Cytotoxic jatrophane diterpenoids from the aerial parts of Euphorbia helioscopia.

A phytochemical study of 80% ethanol extract from the aerial parts of Euphorbia helioscopia led to the isolation of three new jatrophane diterpenoids, euphoheliphanes A-C (1-3). Their structures were established on the basis of spectroscopic data (NMR, IR, UV, and MS). The isolated diterpenoids were tested in vitro for cytotoxic potentials against 6 renal cancer cell lines. As a result, compounds 1-3 exhibited some cytotoxic activities against all the tested tumor cell lines with IC50 values less than 50 µM.[Formula: see text].

[Stem cells for the treatment of Peyronie's disease].

Peyronie's disease (PD) is a connective tissue disorder characterized as fibrotic plaque localized in the tunica albuginea (TA), and its pathomechanism remains obscure. Endeavors are being made to explore effective and minimally invasive therapeutic strategies for PD, and some experimental studies have verified the preventative and therapeutic effects of stem cells (SC), especially adipose tissue-derived SCs (ADSC), on this disease and excavated some of their action mechanisms. Some scholars attempted the integration of SCs with graft tissues, aiming at the improvement of TA grafting and reconstruction. The only publicly available clinical trial of SC therapy for PD was encouraging, and further on-coming relevant researches are expected with simultaneous optimization of the scheme. In a word, the application of SCs in the prevention and treatment of PD is a promising topic for clinical research, and there remain quite a lot of unknowns to be explored. This article summarizes the existing researches in this field.

Applications and research advance of genome shuffling for industrial microbial strains improvement.

Genome shuffling, an efficient and practical strain improvement technology via recursive protoplasts fusion, can break through the limits of species even genus to accelerate the directed evolution of microbial strains, without requiring the comprehensively cognized genetic background and operable genetic system. Hence this technology has been widely used for many important strains to obtain the desirable industrial phenotypes. In this review, we introduce the procedure of genome shuffling, discuss the new aid strategies of genome shuffling, summarize the applications of genome shuffling for increasing metabolite yield, improving strain tolerance, enhancing substrate utilization, and put forward the outlook to the future development of this technology.

[Predictive factors for clinically significant elevation of post-prostatectomy Gleason score in patients with biopsy Gleason score ≤7].

OBJECTIVE: To investigate the prognostic factors for clinically significant increase in post-prostatectomy Gleason score (pGS) in patients with biopsy Gleason score (bGS) ≤7. METHODS: This retrospective study included 170 cases of prostate cancer treated by radical prostatectomy in our hospital from January 2010 to December 2017. We analyzed the clinical and pathological data on the patients, including the age, preoperative serum tPSA, fPSA, fPSA / tPSA, prostate volume, PSA density (PSAD), and positive puncture rate of the patients with clinically significant elevation of pGS, as well as the possible factors for clinically significant pGS increase in patients with bGS = 7 and those with bGS ≤ 6. RESULTS: The pGS was found consistent with the bGS in 95 (55.9%) of the 170 patients, decreased in 11 (6.5%) and increased in 64 (37.6%). Among those with elevated pGS, 55 (32.4%) were shown with and the other 9 (5.3%) without clinical significance. Clinically significant escalation of pGS was markedly correlated with the positive puncture rate in the patients with bGS = 7 (P = 0.021) and with the age (P = 0.018) and PSAD (P = 0.033) of those with bGS ≤ 6. ROC curve analysis further showed the positive puncture rate > 0.528 in the patients with bGS = 7 and a higher risk of clinically significant pGS increase in those aged > 64.5 years with bGS ≤ 6 and PSAD > 0.267 µg/(L·g). CONCLUSIONS: Clinically significant elevation of pGS is correlated with the rate of positive punctures in prostate cancer patients with bGS = 7 and with age and PSAD in those with bGS ≤ 6.

Upregulated P2X3 Receptor Expression in Patients with Intractable Temporal Lobe Epilepsy and in a Rat Model of Epilepsy.

Purinergic P2X3 receptors (P2X3Rs) play extensive roles in nerve cells in the central nervous system, particularly in hyperexcitability and calcium (Ca(2+)) influx. However, the role of P2X3Rs in epilepsy has not been previously investigated. To determine the relationship between P2X3Rs and epilepsy, the expression and cellular location of P2X3Rs in patients with intractable temporal lobe epilepsy (TLE) and in a lithium chloride-pilocarpine-induced chronic rat model of epilepsy were assessed. Furthermore, the function of P2X3Rs was assessed in vitro. Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were used to evaluate the expression levels of P2X3Rs in brain tissues from TLE patients and an epileptic rat model, whereas immunofluorescence labeling was applied to determine the distribution of target proteins. Whole-cell recording was subsequently performed to identify the influence of P2X3Rs on seizure-like discharges. P2X3Rs were located at the cell bodies and dendrites of neurons with significantly increased expression in the TLE patients and epileptic rat model. In vitro, P2X3R activation accelerated sustained repetitive firing, whereas P2X3R inhibition led to relatively low-frequency discharges. To the best of our knowledge, this is the first study provide evidence that upregulated P2X3R expression exists in both epileptic humans and rats and may aggravate the epileptic state in vitro. Thus, P2X3Rs may represent a novel therapeutic target for antiepileptic drugs.

Genetically engineered nanomodulators elicit potent immunity against cancer stem cells by checkpoint blockade and hypoxia relief.

Rapid development of checkpoint inhibitors has provided significant breakthroughs for cancer stem cell (CSC) therapy, while the therapeutic efficacy is restricted by hypoxia-mediated tumor immune evasion, especially hypoxia-induced CD47 overexpression in CSCs. Herein, we developed a genetically engineered CSC membrane-coated hollow manganese dioxide (hMnO2@gCMs) to elicit robust antitumor immunity by blocking CD47 and alleviating hypoxia to ultimately achieve the eradication of CSCs. The hMnO2 core effectively alleviated tumor hypoxia by inducing decomposition of tumor endogenous H2O2, thus suppressing the CSCs and reducing the expression of CD47. Cooperating with hypoxia relief-induced downregulation of CD47, the overexpressed SIRPα on gCM shell efficiently blocked the CD47-SIRPα "don't eat me" pathway, synergistically eliciting robust antitumor-mediated immune responses. In a B16F10-CSC bearing melanoma mouse model, the hMnO2@gCMs showed an enhanced therapeutic effect in eradicating CSCs and inhibiting tumor growth. Our work presents a simple, safe, and robust platform for CSC eradication and cancer immunotherapy.

Microwave-responsive gadolinium metal-organic frameworks nanosystem for MRI-guided cancer thermotherapy and synergistic immunotherapy.

The clinical application of cancer immunotherapy is unsatisfied due to low response rates and systemic immune-related adverse events. Microwave hyperthermia can be used as a synergistic immunotherapy to amplify the antitumor effect. Herein, we designed a Gd-based metal-organic framework (Gd-MOF) nanosystem for MRI-guided thermotherapy and synergistic immunotherapy, which featured high performance in drug loading and tumor tissue penetration. The PD-1 inhibitor (aPD-1) was initially loaded in the porous Gd-MOF (Gd/M) nanosystem. Then, the phase change material (PCM) and the cancer cell membrane were further sequentially modified on the surface of Gd/MP to obtain Gd-MOF@aPD-1@CM (Gd/MPC). When entering the tumor microenvironment (TME), Gd/MPC induces immunogenic death of tumor cells through microwave thermal responsiveness, improves tumor suppressive immune microenvironment and further enhances anti-tumor ability of T cells by releasing aPD-1. Meanwhile, Gd/MPC can be used for contrast-enhanced MRI. Transcriptomics data revealed that the downregulation of MSK2 in cancer cells leads to the downregulation of c-fos and c-jun, and ultimately leads to the apoptosis of cancer cells after treatment. In general, Gd/MPC nanosystem not only solves the problem of system side effect, but also achieves the controlled drug release via PCM, providing a promising theranostic nanoplatform for development of cancer combination immunotherapy.

Lymph node targeting strategy using a hydrogel sustained-release system to load effector memory T cells improves the anti-tumor efficacy of anti-PD-1.

Communication between tumors and lymph nodes carries substantial significance for antitumor immunotherapy. Remodeling the immune microenvironment of tumor-draining lymph nodes (TdLN) plays a key role in enhancing the anti-tumor ability of immunotherapy. In this study, we constructed a biomimetic artificial lymph node structure composed of F127 hydrogel loading effector memory T (TEM) cells and PD-1 inhibitors (aPD-1). The biomimetic lymph nodes facilitate the delivery of TEM cells and aPD-1 to the TdLN and the tumor immune microenvironment, thus realizing effective and sustained anti-tumor immunotherapy. Exploiting their unique gel-forming and degradation properties, the cold tumors were speedily transformed into hot tumors via TEM cell supplementation. Meanwhile, the efficacy of aPD-1 was markedly elevated compared with conventional drug delivery methods. Our finding suggested that the development of F127@TEM@aPD-1 holds promising potential as a future novel clinical drug delivery technique. STATEMENT OF SIGNIFICANCE: F127@TEM@aPD-1 show unique advantages in cancer treatment. When injected subcutaneously, F127@TEM@aPD-1 can continuously supplement TEM cells and aPD-1 to tumor draining lymph nodes (TdLN) and the tumor microenvironment, not only improving the efficacy of ICB therapy through slow release, but also exhibiting dual regulatory effects on the tumor and TdLN.

Novel Mutation of Hydroxymethylbilane Synthase in a Case of Acute Intermittent Porphyria Presenting with Posterior Reversible Encephalopathy Syndrome.

Acute intermittent porphyria (AIP) is an autosomal, dominant, hereditary metabolic disease caused by an inherited deficiency of hydroxymethylbilane synthase (HMBS), a crucial enzyme in the heme biosynthetic pathway. It can affect the central, peripheral, and autonomic nervous systems. We report a 23-year Chinese woman who presented with severe abdominal pain, convulsions, constipation, tachycardia, quadriparesis, and hyponatremia, accompanied by posterior reversible encephalopathy syndrome (PRES). The clinical diagnosis of AIP was made after positive urine Watson-Schwartz test for porphobilinogen (PBG). Genetic testing is important for AIP patients in confirming the diagnosis. We identified a new insertion mutation in intron 14 [c.1005dupC (p.I336Hfs*23)] of the HMBS in her genomic DNA. Timely and accurate treatment of AIP may improve disease prognosis. Key Words: Acute intermittent porphyria, Mutation, Posterior reversible encephalopathy syndrome.

Temperature controllable electrochemical sensors based on horseradish peroxidase as electrocatalyst at heated Au disk electrode and its preliminary application for H2O2 detection.

In this paper, horseradish peroxidase (HRP) was successfully immobilized on heated Au disk electrode (HAuDE) by biotin-streptavidin specific interaction through HS-ssDNA-biotin self-assembled on HAuDE for investigation the electrocatalytic activity of HRP. With elevated electrode temperature, the significant temperature effect of the electrocatalytic activity of HRP for H2O2 reduction was demonstrated by using this bio-sensing platform. With an electrode temperature of 40 °C, a detection limit of 1.5 × 10-6 mol L-1 for H2O2 reduction could be obtained, which was more than one magnitude lower than that with an electrode temperature of 0 °C. Because HRP can be widely used as an enzyme label for amplification detection, this sensing platform can be broadly applied to analytical chemistry such as nucleic acid detection, and aptamer-based biosensors.

Estrogen effects on fetal penile and urethral development in organotypic mouse genital tubercle culture.

PURPOSE: We developed an organotypic genital tubercle culture system in vitro and used it to investigate the direct effects of the hyperestrogenic state on fetal mouse penile and urethral development. MATERIALS AND METHODS: Genital tubercles were dissected from embryonic day 14.5 C57B/L6 male mouse fetuses and cultured using an air-liquid interface on a microporous membrane support soaked in synthetic medium. Cultures were separated into 4 groups. Groups 1 to 3 were supplied with 10 nM dihydrotestosterone, estradiol and 10 nM dihydrotestosterone plus estradiol, respectively. Group 4 was cultured in hormone-free medium. After 36 to 72-hour culture morphological, histological, proliferation, apoptosis, androgen signaling and activating transcription factor 3 analyses were done. RESULTS: The physiological concentration of 10 nM dihydrotestosterone was essential for genital tubercle growth in vitro. Androgen induced growth and urethral development were significantly suppressed by high dose estrogen. Concurrently we observed increased apoptosis and decreased proliferation in the mesenchyma. Androgen signaling was disrupted and activating transcription factor 3, a factor related to hypospadias genesis, was up-regulated. CONCLUSIONS: High dose estrogen suppressed male genital tubercle development in vitro. The organotypic genital tubercle culture system in vitro consisting of urethral epithelial and mesenchymal cells can recapitulate the hormonal sensitivity of fetal penile and urethral development. This method is potentially useful for studying the effects of various factors, particularly endocrine disruptors.

[Snodgrass technique, Duckett repair and bladder mucosa grafting for hypospadias: an analysis of 251 cases].

OBJECTIVE: To present the experience in using the Snodgrass technique, Duckett repair and bladder mucosa grafting for hypospadias. METHODS: We retrospectively reviewed 251 cases of middle and posterior hypospadias treated by the Snodgrass technique, Duckett repair and bladder mucosa grafting from February 1997 to December 2008. RESULTS: The success rates of the Snodgrass technique, Duckett repair and bladder mucosa grafting were 80.3% (53/66) , 76% (19/25) and 78.9% (15/19) for middle hypospadias and 68. 3% (41/60) , 63.6% (14/22) and 88. 1% (52/59) for the posterior type without statistical significant differences (all P > 0.05). Bladder mucosa grafting showed a significantly higher success rate than the other two procedures in either one-stage or two-stage surgical repair of posterior hypospadias (P < 0.05). Duckett repair achieved a significantly higher rate of success in children under 14 years than in the older ones (P < 0.05). CONCLUSION: Of the three surgical options, bladder mucosa grafting is the most suitable for posterior hypospadias, and Duckett repair is recommended for children under 14 years of age.

[Expressions of ATF3 and CTGF and their regulation by estradiol in the prepuce of hypospadias patients].

OBJECTIVE: Estrogen is closely associated with hypospadias. The present study was to explore the molecular mechanism of hypospadias caused by estradiol. METHODS: Fibroblasts obtained from the prepuce of hypospadiac and normal children were cultured in vitro and treated with 17-beta ethinyl estradiol (17-EE) at the concentrations of 1 micromol/L to 0.1 nmol/L for 2 hours, or at 0.1 micromol/L for 0.5, 1, 2, 4, 8, 16 and 24 hours. MTT assay was used to evaluate the effect of 17-EE on the proliferation of the cells, and RT-PCR was employed to detect the expressions of the activating transcription factor-3 (ATF3) and connective tissue growth factor (CTGF) in the hypospadiac tissue. The results were compared with those obtained from the nonhypospadiac tissue. RESULTS: The expressions of ATF3 and CTGF were significantly upregulated in the hypospadiac tissue as compared with the nonhypospadiac group. At the concentration of 1 micromol/L, 17-EE significantly inhibited the proliferation of the cells. ATF3 mRNA was elevated at 1-2 hours, while CTGF mRNA showed no significant changes in 24 hours. CONCLUSION: ATF3 and CTGF are two candidate genes involved in the etiology of hypospadias. And estradiol may induce hypospadias by upregulating the expressions of ATF3 and CTGF.

[Human foreskin acellular matrix graft: a good scaffold for urethral tissue engineering].

OBJECTIVE: To provide evidence of using the human foreskin acellular matrix graft for urethral tissue engineering. METH-ODS: The human foreskin acellular matrix graft was prepared, its safety and biocompatibility as urethral material were determined by histological observation, cytotoxicity test using primary epithelial cells and experiment in vivo. RESULTS: Intact cells were absent from the foreskin acellular matrix graft. The cytotoxicity test showed that the relative growth rate of the cells was between 75% and 99%, and the cytotoxicity of the foreskin acellular matrix graft was grade 1, consistent with the national standard. With the lengthening of time, the foreskin acellular matrix graft became perfectly compatible with the urothelial cells and the urethral multi-layer structure was restored to normal gradually. CONCLUSION: The human foreskin acellular matrix graft, with its low antigenicity and good biocompatibility, could be a good scaffold for urethral tissue engineering.

Methionine synthase A2756G polymorphism influences pediatric acute lymphoblastic leukemia risk: a meta-analysis.

Plenty of studies have investigated the effect of methionine synthase (MTR) A2756G polymorphism on risk of developing pediatric acute lymphoblastic leukemia (ALL), but the available results were inconsistent. Therefore, a meta-analysis was conducted to derive a more precise estimation of the association between MTR A2756G polymorphism and genetic susceptibility to pediatric ALL. The PubMed, Embase, Google Scholar, Web of Science, ScienceDirect, Wanfang Databases and China National Knowledge Infrastructure were systematically searched to identify all the previous published studies exploring the relationship between MTR A2756G polymorphism and pediatric ALL risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were applied to evaluate the strength of association. Sensitivity analysis and publication bias were also systematically assessed. This meta-analysis finally included ten available studies with 3224 ALL cases and 4077 matched controls. The results showed that there was significant association between MTR A2756G polymorphism and risk of pediatric ALL in overall population (AG vs. AA: OR = 1.13, 95%CI = 1.02-1.26, P = 0.02; AG+GG vs. AA: OR = 1.13, 95%CI = 1.02-1.25, P = 0.01; G allele vs. A allele: OR = 1.10, 95%CI = 1.01-1.20, P = 0.03). In the stratification analyses by ethnicity, quality score and control source, significant association was found in Caucasians, population-based designed studies and studies assigned as high quality. In conclusion, this meta-analysis suggests that MTR A2756G polymorphism may influence the development risk of pediatric ALL in Caucasians. Future large scale and well-designed studies are required to validate our findings.

1H-NMR spectroscopy identifies potential biomarkers in serum metabolomic signatures for early stage esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent types of upper gastrointestinal malignancies. Here, we used 1H nuclear magnetic resonance spectroscopy (1H-NMR) to identify potential serum biomarkers in patients with early stage ESCC. METHODS: Sixty-five serum samples from early stage ESCC patients (n = 25) and healthy controls (n = 40) were analysed using 1H-NMR spectroscopy. We distinguished between different metabolites through principal component analysis, partial least squares-discriminant analysis, and orthogonal partial least squares-discriminant analysis (OPLS-DA) using SIMCA-P+ version 14.0 software. Receiver operating characteristic (ROC) analysis was conducted to verify potential biomarkers. RESULTS: Using OPLS-DA, 31 altered serum metabolites were successfully identified between the groups. Based on the area under the ROC curve (AUROC), and the biomarker panel with AUROC of 0.969, six serum metabolites (α-glucose, choline, glutamine, glutamate, valine, and dihydrothymine) were selected as potential biomarkers for early stage ESCC. Dihydrothymine particularly was selected as a new feasible biomarker associated with tumor occurrence. CONCLUSIONS: 1H-NMR spectroscopy may be a useful tumour detection approach in identifying useful metabolic ESCC biomarkers for early diagnosis and in the exploration of the molecular pathogenesis of ESCC.

[Modulation of lung oxidant/antioxidant status by ischemic post-conditioning during ischemia/ reperfusion injury: experiment with rats].

OBJECTIVE: To investigate the effects of ischemic post-conditioning (IPO) on the lung endogenous oxidant-antioxidant system and nitric oxide level during the early stage of ischemia/reperfusion (I/R) injury. METHODS: Twenty four male Sprague-Dawley rats were randomly divided into 3 equal groups: sham-operation (S) group, I/R Group, undergoing ischemia by blocking the lung hilus for 1 h and then reperfusion for 30 min, IPO Group, undergoing blocking the lung hilus for 1 h and then 3 cycles of 10 s ischemia and 10 s reperfusion. Then the rats were killed with their lungs taken out. The levels of glutathione (GSH), nitric oxide (NO), malondialdehyde (MDA), xanthine oxidase (XO), and endogenous antioxidant enzymes, i. e, superoxide dismutase (SOD), and catalase (CAT), and activities of gultathionine peroxidase (GPX) and myeloperoxidase (MPO), a neutrophil accumulation marker, were measured respectively. RESULTS: In IPO group, Compared with I/R group, antioxidant systems such as the levels of SOD, CAT, GPX, and GSH of IPO Group were (41.4 +/- 4.4 ) U/mg, (19.5 +/- 1.6) U/mg, (168 +/- 13) U/mg, and (1.72 +/- 0.26) U/g, all significantly higher than those of I/R Group [(19.6 +/- 2.8) U/mg, (8.4 +/- 0.8) U/mg, (72 +/- 8) U/mg, and (0.89 +/-+/- 0.07) mg/g respectively, all P < 0.05); and the levels of XO, MPO, and MDA of Group IPO were (50 +/- 6) U/g, (5.0 +/- 0.5) U/g, and (0.91 +/- 0.08) nmol/mg respectively, all significantly lower than those of I/R Group [(83 +/- 8) U/g, (7.6 +/- 0.7) U/g and (1.58 +/- 0.17) nmol/mg respectively, all P < 0.05). The endogenous NO level of IPO Group was (93 +/- 7) micromol/g, significantly higher than that of I/R Group [(22 +/- 4) micromol/g, P < 0.01]. CONCLUSION: Post-conditioning at onset of reperfusion reduces lung I/R injury. The lung protection of IPO may be mediated, in part, by inhibiting the oxidant generation and oxidizing, and may be associated with the increasing of the endogenous NO level.

[Clinical Curative Efficacy of Lenalidomide Combined with Chemotherapy for Acute Leukemia and Its Impact on VEGF].

OBJECTIVE: To investigate the clinical efficacy of regimen consisting of lenalidomide combined with chemotherapy for acute leukemia and its impact on vascular endothilial growth factor (vEGF) and basic fibroblast growth factor (bFGF), and to analyze the relationship lenalidomide with therapeutic efficacy of leukemia. METHODS: The patients with newly diagnosed acute myeloid leukemia (except M3) from October 2013 to October 2014 in our hospital were randomly divided into 2 groups: chemotherapy+placebo (CP) group and lenalidomide+chemotherapy (LC) group. In addition, healthy persons were used as healthy controls (HC). The expression of VEGF and bFGF was detected by ELISA, and the therapeutic efficacy for AML patients was analyzed. RESULTS: The therapeutic efficacy in LC group and CP group was 87.9% and 77.2% respectively. Before treatment, the VEGF level in LC and CP groups was obviously higher than that in HC group; after treatment, the VEGF level significanthy decreased, and the decreased degree in LC group was larger than that in CP group. Before treatment, the bFGF level in LC and CP groups was higher than that in HC group; after treatment, the bFGF level decreased, and decreased degree in LC group was larger than that in CP group. CONCLUSION: The lenalidomide combined with chemotherapy can significantly decrease the expression level of VEGF and bFGF, and enhance the remission rate of patients with AML.

Clinical Significance of a Novel Knee Joint Stability Assessment System for Evaluating Anterior Cruciate Ligament Deficient Knees.

OBJECTIVE: To investigate the six degrees of freedom (6DOF) kinematics of anterior cruciate ligament (ACL) deficient knees during gait and to explore the clinical significance of a novel knee joint stability assessment system (Opti_Knee, Innomotion, Shanghai, China) in comparison with imaging and arthroscopic examination. METHODS: Three subjects diagnosed with ACL deficient knees on the basis of preoperative MRI and CT findings were subjected to treadmill gait analysis. Motion of both knees in 6DOF was measured and analyzed with an optical joint kinematics measurement system. Arthroscopic examination, the gold standard, was performed to confirm the final diagnosis and the clinical diagnosis of ACL deficiency by imaging and motion marker techniques compared with this gold standard. RESULTS: Only two of the three subjects diagnosed with ACL deficiency by imaging techniques were later confirmed to have this condition by arthroscopic examination; the third was found to have an intact ACL. When the kinematics of their injured and contralateral knees were compared, abnormalities were found in the two subjects confirmed by arthroscopy to be ACL deficient However, no kinematic difference between the two knees was found in the ACL intact subject. CONCLUSIONS: Opti_Knee (Innomotion) can detect abnormal kinematics in ACL deficient knees and thus provides an effective way of assisting the diagnosis of this condition and has potential for clinical application.

Meta-analysis of the association of MTHFR polymorphisms with multiple myeloma risk.

The association of methylenetetrahydrofolate reductase (MTHFR) polymorphisms with multiple myeloma (MM) risk has been explored, but the results remain controversial. Thus, a meta-analysis was performed to provide a comprehensively estimate. The case-control studies about MTHFR C677T and A1298C polymorphisms with MM risk were collected by searching PubMed, Elsevier, China National Knowledge Infrastructure and Wanfang Databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to assess the strength of association. Overall, no significant association was found between MTHFR A1298C polymorphism and MM risk under all four genetic models (AC vs. AA, OR = 0.99, 95%CI = 0.82-1.20; CC vs. AA, OR = 1.14, 95%CI = 0.77-1.68; recessive model, OR = 1.10, 95%CI = 0.76-1.59; dominant model, OR = 1.01, 95%CI = 0.84-1.22). The risk was also not significantly altered for C677T polymorphism and MM in overall comparisons (CT vs. CC, OR = 1.04, 95%CI = 0.93-1.17; TT vs. CC, OR = 1.16, 95%CI = 0.98-1.37; recessive model, OR = 1.13, 95%CI = 0.98-1.32; dominant model, OR = 1.07, 95%CI = 0.96-1.20). In subgroup analyses by ethnicity, no significant association was observed in both Caucasians and Asians. This meta-analysis suggested that MTHFR polymorphisms were not associated with MM risk.