Programmable Aptasensor for Regulating CRISPR/Cas12a Activity.

CRISPR-mediated aptasensors have gained prevalence for detecting non-nucleic acid targets. However, there is an urgent need to develop an easily customizable design to improve the signal-to-noise ratio, enhance universality, and expand the detection range. In this article, we report a CRISPR-mediated programmable aptasensor (CPAS) platform. The platform includes single-stranded DNA comprising the aptamer sequence, locker DNA, and a crRNA recognition region, forming a hairpin structure through complementary hybridization. With T4 DNA polymerase, the crRNA recognition region was transformed into a complete double-stranded DNA through stem-loop extension, thereby activating the trans-cleavage activity of Cas 12a and generating fluorescence signals. The specific binding between the target molecule and aptamer disrupted the formation of the hairpin structure, altering the fluorescence signals. Notably, the CPAS platform allows for easy customization by simply changing the aptamer sequence and locker DNA, without entailing adjustments to the crRNA. The optimal number of bases in the locker DNA was determined to be seven nucleotides for the SARS-CoV-2 spike (S) protein and four nucleotides for ATP. The CPAS platform exhibited high sensitivity for S protein and ATP detection. Integration with a lateral flow assay enabled sensitive detection within 1 h, revealing its excellent potential for portable analysis.

Effects of in vitro fermentation of Atractylodes chinensis (DC.) Koidz. polysaccharide on fecal microbiota and metabolites in patients with type 2 diabetes mellitus.

Atractylodes chinensis (DC.) Koidz. polysaccharide (AKP) has been shown to have hypoglycemic activity. In this study, the effects of AKP on fecal microbiota and metabolites in healthy subjects and patients with type 2 diabetes mellitus (T2DM) were investigated using an in vitro simulated digestive fermentation model. AKP were isolated and purified from Atractylodes chinensis (DC.) Koidz. Its main component AKP1 (AKP-0 M, about 78 % of AKP) has an average molecular weight of 3.25 kDa with monosaccharide composition of rhamnose, arabinose, and galactosamine in a molar ratio of 1: 1.25: 2.88. Notably, AKP fermentation might improve the intestinal microbiota of T2DM patients by the enrichment of some specific bacteria rather than the increase of microbial diversity. The addition of AKP specifically enriched Bifidobacteriaceae and weakened the proportion of Escherichia-Shigella. Moreover, AKP also increased the levels of short-chain fatty acids without affecting total gut gas production, suggesting that AKP could have beneficial effects while avoiding flatulence. Metabolomic analysis revealed that ARP fermentation caused changes in some metabolites, which were mainly related to energy metabolism and amino acid metabolism. Importantly, ARP fermentation significantly increased the level of myo-inositol, an insulin sensitizer. In addition, a significant correlation was observed between specific microbiota and differential metabolites. This study has laid a theoretical foundation for AKP application in functional foods.

Drug release and solubility properties of two zeolitic metal-organic frameworks influenced by their hydrophobicity/hydrophilicity.

Metal-organic frameworks (MOFs) have shown significant potential for drug delivery applications. However, there remains a scarcity of comprehensive research addressing the influence of surface properties of MOFs on drug release kinetics and drug solubility. This study focuses on examining the influence of MOFs hydrophilicity and hydrophobicity on the controlled release and solubility of drugs. To achieve this, we prepared drug-loaded nanoparticles through in situ synthesis and created a drug-MOF co-amorphous system using the ball milling technique. Under neutral conditions, the hydrophilic MOF-based drug delivery system demonstrated a comparatively slower drug release profile than its hydrophobic counterpart. This observation suggests that the hydrophilic system holds promise in mitigating drug side effects by enabling improved control over drug release. The implementation of hydrophobic MOFs in co-amorphous systems yields a more pronounced effect on enhancing solubility compared to hydrophilic MOFs. This study offers valuable insights for achieving optimal drug release kinetics and solubility by delicately manipulating surface properties of MOFs.

Ginsenoside Rg2 Promotes the Proliferation and Stemness Maintenance of Porcine Mesenchymal Stem Cells through Autophagy Induction.

Mesenchymal stem cells (MSCs) can be used as a cell source for cultivated meat production due to their adipose differentiation potential, but MSCs lose their stemness and undergo replicative senescence during expansion in vitro. Autophagy is an important mechanism for senescent cells to remove toxic substances. However, the role of autophagy in the replicative senescence of MSCs is controversial. Here, we evaluated the changes in autophagy in porcine MSCs (pMSCs) during long-term culture in vitro and identified a natural phytochemical, ginsenoside Rg2, that could stimulate pMSC proliferation. First, some typical senescence characteristics were observed in aged pMSCs, including decreased EdU-positive cells, increased senescence-associated beta-galactosidase activity, declined stemness-associated marker OCT4 expression, and enhanced P53 expression. Importantly, autophagic flux was impaired in aged pMSCs, suggesting deficient substrate clearance in aged pMSCs. Rg2 was found to promote the proliferation of pMSCs using MTT assay and EdU staining. In addition, Rg2 inhibited D-galactose-induced senescence and oxidative stress in pMSCs. Rg2 increased autophagic activity via the AMPK signaling pathway. Furthermore, long-term culture with Rg2 promoted the proliferation, inhibited the replicative senescence, and maintained the stemness of pMSCs. These results provide a potential strategy for porcine MSC expansion in vitro.

Mesenchymal stem cell suppresses the efficacy of CAR-T toward killing lymphoma cells by modulating the microenvironment through stanniocalcin-1.

Stem cells play critical roles both in the development of cancer and therapy resistance. Although mesenchymal stem cells (MSCs) can actively migrate to tumor sites, their impact on chimeric antigen receptor modified T cell (CAR-T) immunotherapy has been little addressed. Using an in vitro cell co-culture model including lymphoma cells and macrophages, here we report that CAR-T cell-mediated cytotoxicity was significantly inhibited in the presence of MSCs. MSCs caused an increase of CD4+ T cells and Treg cells but a decrease of CD8+ T cells. In addition, MSCs stimulated the expression of indoleamine 2,3-dioxygenase and programmed cell death-ligand 1 which contributes to the immune-suppressive function of tumors. Moreover, MSCs suppressed key components of the NLRP3 inflammasome by modulating mitochondrial reactive oxygen species release. Interestingly, all these suppressive events hindering CAR-T efficacy could be abrogated if the stanniocalcin-1 (STC1) gene, which encodes the glycoprotein hormone STC-1, was knockdown in MSC. Using xenograft mice, we confirmed that CAR-T function could also be inhibited by MSC in vivo, and STC1 played a critical role. These data revealed a novel function of MSC and STC-1 in suppressing CAR-T efficacy, which should be considered in cancer therapy and may also have potential applications in controlling the toxicity arising from the excessive immune response.

Immunotherapy is a type of cancer treatment that helps the immune system fight cancer. For example, chimeric antigen receptor T cell (CAR-T) therapy is used to target several types of blood cancer. It works by reprogramming patients' immune cells to target specific tumor cells. In blood cancers, CAR-T therapy works very well, but it can cause extreme responses from the patient's immune system, which can be life threatening. In solid tumors, CAR-T therapy is much less successful because the tumors secrete molecules into the space surrounding them, which weaken the immune processes that attack cancerous cells. Stem cells are the master cells of the body. Originating in the bone marrow, they can repair and regenerate the body's cells. Cancer stem cells play a role in resistance to CAR-T therapy, due ­ in part ­ to their ability to renew themselves, but the role of another type of stem cell, called mesenchymal stem cells, was less clear. Mesenchymal stem cells develop into tissues that line organs and blood vessels. Although it is known that mesenchymal stem cells are present in most cancers and play a role in shaping and influencing the space around tumors, their impact on CAR-T therapy has not been studied in depth. To find out more, Zhang et al. looked at the influence of a protein, called staniocalcin-1 (STC1), on CAR-T therapy, by studying cells grown in the laboratory and human tumor cells that had been implanted in mice. Zhang et al. found that mesenchymal stem cells reduce the ability of CAR-T therapy to destroy cancer cells and that they needed STC1 to do this successfully. They also increased the expression of molecules that dampen the immune system, and suppressed molecules called inflammasomes, which are an important part of the way the immune system detects disease. Moreover, reducing the amount of STC1 that mesenchymal stem cells expressed restored the effectivity of CAR-T therapy. This study increases our understanding of the way that mesenchymal stem cells affect CAR-T therapy. It has the potential to open up a new way of improving the efficiency of this treatment and of reducing the harmful side effects that it can cause.

Engineering CAR-NK cells targeting CD33 with concomitant extracellular secretion of anti-CD16 antibody revealed superior antitumor effects toward myeloid leukemia.

Acute myeloid leukemia (AML) is a common form of acute leukemia, and the currently available treatments are unsatisfactory. In the present study, we report an immune cell therapeutic strategy that employed genetically modified bifunctional CAR-NK cells. These cells combined the efficient targeting of AML cells by the CD33 molecule with the concomitant stimulation of NK cell-mediated cytotoxicity via the expression and extracellular secretion of anti-CD16 antibody (B16) that binds back to the FC receptor of NK cells. Compared to CAR-NK cells that target CD33 only, the bifunctional CD33/B16 CAR-NK cells showed superior killing efficiency toward AML cells in vitro. The increase in efficiency was approximately four-fold, as determined based on the number of cells needed to achieve 80% killing activity. An in vivo study using a xenograft model also revealed the effective clearance of leukemic cells and much longer survival, with no relapse or death for at least 60 days. In addition, the safety of CAR-NK cells did not change with additional expression of B16, as determined by the release of cytokines. These data revealed the development of a promising CAR-NK approach for the treatment of patients with AML, which may improve CAR-NK-based treatment strategy in general and may potentially be used to treat other tumors as well.

Lacticaseibacillus casei LH23 Suppressed HPV Gene Expression and Inhibited Cervical Cancer Cells.

Microbiota of lower female reproductive tract is special in its microorganism composition with Lactobacillus as the predominant bacteria. A few of Lactobacillus species have been identified to benefit the inhibition of inflammatory and malignant diseases. Lacticaseibacillus casei LH23 is a strain isolated from traditional fermented food and had been demonstrate to ameliorate DSS-induced colitis in mice. In the present study, effects of Lacticaseibacillus casei LH23 on cervical cancer cells were investigated. Supernatants of lysates and heat-inactivated Lacticaseibacillus casei LH23 were found to inhibit the expression of human papillomavirus genes E6/E7 which is the main causative factor of cervical cancer. With MTT, EdU staining, and TUNEL staining assays, Lacticaseibacillus casei LH23 was shown to suppress the proliferation and induced the apoptosis of cervical cancer cells. Additionally, with wound-healing and Western-blot assays, Lacticaseibacillus casei LH23 was shown to slowdown the migration of cervical cancer cells and altered the expression of metastasis-related genes. These results demonstrated the anti-cervical cancer potential of Lacticaseibacillus casei LH23.

Ameliorative Effect of Chitosan Oligosaccharides on Hepatic Encephalopathy by Reshaping Gut Microbiota and Gut-Liver Axis.

This study investigated the influence of chitosan oligosaccharides (COSs) on a thioacetamide-induced hepatic encephalopathy (HE) Wistar rat model. COS treatment statistically reduced the false neurotransmitters and blood ammonia in HE rats, along with the suppression of oxidative stress and inflammation. The disbalanced gut microbiota was detected in HE rats by 16S rDNA sequencing, but the abundance alterations of some intestinal bacteria at either the phylum or genus level were at least partly restored by COS treatment. According to metabolomics analysis of rat feces, six metabolism pathways with the greatest response to HE were screened, several of which were remarkably reversed by COS. The altered metabolites might serve as a bridge for the alleviated HE rats treated with COS and the enhanced intestinal bacterial structure. This study provides novel guidance to develop novel food or dietary supplements to improve HE diseases due to the potential beneficial effect of COS on gut-liver axis.

[The extracellular vesicles from gram-positive bacteria: a review].

Extracellular vesicles (EVs), also known as membrane vesicles, are vesicular bodies secreted by eukaryotic cells and bacteria. EVs can carry proteins, DNA, RNA, and various metabolites for the exchange and transmission of substances between cells. They play contents-dependent physiological functions, such as delivering nutrients, participating in immune response, and treating cancers. Currently, most studies focus on the exploration of vesicles secreted by eukaryotic cells and gram-negative bacteria, while few studies focus on gram-positive bacteria. This review summarized the production, content composition, physiological function, and engineering of EVs secreted by gram-positive bacteria, and prospected future perspectives in this area.

Myocardin/microRNA-30a/Beclin1 signaling controls the phenotypic modulation of vascular smooth muscle cells by regulating autophagy.

Upon vascular injury, vascular smooth muscle cells (VSMCs) change from a contractile phenotype to a synthetic phenotype, thereby leading to atherogenesis and arterial restenosis. Myocardin (MYOCD) is essential for maintaining the contractile phenotype of VSMCs. Deletion of MYOCD in VSMCs triggers autophagy. However, the molecular mechanism underlying the effect of MYOCD on autophagy is not clear. In this study, knockdown of MYOCD in human aortic VSMCs (HA-VSMCs) triggered autophagy and diminished the expression of SMC contractile proteins. Inhibition of autophagy in MYOCD-knockdown cells restored the expression of contractile proteins. MYOCD activated the transcription of miR-30a by binding to the CArG box present in its promoter, as confirmed by luciferase reporter and chromatin immune coprecipitation assays, while miR-30a decreased the expression of autophagy protein-6 (ATG6, also known as beclin1) by targeting its 3'UTR. Restoring the expression of miR-30a in MYOCD-knockdown cells upregulated the levels of contractile proteins. Treatment of VSMCs with platelet-derived growth factor type BB (PDGF-BB) resulted in the transformation of VSMCs to a proliferative phenotype. A low level of miR-30a was observed in PDGF-BB-treated HA-VSMCs, and re-expression of miR-30a led to a decrease in proliferative marker expression. Furthermore, using a wire injury mouse model, we found that miR-30a expression was significantly downregulated in the arterial tissues of mice and that restoration of miR-30a expression at the injured site abolished neointimal formation. Herein, MYOCD could inhibit autophagy by activating the transcription of miR-30a and that miR-30a-mediated autophagy defects could inhibit intimal hyperplasia in a carotid arterial injury model.

Experimental Study of the Thermal Decomposition Properties of Binary Imidazole Ionic Liquid Mixtures.

Ionic liquids (ILs) have a wide range of applications, owing to their negligible vapor pressure, high electrical conductivity, and low melting point. However, the thermal hazards of ILs and their mixtures are also non-negligible. In this study, the thermal hazards of various binary imidazolium ionic liquids (BIIL) mixtures were investigated. The effects of parent salt components and molar ratios on the thermal decomposition temperature (Td) and flashpoint temperature (Tf) are investigated. It is found that both Td and Tf increase as the proportion of highly thermally stable components in BIIL mixtures increases. Furthermore, the decomposition process of BIIL mixtures can be divided into two stages. For most molar ratios, the Tf of the BIIL mixtures is in the first stage of thermal decomposition. When the proportion of highly thermally stable components is relatively high, Tf is in the second stage of thermal decomposition. The flammability is attributed to the produced combustible gases during the thermal decomposition process. This work would be reasonably expected to provide some guidance for the safety design and application of IL mixtures for engineering.

ERa-36 instead of ERa mediates the stimulatory effects of estrogen on the expression of viral oncogenes HPV E6/E7 and the malignant phenotypes in cervical cancer cells.

High risk human papillomavirus (HPV) is the main causative factor of cervical cancer. In addition, estrogen and its receptors are also involved in the development of carcinogenesis. The canonical estrogen receptor ERα is frequently deficient while its variant ERα-36 is highly expressed in cervical cancer cells. The biological significance for this receptor transition from ERα to ERα-36 remains unclear. In the present study, the results of RT-PCR and Western blot demonstrated that ERα and ERα-36 function antagonistically on the expression of the viral oncogenes HPV E6 and E7. At mRNA and protein levels, ERα inhibited HPV E6/E7 expression whereas ERα-36 stimulated HPV E6/E7 expression. Overexpression of ERα-36 promoted cell proliferation while reintroduction of ERα into cervical cancer cells did not significantly affect cell proliferation which is in line with the different effects of . ERα-36 and ERα on the expression of cell cycle regulator, namely p53, p21 and cyclin D1. Furthermore, ERα suppressed whereas ERα-36 promoted the migration and invasion of cervical cancer cells, which should be related to the oppositive roles of ERα and ERα-36 in the Wnt/ß-catenin/MRTF-A signaling pathway which is activated by HPV E7. Results of this study suggest that ERα functions as a tumor suppressor whereas ERα-36 is an oncoprotein in cervical cancer cells. ERα deficiency together with ERα-36 overexpression might enhance the expression of HPV E6/E7 genes and facilitate the development of cervical cancer. Targeting ERα-36 with selective antagonists should be a promising strategy for cervical cancer therapy.

Predicting Thermal Decomposition Temperature of Binary Imidazolium Ionic Liquid Mixtures from Molecular Structures.

Ionic liquids (ILs) have been regarded as "designer solvents" because of their satisfactory physicochemical properties. The 5% onset decomposition temperature (T d,5%onset) is one of the most conservative but reliable indicators for characterizing the possible fire hazard of engineered ILs. This study is devoted to develop a quantitative structure-property relationship model for predicting the T d,5%onset of binary imidazolium IL mixtures. Both in silico design and data analysis descriptors and norm index were employed to encode the structural characteristics of binary IL mixtures. The subset of optimal descriptors was screened by combining the genetic algorithm with the multiple linear regression method. The resulting optimal prediction model was a four-variable multiple linear equation, with the average absolute error (AAE) for the external test set being 12.673 K. The results of rigorous model validations also demonstrated satisfactory model robustness and predictivity. The present study would provide a new reliable approach for predicting the thermal stability of binary IL mixtures.

Synthesis of Uniform Gold Nanorods with Large Width to Realize Ultralow SERS Detection.

In this work, we successfully demonstrate high-yield synthesis of high-quality gold nanorods (Au NRs) with width ranging from 6.5 nm to 175 nm by introducing heptanol molecules as secondary templating agents during cetyltrimethylammonium bromide-templated, seeded growth method. The results show that an appropriate concentration of heptanol molecules not only alter the micellization behavior of CTAB in water, but also help silver ions impact the symmetry-breaking efficiency of additional Au-NP seeds in addition to enhancing the utilization of gold precursors. Moreover, the generality and versatility of the present strategy for synthesis of Au NRs with flexible controlled dimensions are further demonstrated by successful synthesis of Au NRs with the assistance of other fatty alcohols with properly long alkyl chains. Furthermore, when arrays of vertically aligned Au NRs with large width (AVA-Au120×90 NRs) are used as SERS substrates, they can achieve the ultralow limit of detection for crystal violet (10-16  M) with good reliability and reproducibility, and the rapid detection and identification of residual harmful substances.

Estrogen enhances the cytotoxicity of PARP inhibitors on breast cancer cells through stimulating nitric oxide production.

Inhibition of Poly(ADP-ribose) polymerase (PARP) is effective for breast cancer susceptibility genes 1 (BRCA1)-deficient breast cancers. Although hormones play critical roles on the occurrence as well as being used in conventional therapies of breast cancer, their impacts on PARP-targeted therapy have been poorly addressed. Here, we showed that addition of estrogen could enhance the cytotoxicity of PARP inhibitors on estrogen receptor (ER)-positive breast cancer cells, causing significant suppression of cell growth. Further analysis revealed that the impact was due to estrogen's stimulating the production of nitric oxide (NO), which could be abrogated when blocking NO formation. Moreover, the effect of estrogen can be resembled by two exogenous nitric oxide donors (SNAP and GSNO). Using ER-negative cell line MDA-MB231, estrogen could not enhance the cell killing of PARP inhibitors any more, but addition of NO donors re-established the enhancing effects. The increased NO level led to accumulation of DNA double strand breaks (DSBs) based on the formation of H2AX foci. Consistent with earlier studies, we demonstrated that NO suppressed the expression of BRCA1, a key player involved in DSB recombination repair. Taken together, these data reveal an important role of estrogen on the treatment of PARP inhibitors, which may affect its clinical treatment and should be considered in precision therapies for ER-positive and negative cancers.

DNMT3A inhibits E2F1-induced arterial marker expression and impairs angiogenesis in human umbilical artery endothelial cells.

Arterial marker genes EphrinB2 and HEY2 are essential for cardiovascular development and postnatal neovascularization. Our previous study confirmed that E2F1 could activate the transcription of EphrinB2 and HEY2 in human mesenchymal stem cells; however, the detailed mechanism has not been resolved yet. In this study, we focused on the interaction between E2F1 and DNMT3A, a de novo DNA methyltransferase, on regulating the expression of EphrinB2 and HEY2, and explored the potential mechanisms. Gain- and loss-of-function experiments implicated the positive effect of E2F1 on the expression of EphrinB2 and HEY2 and tube formation in human umbilical artery endothelial cells. Accumulation of DNMT3A decreased the levels of EphrinB2 and HEY2, and impaired tube formation induced by E2F1, while inhibiting DNMT3A by RNA interference augmented their expression and angiogenesis in E2F1-trasfected cells. We then asked whether the low expressions of EphrinB2 and HEY2 induced by DNMT3A are related to the methylation status of their promoters. Surprisingly, the methylation status of the CpG islands in the promoter region was not significantly affected by overexpression of exogenous DNMT3A. Furthermore, the interaction between E2F1 and DNMT3A was confirmed by co-immunoprecipitation. DNMT3A could inhibit the transcription of EphrinB2 and HEY2 promoters by affecting the binding of E2F1 to its recognition sequences as revealed by luciferase reporter assay and chromatin immunoprecipitation. These results identified a novel mechanism underlying the cooperation of DNMT3A with E2F1 on regulating target gene expression, and revealed their roles in the angiogenic process.

Synthesis of large gold nanoparticles with deformation twinnings by one-step seeded growth with Cu(ii)-mediated Ostwald ripening for determining nitrile and isonitrile groups.

In this work, uniform and large gold nanoparticles (Au NPs) including quasi-spherical (QS) Au NPs with average diameters of 70 to 196 nm and trisoctahedral (TOH) Au NPs with average diameters of 140 to 195 nm were successfully synthesized by controlling the concentration of Cu2+ ions and the particle number of 3 nm Au-NP seeds, respectively, using a one-step seeded growth method with Cu2+-mediated Ostwald ripening. It is found that because of the concentration-dependent under-potential deposition of Cu2+ ions (CuUPD), 3 nm Au-NP seeds are firstly changed into Au NPs with a controlled QS- or TOH shape at the initial growth stage, followed by the conformal growth of Au atoms onto the initially formed Au NPs due to Cu2+-mediated Ostwald ripening, in which the extra Au atoms come from the dissolution of in situ Au nuclei by the unavoidable self-nucleation. Moreover, the as-prepared QS Au NPs with a rough surface exhibit a better SERS performance for physically adsorbed probes (crystal violet, CV) than the TOH Au NPs with sharp tips and with a comparable size. Furthermore, the as-prepared QS Au NPs can be used to distinguish nitrile and isonitrile groups by surface-enhanced Raman scattering (SERS) due to the presence of deformation twinnings. Thus, the as-prepared QS Au NPs with a rough surface and deformation twinnings can be further used as templates for the fabrication of bimetallic materials with multi-functionalities.

Tip60 and p300 function antagonistically in the epigenetic regulation of HPV18 E6/E7 genes in cervical cancer HeLa cells.

BACKGROUND: High-risk HPV is a causative factor of cervical cancer. HPV DNA fragments integrate into host genome resulting in the constitutive expression of HPV genes E6 and E7 under the regulation of transcription factors, such as p300 and Tip60. Interestingly, Tip60, a factor with HAT (histone acetyl transferase) activity, represses HPV18 E6/E7 genes while another HAT p300 activates the transcription of HPV18 E6/E7. OBJECTIVE: To explore the mechanism for the opposite roles of Tip60 and p300 in the virus gene regulation, and the influence of Tip60 and p300 in histone modifications in the regulatory sequence of HPV18 genes. METHODS: Tip60 or p300 was either knocked down or overexpressed in HeLa cells. The effects on HPV E6E7 expression were determined with RT-qPCR. The association of RNA polymerase II and the enrichment of acetylated or methylated histones in HPV promoter region were measured by ChIP assays with specific antibodies. RESULTS: ChIP results showed that Tip60 and p300 differently affected the modifications of histone H3K9 and the deposition of nucleosomes in HPV18 long control region (LCR). HPV18 LCR in HeLa cells is bivalent chromatin carrying both the active histone H3K9 acetylation mark and the repressive histone H3K9 trimethylation mark, the balance is maintained by Tip60 and p300. CONCLUSION(S): Based on the roles of Tip60 and p300 in HPV gene regulation, chemical compounds targeting Tip60 or p300 are potential anti-cervical cancer drugs.

SET and MYND domain-containing protein 3 inhibits tumor cell sensitivity to cisplatin.

Cisplatin resistance has been a major factor limiting its clinical use as a chemotherapy drug. The present study aimed to investigate whether SET and MYND domain-containing protein 3 (SMYD3), a histone methyltransferase closely associated with tumors can affect the sensitivity of tumors to cisplatin chemotherapy. Real time-qPCR, western blotting, the luciferase reporter, MTT and clonogenic assays were performed to detect the effects of SMYD3 on the chemotherapy capacity of cisplatin. In the present study, SMYD3 exhibited different expression patterns in MCF-7 and T47D breast cancer cells. In addition, this differential expression was associated with tumor cell resistance to cisplatin. Furthermore, SMYD3 knockdown following small interfering RNA transfection increased cisplatin sensitivity, whereas SMYD3 overexpression decreased cisplatin sensitivity. In addition, SMYD3 knockdown synergistically enhanced cisplatin-induced cell apoptosis. SMYD3 expression was downregulated during cisplatin treatment. In addition, transcriptional regulatory activities of SMYD3 3'-untranslated region were also downregulated. These results suggested that SMYD3 may affect cell sensitivity to cisplatin and participate in the development of cisplatin resistance, which is a process that may involve microRNA-124-mediated regulation.