activator of transcription 3 (STAT3), protein kinase B (PKB/AKT) 1, and c-JUN through protein-protein interaction analysis. Molecular docking showed that quercetin had strong binding affinities with them all. In vitro experiment, CD16+ monocytes increased in ITP patients compared with healthy controls, which indicated a M1/M2 polarization imbalance in ITP. The expression levels of M1 polarization markers, CD86, CD80, and inducible nitric oxide synthase (iNOS), M1 polarization-associated cytokines, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6), and antibody-opsonized platelet phagocytosis significantly increased in THP-1 macrophages stimulated with lipopolysaccharide (LPS). Quercetin markedly inhibited the expressions of M1 markers, decreased the levels of TNF-α and IL-6, and down-regulated the phosphorylated STAT3 (p-STAT3) protein, which confirmed the prediction by network pharmacology and molecular docking. Importantly, quercetin significantly reduced the phagocytosis of antibody opsonised platelet. In conclusion, quercetin suppressed platelet phagocytosis in M1 macrophages via its anti-inflammatory effects and may serve as a potential drug for the treatment of ITP. Quercetin could be a key ingredient for JZX against ITP.

The mechanism of Qijing Mingmu decoction on cellular senescence of conjunctivochalasis.

BACKGROUND: Qijing Mingmu decoction (QJMM), a compound Chinese medicine preparation, which consists of Lycium barbarum, Polygonatum, Ophiopogon japonicus, Poria cocos, Glycyrrhiza, Eclipta prostrata and Ligusticum striatum, has been confirmed to be effective for the treatment of conjunctivochalasis (CCH) in clinic and reduce cellular senescence. However, the underlying mechanism is still unknown. Our previous study revealed that p38-mediated cellular senescence contributed to the pathogenesis of CCH. METHODS: To explore whether p38 might be the potential therapeutic target of QJMM for CCH, CCH fibroblasts were treated with QJMM granule and then the effect of QJMM granule on the expression and promoter activity of p38α was determined by western blot and dual luciferase reporter gene assay, respectively. Meanwhile, the influence of QJMM granule on cell proliferation, oxidative stress, cellular senescence and the expression of the cellular senescence-associated genes were measured by corresponding methods. RESULTS: QJMM granule significantly decreased the protein expression of p38α and p-p38α in CCH fibroblasts in a dose-dependent manner and inhibited p38α promoter activity. QJMM granule as well as the p38 inhibitor SB203580 reduced the level of reactive oxygen species and increased the activity of superoxide dismutase in CCH fibroblasts. QJMM granule and SB203580 promoted cell proliferation and reduced the percentage of SA-ß-Gal-positive cells. The mRNA and protein expression of p53 and p21 was remarkably down-regulated by QJMM granule as well as SB203580 and that of SMP30 was up-regulated in CCH fibroblasts. CONCLUSIONS: Our findings demonstrated that QJMM granule was effective for alleviating cellular senescence of CCH fibroblasts by p38 MAPK signaling and the followed p53/p21 signaling.

α­hederin overcomes hypoxia­mediated drug resistance in colorectal cancer by inhibiting the AKT/Bcl2 pathway.

Currently, chemoresistance is a major challenge that directly affects the prognosis of patients with colorectal cancer (CRC). In addition, hypoxia is associated with poor prognosis and therapeutic resistance in patients with cancer. Accumulating evidence has shown that α­hederin has significant antitumour effects and that α­hederin can inhibit hypoxia­mediated drug resistance in CRC; however, the underlying mechanism remains unclear. In the present study, viability and proliferation assays were used to evaluate the effect of α­hederin on the drug resistance of CRC cells under hypoxia. Sequencing analysis and apoptosis assays were used to determine the effect of α­hederin on apoptosis under hypoxia. Western blot analysis and reverse transcription­quantitative PCR were used to measure apoptosis­related protein and mRNA expression levels. Furthermore, different mouse models were established to study the effect of α­hederin on hypoxia­mediated CRC drug resistance in vivo. In the present study, the high expression of Bcl2 in hypoxic CRC cells was revealed to be a key factor in their drug resistance, whereas α­hederin inhibited the expression of Bcl2 by reducing AKT phosphorylation in vitro and in vivo, and promoted the apoptosis of CRC cells under hypoxia. By contrast, overexpression of AKT reversed the effect of α­hederin on CRC cell apoptosis under hypoxia. Taken together, these results suggested that α­hederin may overcome hypoxia­mediated drug resistance in CRC by inhibiting the AKT/Bcl2 pathway. In the future, α­hederin may be used as a novel adjuvant for reversing drug resistance in CRC.

Mechanism of Akt regulation of the expression of collagens and MMPs in conjunctivochalasis.

Akt is a central node of many signaling pathways, which plays important roles in cell survival, proliferation, migration, metabolism and collagen synthesis. Conjunctivochalasis (CCH) is one of the most common age-related ocular superficial diseases related to abnormalities in conjunctival extracellular matrix. Here, we studied the role of Akt regulating collagens and MMPs in the pathogenesis of CCH. Primary conjunctival fibroblasts were obtained from CCH patients (n = 13) and age-matched normal controls (n = 10). The levels of Akt, collagen type I, collagen type III, MMP1, and MMP3 were determined by Western blot, qRT-PCR, immunohistochemistry, and immunofluorescence staining. Normal control conjunctival fibroblasts were treated with Akt inhibitor A6730, and CCH fibroblasts were transfected with Akt overexpression vector. The expression of Akt in CCH was significantly lower than that in normal control of conjunctival tissues and cultured fibroblasts. Blocking Akt signaling with Akt inhibitor could inhibit the expression of collagen type I and collagen type III and upregulate the expression of MMP1 and MMP3. Meanwhile, compared with CCH fibroblasts transfected with control mimics, the protein and mRNA expression of collagen type I and collagen type III were increased significantly in Akt overexpression group, while the results of MMP1 and MMP3 in transfected fibroblasts were opposite. Taken together, Akt upregulated the expression of collagen type I and collagen type III and downregulated the expression of MMP1 and MMP3. Akt signaling pathway could provide a direct negative contribution to CCH and might be an attractive target for CCH therapy.

Design and Application of Metal Organic Framework ZIF-90-ZnO-MoS2 Nanohybrid for an Integrated Electrochemical Liquid Biopsy.

Limited healthcare capacity highlights the needs of integrated sensing systems for personalized health-monitoring. However, only limited sensors can be employed for point-of-care applications, emphasizing the lack of a generalizable sensing platform. Here, we report a metal organic framework (MOF) ZIF-90-ZnO-MoS2 nanohybrid-based integrated electrochemical liquid biopsy (ELB) platform capable of direct profiling cancer exosomes from blood. Using a bottom-up approach for sensor design, a series of critical sensing functions is considered and encoded into the MOF material interface by programming the material with different chemical and structural features. The MOF-based ELB platform is able to achieve one-step sensor fabrication, target isolation, nonfouling and high-sensitivity sensing, direct signal transduction, and multiplexed detection. We demonstrated the capability of the designed sensing system on differentiating cancerous groups from healthy controls by analyzing clinical samples from lung cancer patients, providing a generalizable sensing platform.

Bufalin exacerbates Photodynamic therapy of colorectal cancer by targeting SRC-3/HIF-1α pathway.

Photodynamic therapy (PDT) induces tumour cell death by producing reactive oxygen species (ROS), and hypoxia is one of the main factors that limits its efficiency. In our previous study, bufalin (BU) enhanced photosensitizer mTHPC-mediated PDT therapy in colorectal cancer (CRC) cells, but its mechanism was not elucidated. To explore a strategy for improving the efficacy of PDT, we designed iRGD-modified nanoparticles to co-capsuled mTHPC and BU for simultaneous delivery to the tumour site and explored the underlying mechanism of the synergistic anti-CRC effect. In our study, mTHPC&BU@VES-CSO/TPGS-RGD nanoparticles (T-B@NP) had a particle size of 148.3 ± 2.5 nm and a zeta potential of 22.8 ± 2.0 mV. Specifically, these nanoparticles passively accumulated in tumour cells, and under laser irradiation, mTHPC induced cell apoptosis and death. In addition, the sustained release of BU inhibited HIF-1α and reduced VEGF-mediated angiogenesis by targeting the SRC-3/HIF-1α pathway, which induced a strong PDT effect against CRC. In vivo studies demonstrated that codelivery of the nanoparticles under laser irradiation exhibited a superior antitumour effect (84.2%) and significantly prolonged survival time of mice, with the mechanisms of alleviating hypoxia and inhibiting angiogenesis. In summary, mTHPC and BU codelivery via nanoparticles efficiently enhances the therapeutic effects of PDT by inhibiting the SRC-3/HIF-1α pathway in CRC. This work provides an effective strategy to combat hypoxia-induced tumour resistance and overcome the barriers of PDT treatment.

Bufalin suppresses tumour microenvironment-mediated angiogenesis by inhibiting the STAT3 signalling pathway.

BACKGROUND: Antiangiogenic therapy has increasingly become an important strategy for the treatment of colorectal cancer. Recent studies have shown that the tumour microenvironment (TME) promotes tumour angiogenesis. Bufalin is an active antitumour compound whose efficacy has been indicated by previous studies. However, there are very few studies on the antiangiogenic effects of bufalin. METHODS: Herein, human umbilical vein endothelial cell (HUVEC) tube formation, migration and adhesion tests were used to assess angiogenesis in vitro. Western blotting and quantitative PCR were used to detect relevant protein levels and mRNA expression levels. A subcutaneous xenograft tumour model and a hepatic metastasis model were established in mice to investigate the influence of bufalin on angiogenesis mediated by the TME in vivo. RESULTS: We found that angiogenesis mediated by cells in the TME was significantly inhibited in the presence of bufalin. The results demonstrated that the proangiogenic genes in HUVECs, such as VEGF, PDGFA, E-selectin and P-selectin, were downregulated by bufalin and that this downregulation was mediated by inhibition of the STAT3 pathway. Overexpression of STAT3 reversed the inhibitory effects of bufalin on angiogenesis. Furthermore, there was little reduction in angiogenesis when bufalin directly acted on the cells in the tumour microenvironment. CONCLUSION: Our findings demonstrate that bufalin suppresses tumour microenvironment-mediated angiogenesis by inhibiting the STAT3 signalling pathway in vascular endothelial cells, revealing that bufalin may be used as a new antiangiogenic adjuvant therapy medicine to treat colorectal cancer.

Photodynamic therapy synergizes with PD-L1 checkpoint blockade for immunotherapy of CRC by multifunctional nanoparticles.

Checkpoint inhibitors, such as anti-PD-1/PD-L1 antibodies, have been shown to be extraordinarily effective, but their durable response rate remains low, especially in colorectal cancer (CRC). Recent studies have shown that photodynamic therapy (PDT) could effectively enhance PD-L1 blockade therapeutic effects, although the reason is still unclear. Here, we report the use of multifunctional nanoparticles (NPs) loaded with photosensitized mTHPC (mTHPC@VeC/T-RGD NPs)-mediated PDT treatment to potentiate the anti-tumor efficacy of PD-L1 blockade for CRC treatment and investigate the underlying mechanisms of PDT enhancing PD-L1 blockade therapeutic effect in this combination therapy. In this study, the mTHPC@VeC/T-RGD NPs under the 660-nm near infrared (NIR) laser could kill tumor cells by inducing apoptosis and/or necrosis and stimulating systemic immune response, which could be further promoted by the PD-L1 blockade to inhibit primary and distant tumor growth, as well as building long-term host immunological memory to prevent tumor recurrence. Furthermore, we detected that mTHPC@VeC/T-RGD NP-mediated PDT sensitizes tumors to PD-L1 blockade therapy mainly because PDT-mediated hypoxia could induce the hypoxia-inducible factor 1α (HIF-1α) signaling pathway that upregulates PD-L1 expression in CRC. Taken together, our work demonstrates that mTHPC@VeC/T-RGD NP-mediated PDT is a promising strategy that may potentiate the response rate of anti-PD-L1 checkpoint blockade immunotherapies in CRC.

Bufalin targets the SRC-3/MIF pathway in chemoresistant cells to regulate M2 macrophage polarization in colorectal cancer.

M2-polarized macrophages are one of critical factors in tumour chemoresistance. An increasing number of studies have shown that M2 macrophage polarization can be promoted by chemoresistance. A large number of evidences indicate that Bufalin has significant antitumour effect, previous studies have found that Bufalin can reduce the polarization of M2 macrophages to play an anti-tumour effect in vivo, but the mechanism remains unclear. In our study, we found that Bufalin reduced the polarization of M2 macrophages induced by chemoresistant cells both in vivo and in vitro; however, Bufalin had no obvious direct effect on M2 macrophage polarization. Furthermore, we demonstrated that Bufalin targeted the SRC-3 protein to reduce MIF release in chemoresistant cells in order to regulate the polarization of M2 macrophages. More interestingly, we also found that Cinobufacini, Bufalin is its main active monomer, which its could regulate the polarization of M2 macrophages to enhance the anti-tumour effect of oxaliplatin in vivo and in the clinic. Overall, this study provides a theoretical basis for the clinical application of drugs containing Bufalin as the main active ingredient in combination with established chemotherapy for the treatment of colorectal cancer.

Targeting CD133 reverses drug-resistance via the AKT/NF-κB/MDR1 pathway in colorectal cancer.

BACKGROUND: Recent studies have shown that multidrug resistance may be induced by the high stemness of cancer cells. Following prolonged chemotherapy, MDR protein 1 (MDR1) and CD133 increase in CRC, but the relationship between them is unclear. METHODS: The relationship between MDR and CSC properties in CRC was determined via CCK-8 assay, apoptosis assay, DOX uptake and retention, immunohistochemistry, immunofluorescence and flow cytometry. The correlations between their expression levels were evaluated using Spearman's rank statistical test and the Mann-Whitney test. Furthermore, the effect of CD133 on the repression of the AKT/NF-κB/MDR1 signalling pathway was investigated in vitro and in vivo. RESULTS: We found that CD133 increased with the emergence of drug-resistance phenotypes, and the high expression of MDR1/P-gp was consistently accompanied by positive expression of CD133 as demonstrated by the analysis of patient samples. Up- or downregulation of CD133 could regulate MDR via AKT/NF-κB/MDR1 signalling in CRC. A rescue experiment showed that the AKT/NF-κB signalling pathway is the main mechanism by which CD133 regulates MDR1/P-gp expression in CRC. CONCLUSIONS: Taken together, our results suggest that targeting CD133 reverses drug resistance via the AKT/NF-κB/MDR1 pathway and that this pathway might serve as a potential therapeutic target to reverse MDR in CRC.

ß-Sitosterol Reverses Multidrug Resistance via BCRP Suppression by Inhibiting the p53-MDM2 Interaction in Colorectal Cancer.

Phytosterols are widely present in vegetable oils, nuts, cereal products, fruits, and berries. Phytosterol-induced treatment sensitivity has recently shed light on alleviating multidrug resistance in cancer therapy. Here, we demonstrated that ß-sitosterol, the most common dietary phytosterol, recovers oxaliplatin (OXA) sensitivity in drug-resistant colorectal cancer (CRC) cells by inhibiting breast cancer resistance protein (BCRP) expression. We further showed evidence that ß-sitosterol could activate p53 by disrupting the p53-MDM2 interaction, leading to an increase in p53 translocation to the nucleus and silencing the nuclear factor-κB (NF-κB) pathway, which is necessary for BCRP expression. Finally, we suggested that the combination of OXA and ß-sitosterol has a synergistic tumor suppression effect in vivo using a xenograft mouse model. These results revealed that ß-sitosterol is able to mediate the p53/NF-κB/BCRP signaling axis to regulate the response of CRC to chemotherapy. The combined application of ß-sitosterol and OXA can be a potential way to improve CRC treatment.

Bufalin reverses multidrug resistance by regulating stemness through the CD133/nuclear factor-κB/MDR1 pathway in colorectal cancer.

Recent studies have shown that MDR could be induced by the high stemness of cancer cells. In a previous study, we found bufalin could reverse MDR and inhibit cancer cell stemness in colorectal cancer, but the relationship between them was unclear. Here we identified overexpressing CD133 increases levels of Akt/nuclear factor-κB signaling mediators and MDR1, while increasing cell chemoresistance. Furthermore, bufalin reverses colorectal cancer MDR by regulating cancer cell stemness through the CD133/nuclear factor-κB/MDR1 pathway in vitro and in vivo. Taken together, our results suggest that bufalin could be developed as a novel 2-pronged drug that targets CD133 and MDR1 to eradicate MDR cells and could ultimately be combined with conventional chemotherapeutic agents to improve treatment outcomes for patients with colorectal cancer.

The expression of MAPK signaling pathways in conjunctivochalasis.

This study investigated the potential role of MAPK signaling pathways in conjunctivochalasis (CCH). Twenty loose conjunctival biopsy samples from 20 CCH and 15 conjunctival biopsy samples from 15 normal controls (CON) were collected. The conjunctival fibroblasts were cultured in vitro. Immunofluorescence, ELISA, Western blot and reverse transcription-polymerase chain reaction (RT-PCR) were used. Our results showed that the expression of p-ERK, p-JNK, and p-p38 in CCH conjunctiva was significantly higher than that in CON group. The expression of p38 MAPK, JNK, and ERK proteins in CCH fibroblasts was significantly higher than that in CON group. The total expression of MAPK mRNA in CCH fibroblasts was significantly higher than that in CON group. The activated forms of p38 MAPK, JNK, and ERK proteins and mRNAs might up-regulate the expression of MMPs in CCH loose conjunctival tissue and fibroblasts, causing the degradation of collagen fibers and elastic fibers and promoting the occurrence of CCH. Our results deepen the understanding of CCH pathological mechanism.

P38-Mediated Cellular Senescence in Conjunctivochalasis Fibroblasts.

Purpose: Conjunctivochalasis (CCH) is a common ocular disease and has received extensive attention recently. However, its exact pathogenesis remains largely unknown. Owing to the high morbidity of CCH in older people, this study aimed to investigate whether cellular senescence contributes to CCH progression and the underlying mechanism. Methods: Loose conjunctival tissues from CCH patients (n = 13) and normal conjunctival tissues from age-matched persons (n = 12) were obtained and the fibroblasts were separately induced and obtained. Cellular senescence, and the expression of senescence-associated genes (p53 and p21) and p38 in CCH conjunctival tissues and normal controls, were determined by senescence-associated ß-galactosidase (SA-ß-Gal) staining and quantitative (q)RT-PCR, respectively. To explore the effects of p38 on cellular senescence in CCH fibroblasts, small interfering RNA (siRNA) targeting p38 (siP38) and p38-specific inhibitor SB203580 was performed in CCH fibroblasts. Then, cellular senescence, cell viability, reactive oxygen species (ROS) production, and gene expression were detected according to the corresponding methods. Results: CCH conjunctival tissues had significantly more senescent cells, evidenced by more SA-ß-Gal-positive cells, and higher expression of senescence-associated genes (p53 and p21) and p38. CCH fibroblasts transfected with siP38 or treated with SB203580 had obviously reduced numbers of senescent cells, decreased ROS production, and increased cell viability, as well as reduced expression of senescence-associated genes. Meanwhile, blocking p38 signaling decreased the expression of p53 and p21. Conclusions: Therefore, these findings indicate that cellular senescence might be a causative factor for CCH. P38 signaling might play an important role in the progress of cellular senescence in CCH fibroblasts via manipulation of p53/p21 signaling.

SnoN residue (1-366) attenuates hypertrophic scars through resistance to transforming growth factor-ß1-induced degradation.

Hypertrophic scars (HSs) are characterized by fibroblast hyperproliferation and excessive matrix deposition. During wound healing, transforming growth factor (TGF)-ß1/Smad signaling acts as a key regulator. As a transcriptional corepressor of TGF-ß1/Smads, SnoN is expressed at low levels in many fibrotic diseases due to TGF-ß1/Smad-induced degradation. SnoN residue (1-366; SR) is resistant to TGF-ß1-induced degradation. However, the expression and role of SR in HSs are unknown. Here, we inhibited TGF-ß1/Smad signaling via overexpression of SR to block fibroblast transdifferentiation, proliferation, and collagen deposition during HS formation. Our results showed that SnoN was downregulated in HS fibroblasts (HSFs) owing to TGF-ß1/Smad-induced degradation. Overexpression of SR in normal human dermal fibroblasts (NHDFs) and HSFs successfully blocked phosphorylation of Smad2 and Smad3, thereby inhibiting NHDF transdifferentiation and HSF proliferation and reducing type I collagen (ColI) and type III collagen (ColIII) production and secretion. In addition, we applied overexpressed full-length SnoN (SF) and SR to wound granulation tissue in a rabbit model of HSs. SR reduced wound scarring, improved collagen deposition and arrangement of scar tissue, and decreased mRNA and protein expression of ColI, ColIII, and α-smooth muscle actin (α-SMA) more effectively than SF in vivo. These results suggest that SR could be a promising therapy for the prevention of HS.

Hypoxia Induces Drug Resistance in Colorectal Cancer through the HIF-1α/miR-338-5p/IL-6 Feedback Loop.

Hypoxia is associated with poor prognosis and therapeutic resistance in cancer patients. Accumulating evidence has shown that microRNA (miRNA) plays an important role in the acquired drug resistance in colorectal carcinoma (CRC). However, the role of miRNA in hypoxia-induced CRC drug resistance remains to be elucidated. Here, we identified a hypoxia-triggered feedback loop that involves hypoxia-inducible transcription factor 1α (HIF-1α)-mediated repression of miR-338-5p and confers drug resistance in CRC. In this study, the unbiased miRNA array screening revealed that miR-338-5p is downregulated in both hypoxic CRC cell lines tested. Repression of miR-338-5p was required for hypoxia-induced CRC drug resistance. Furthermore, we identified interleukin-6 (IL-6), which mediates STAT3/Bcl2 activation under hypoxic conditions, as a direct miR-338-5p target. The resulting HIF-1α/miR-338-5p/IL-6 feedback loop was necessary for drug resistance in colon cancer cell lines. Using CRC patient samples, we found miR-338-5p has a negative correlation with HIF-1α and IL-6. Finally, in a xenograft model, overexpressing miR-338-5p in CRC cells and HIF-1α inhibitor PX-478 were able to enhance the sensitivity of CRC to oxaliplatin (OXA) via suppressing the HIF-1α/miR-338-5p/IL-6 feedback loop in vivo. Taken together, our results uncovered an HIF-1α/miR-338-5p/IL-6 feedback circuit that is critical in hypoxia-mediated drug resistance in CRC; targeting each member of this feedback loop could potentially reverse hypoxia-induced drug resistance in CRC.

Comparative transcriptome analysis of human conjunctiva between normal and conjunctivochalasis persons by RNA sequencing.

Conjunctivochalasis (CCH) is a common ocular disease, especially in aged people. However, the molecular mechanism of CCH on transcriptional level has been unclear. In this study, we characterized the transcriptional landscape of human conjunctiva and compared the transcriptome between normal persons (n = 10) and CCH patients (n = 11). Illumina RNA sequencing (RNA-seq) was performed to obtain transcriptional data, and these data were analyzed using various bioinformatics methods, including read mapping, the analysis of gene expression, gene ontology (GO) analysis and Kyoto Encyclopedia of Gene and Genomes (KEGG) metabolic pathway analysis. Additionally, expression patterns of 20 dysregupated genes were validated by qRT-PCR. RNA-seq result showed that clean ratios of 21 samples were more than 95% and more than 92% of all clean reads (32-41 million reads) were mapped to human genome sequence. There were 175 up-regulated genes and 582 down-regulated genes identified in CCH compared to normal persons. Among down-regulated genes in CCH, many genes were related with cell cycle and proliferation, such as BUB1, CCNB1, CCNB2 and CENPA, which might disturb cell growth and proliferation. In addition, several down-regulated genes were associated with keratinization and differentiation of epidermal cells, such as SPRR1A, SPRR1B, and CALML5. In over-expressed genes, CALML6 might play important roles on the development of CCH. The results of qRT-PCR confirmed the accuracy and credibility of RNA-Seq analysis. This study provided a lot of valuable information about pathogenic mechanism of CCH, which could be used to better study CCH in the future.

Association of 758 G/A polymorphism of 3'untranslated region of prohibitin with risk of gastric cancer.

BACKGROUND: A polymorphic variant allele (T-allele) in the 3'-UTR of prohibitin (C-to-T at nucleotide 729) was reported to be associated with an increased risk of breast cancer. However, the association between the 3'-UTR polymorphism of prohibitin and the susceptibility to gastric cancer remains unknown. Thus, we investigated the distribution of prohibitin genotypes in Chinese patients with gastric cancer and subsequently analyzed the association between the 3'-UTR polymorphism of prohibitin and the risk of gastric cancer in that population. METHODS: The distribution of 3'-UTR polymorphism of prohibitin in 82 gastric cancer patients was determined by sequencing and compared with that of 171 healthy controls. Luciferase reporter assay was used to investigate the effect of 3'-UTRs variant on PHB expression. RESULTS: Our study discovered two major polymorphic sites in the 3'-UTR of prohibitin (C-to-T at nucleotide 729 and G to A at nucleotide 758). The C/T polymorphism at 729 site was not associated with the increased risk of gastric cancer (P=.961, OR=1.044, 95%CI: 0.187-5.818); however, G/A polymorphism at nucleotide 758 increased the risk of gastric cancer (P=.017, OR=1.923, 95%CI: 1.119-3.305). Luciferase reporter constructs containing the 758A allele showed higher luciferase activity compared with the wild-type allele, which indicated that 758 G>A in 3'-UTR increased PHB expression. CONCLUSIONS: The G to A transition but not the C-to-T transition in the 3'-UTR of prohibitin was associated with an increased risk of gastric cancer in Chinese population.