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Background. Complex carcinogenic mechanisms and the existence of tumour heterogeneity in multiple myeloma (MM) prevent the most commonly used staging system from effectively interpreting the prognosis of patients. Since the microenvironment plays an important role in driving tumour development and MM occurs most often in middle-aged and elderly patients, we hypothesize that ageing of bone marrow mesenchymal stem cells (BM-MSCs) may be associated with the progression of MM. Methods. In this study, we collected the transcriptome data on MM from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Differentially expressed genes in both senescent MSCs and MM tumour cells were considered relevant damaged genes. GO and KEGG analyses were applied for functional evaluation. A PPI network was constructed to identify hub genes. Subsequently, we studied the damaged genes that affected the prognosis of MM. Least absolute shrinkage and selection operator (lasso) regression was used to identify the most important features, and a risk model was created. The reliability of the risk model was evaluated with the other 3 GEO validation cohorts. In addition, ROC analysis was used to evaluate the novel risk model. An analysis of immune checkpoint-related genes, tumour immune dysfunction and exclusion (TIDE), and immunophenotypic scoring (IPS) were performed to assess the immune status of risk groups. pRRophetic was utilized to predict the sensitivity to administration of chemotherapeutic agents. Results. We identified that MAPK, PI3K, and p53 signalling pathways were activated in both senescent MSCs and tumour cells, and we also located hub genes. In addition, we constructed a 14-gene prognostic risk model, which was analysed with the ROC and validated in different datasets. Further analysis revealed significant differences in predicted risk values across the International Staging System (ISS) stage, sex, and 1q21 copy number. A high-risk group with higher immunogenicity was predicted to have low proteasome inhibitor sensitivity and respond poorly to immunotherapy. Lipid metabolism pathways were found to be significantly different between high-risk and low-risk groups. A nomogram was created by combining clinical data, and the optimization model was further improved. Finally, real-time qPCR was used to validate two bortezomib-resistant myeloma cell lines, and the test confirmed that 10 genes were detected to be expressed in resistant cell lines with the same trend as in the high-risk cohort compared to nonresistant cells. Conclusion. Fourteen genes related to ageing in BM-MSCs were associated with the prognosis of MM, and by combining this genotypic information with clinical factors, a promising clinical prognostic model was established.

Background. Extramedullary disease (EMD), an infrequent manifestation of multiple myeloma (MM), can present at diagnosis or develop during the disease course. EMD can be clinically divided into bone-related EMD (EMD-B) and soft tissue-related EMD (EMD-S). The purpose of our study is to investigate the clinical characteristics, survival outcomes, and prognostic factors of MM patients with EMD. Methods. A total of 155 MM patients with EMD were ultimately enrolled in our study by retrieving the Surveillance, Epidemiology, and End Results (SEER) database. The Kaplan–Meier survival curves and log-rank test for overall survival (OS) and myeloma-specific survival (MSS) were conducted to compare each potential variable. Variables with a p value 1 representing adverse prognostic factors. Results. The median age at diagnosis was 63 years old. EMD-B occurred in 99 patients (63.90%), while EMD-S occurred in 56 cases (36.10%). Patients with EMD-S had a significant survival disadvantage in MSS (HR = 1.844, 95% CI 1.117–3.042, p = 0.017) and OS (HR = 1.853, 95% CI 1.166–2.942, p = 0.009) compared to those with EMD-B. Patients with EMD interval ≤24 months were at higher risk of death than those with EMD at diagnosis in MSS (HR = 1.885, 95% CI 1.175–3.346, p = 0.042) and in OS (HR = 1.33, 95% CI 1.119–2.529, p = 0.036). Patients with EMD interval >24 months were at a lower risk of death as opposed to those with EMD at diagnosis. Conclusion. Age at MM diagnosis, site of EMD, and time interval from diagnosis to EMD occurrence were independent prognostic factors in MM patients with EMD. EMD-B bore a better prognosis than EMD-S.

IntroductionPlasmablastic lymphoma(PBL)，an extremely rare subtype of B-cell non-Hodgkin lymphoma, is characterized by aggressiveness, rapid progression and bleak prognosis. Neither standardized regimen nor consensus for PBL treatment has been established.Material and methodsWe retrospectively analyzed the clinicopathologic characteristics, therapeutic modalities and survival outcomes of 418 patients registered in the Surveillance, Epidemiology, and End Results (SEER) database from 2008 to 2016 and 21 (19 treated) patients in our institution. Kaplan-Meier survival curves and log-rank test for overall survival and disease-specific survival were performed to compare each variable. Variables with statistical significance in the univariate Cox regression were incorporated into the multivariate model to determine the independent prognostic factors.ResultsIn patient cohort from SEER, PBL has a striking male predilection. The median OS for all PBL patients was 17 months. The 1-year,3-year and 5-year OS rate were 54.4%, 40.4% and 37.2% respectively.Chemotherapy alone or chemotherapy combined with radiotherapy could significantly reduce the risk of death and extend the patients’ survival, yielding HR of 0.209(95%CI 0.152-0.288) and 0.187(95%CI 0.089-0.394), respectively. Radiation alone seemed useless. All patients from our institution were HIV-negative. The main therapeutic regimens were CHOP or CHOPE, DA-EPOCH, DHAP and ESHAP. Complete response was achieved in only 3 patients, while partial response in 10 patients. The median OS was 7 months. Fourteen patients later died of the disease progression.ConclusionsPrevious malignancy history, Ann Arbor stage and therapeutic modality were independent prognostic factors. Bortezomib combined with DA-EPOCH may serve as an effective regimen for PBL. The optimal therapeutic modality necessitates further exploration.

IntroductionAutophagy functions as a prosurvival mechanism in multiple myeloma (MM).The objective of this research was to establish an autophagy-related gene (ARG) signature for predicting the survival outcomes of MM patients with TP53 mutations.Material and methodsInformation about MM patients with TP53 mutations was downloaded from Gene Expression Omnibus (GEO) database. Cox proportional hazard regression was employed to determine the independent prognostic ARG and construct a risk signature. Time-dependent receiver-operating characteristic (t ROC) curve was used to explore the predictive accuracy of the prognostic model. A nomogram was constructed to give a more precise prediction of the probability of 5-year, 8-year and 10-year overall survival (OS). In addition, we utilized the CIBERSORT algorithm to explore the distribution difference of 22 immune-infiltrating cells.ResultsThree differentially expressed ARGs (CASP8, MAPK8, RB1CC1) were finally incorporated to construct the risk model. Area under the curve (AUC) of corresponding tROC curve for 5-year,8-year and 10-year OS were 0.735, 0.686 and 0.662, respectively. MM patients were categorized into high and low-risk group in accordance with the median threshold value (-1.724549). ARG-based risk score model was an independent prognostic element correlated with OS, giving an hazard ratio (HR) of 3.29 (95%CI 2.35-4.60, PConclusionsWe established a three-ARGs risk signature which manifested an independent prognostic factor. The nomogram was testified to perform well in forecasting the long-term survival of TP53-mutated MM patients.

Background To evaluate the efficacy and safety of rituximab-based combination therapy for Waldenstrom macroglobulinemia (WM), we conducted this meta-analysis by pooling the rates of overall response, major response, complete response, and grade ≥3 hematological adverse events. Methods and materials We searched for relevant studies in the databases of PubMed, Web of Science, Embase, and the Cochrane Library. The qualitative assessment of all the included articles was conducted with reference to the Newcastle-Ottawa Scale. A random-effects model was selected to perform all pooled analyses. Results We identified altogether 22 studies with a total of 806 symptomatic WM patients enrolled. The pooled analysis indicated that the rituximab-based combination therapy achieved an overall response rate (ORR) of 84% (95% CI: 81%-87%), a major response rate (MRR) of 71% (95% CI: 66%-75%), and a complete response rate (CRR) of 7% (95% CI: 5%-10%). Rituximab plus conventional alkylating agents-containing chemotherapy (subgroup A) yielded an ORR of 86% (95% CI: 81%-89%), an MRR of 74% (95% CI: 69%-79%), and a CRR of 8% (95% CI: 4%-14%). Rituximab plus purine analog (subgroup B) resulted in an ORR of 85% (95% CI: 79%-89%), an MRR of 74% (95% CI: 66%-81%), and a CRR of 9% (95% CI: 4%-15%). Rituximab plus proteasome inhibitor (subgroup C) resulted in an ORR of 86% (95% CI: 81%-90%), an MRR of 68% (95% CI: 58%-77%), and a CRR of 7% (95% CI: 3%-11%). Rituximab plus immunomodulatory drug (subgroup D) attained relatively lower response rates, with an ORR of 67% (95% CI: 51%-81%), an MRR of 56% (95% CI: 27%-83%), and a CRR of 5% (95% CI: 1%-12%). Common grade ≥3 hematological adverse events consisted of neutropenia (33%, 95% CI: 17%-52%), thrombocytopenia (7%, 95% CI: 3%-11%), and anemia (5%, 95% CI: 3%-9%). Conclusion Rituximab in combination with an alkylating agent, purine analog, or proteasome inhibitor is highly effective with tolerable hematological toxicities for WM.

Background: Previous studies have revealed that quantitative hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (qAnti-HBc) levels can be used as predictors of treatment response in both interferon-α and nucleoside analogue therapies. Few data have been published regarding the relationship between quantitative HBsAg or Anti-HBc levels and liver fibrosis stages in patients with chronic hepatitis B (CHB). Methods: We conducted a cross-sectional study of treatment-naïve CHB patients. A total of 624 CHB patients were recruited. We assessed the serum HBsAg and qAnti-HBc levels, HBV DNA levels, HBV genotypes, BCP/PC mutations, histological fibrosis staging by Scheuer classification. Results: In HBeAg (+) patients, the S0-1 subjects had significantly higher serum HBsAg and lower qAnti-HBc levels than the S2-4 subjects (both p 0.05). Serum qAnti-HBc levels showed a moderate positive correlation with fibrosis scores (r = 0.383, p

Invasive fungal infections especially in immunocompromised patients represent a dominating cause of mortality. The most commonly used antifungal agents can be divided into three broad categories, including triazoles, echinocandins and polyenes. Antifungal resistance is on the increase, posing a growing threat to the stewardship of immunocompromised patients with fungal infections. The paucity of currently available antifungals leads to the rapid emergence of drug resistance and thus aggravates the refractoriness of invasive fungal infections. Therefore, deep exploration into mechanisms of drug resistance and search for new antifungal targets are required. This review highlights the therapeutic strategies targeting Hsp90, calcineurin, trehalose biosynthesis and sphingolipids biosynthesis, in an attempt to provide clinical evidence for overcoming drug resistance and to form the rationale for combination therapy of conventional antifungals and agents with novel mechanisms of action. What's more, this review also gives a concise introduction of three new-fashioned antifungals, including carboxymethyl chitosan, silver nanoparticles and chromogranin A-N46.

Background: Primary lymphoma of bone (PLB) is an extremely rare malignancy arising in the skeletal system. There is no consensus over the best definition of PLB. Most of the published articles are single-institutional retrospective studies with a limited sample size. The rarity of PLB and discrepancies on diagnostic criteria has resulted in a vague understanding of PLB. Methods We retrospectively analyzed the clinical characteristics and prognostic factors of 2558 PLB patients who were registered in the Surveillance, Epidemiology, and End Results (SEER) database from 1973 to 2016. Survival rates were calculated using the Kaplan–Meier method. The effects of various factors on survival outcomes were analyzed by using the log-rank test. Univariate and multivariate analyses were conducted by using the Cox proportional hazards model to determine independent prognostic factors. Results: The median follow-up time of all eligible patients was 58 months. There seemed no sex preponderance in PLB incidence. The most involved sites are axial skeletons. The most common histological subtype was diffuse large B-cell lymphoma. The 3-, 5-, 10-, and 20-year overall survival (OS) rates were 70.70%, 65.70%, 54.40% and 39.50%, respectively. PLB patients whose primary tumor sites were appendicular and craniofacial skeletons had a significant survival advantage [hazard ratio (HR) = 0.694, 95% confidence interval (CI) 0.552–0.872; HR = 0.729, 95% CI 0.597–0.889, respectively] over those with axial skeletons as primary tumor sites. Patients with Hodgkin lymphoma, non-Hodgkin lymphoma (NHL)–mature B-cell lymphoma, and NHL-precursor-cell lymphoblastic lymphoma also had a significant OS advantage (HR = 0.392, 95% CI 0.200–0.771; HR = 0.826, 95% CI 0.700–0.973; and HR = 0.453, 95% CI 0.223–0.923, respectively). Patients with Ann Arbor stage III–IV at diagnosis were at higher risk of death than those with stage I–II (HR = 1.348, 95% CI 1.107–1.641). Chemotherapy was an independent favorable prognostic factor (HR = 0.734, 95% CI 0.605–0.890). Conclusions: Primary anatomic site, histology type, higher Ann Arbor stage and chemotherapy were independent prognostic factors. Chemotherapy played a pivotal role in PLB treatment.

Galectin-3, a microglia/macrophage-derived inflammatory mediator, plays a role in the stroke progression. In this single-center prospective study, we included 288 consecutive patients with a first-ever acute ischemic stroke to assess the association between galectin-3 serum level and clinical severity at admission and outcome at discharge by univariate and multivariate logistic regression. The results were presented as odds ratios (OR) and 95% confidence intervals (CI). Patients with high severity and poor outcomes had higher serum levels of galectin-3 (P

Lymphomatoid granulomatosis (LYG) is an extremely rare angio-centric and angio-destructive B-cell lymphoproliferative disease. Driven by Epstein-Barr virus (EBV), LYG predominantly involves the bilateral lungs. Commonly presenting as multiple nodules in the lung, pulmonary LYG can masquerade as various infectious diseases, vasculitis, lung cancer, or other metastatic neoplasm. It is difficult to be diagnosed and is always neglected by clinicians. No standardized therapeutic regimens for LYG has been established yet now. Hemophagocytic lymphohistiocytosis (HLH), a life-threatening condition caused by abnormal activation of macrophages and T-cells, is characterized by fever, hepatosplenomegaly, pancytopenia, hypercytokinemia, and the presence of hemophagocytosis within the bone marrow, liver, spleen, or other lymphatic tissue. We herein report a 55-year-old man with recurrent fever, severe jaundice, and multiple high-density opacities and nodules in both lungs, who was finally diagnosed with pulmonary LYG (Grade 3) manifested with secondary HLH. Administration of HLH-1994 protocol led to the rapid control of the symptoms caused by HLH. Rituximab-based combination therapy was useful yet LYG (Grade 3) progressed rapidly. This case demonstrates that tissue biopsy is essential for early pathological diagnosis and effective treatment of LYG.

Objective To evaluate the relationship between the rs10795668 single nucleotide polymorphism (SNP) and the colorectal cancer (CRC) in north China Han population. Methods The genotype of rs10795668 SNP was detected by PCRRFLP analysis in 113 colon cancer patients, 69 rectal cancer patients, and 192 age and sex matched controls. Unconditional logistic regression were used to comparatively analyze the genotype between patients and the controls adjusted by age and sex. Results No significant difference of rs10795668 SNP was detected between colorectal cancer patients and normal controls, but it was found that an existence of interaction of gene and sex in colorectal cancer, and women with AA+AG genotype may have lower risk of colon cancer (OR3.05, 95% CI 1.47-6.35; P=0.00078). Conclusion The AA+AG genotype of rs10795668 SNP is associated with the genetic susceptibility of colon cancer, but not of rectal cancer, in north China Han women. DOI: 10.11855/j.issn.0577-7402.2015.10.10

Background: Multiple myeloma (MM) is the second most common hematological neoplasm. Wide administration of bortezomib significantly improves the survival of MM patients compared with conventional chemotherapy. Bromodomain-containing protein 4 (BRD4) inhibitors also have been demonstrated to retard cell proliferation and induce cellular apoptosis in various cancers. However, it is unclear whether the BRD4 inhibitor nitroxoline plus bortezomib has a synergistic anti-tumor effect on MM. Methods: Cell viability was determined via 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle and cell apoptosis were assessed via flow cytometry. Protein expression levels were determined via western blotting. The expression of apoptosis-related proteins in xenograft tissue were detected by means of immunohistochemistry. Results: Treatment with nitroxoline or bortezomib suppressed cell proliferation, and caused G0/G1 phase arrest and apoptosis in H929 and RPMI8226 cells. Furthermore, nitroxoline intensified the retardation of cell proliferation, as well as further enhanced the G0/G1 phase arrest and apoptosis induced by bortezomib in H929 and RPMI8226 cells. The western blot analysis revealed that nitroxoline or bortezomib treatment markedly diminished the levels of Bcl-2 and cyclin D1, and increased the levels of p21, Bax, cleaved PARP and cleaved caspase-3. Combination of these two agents was observed to result in further marked changes on these levels compared with nitroxoline or bortezomib treatment alone. What is more, in the xenograft tumor model, combinative treatment markedly inhibited tumor growth compared with the single drug treatment. Conclusion: Combination of bortezomib with nitroxoline has a synergistic anti-tumor activity in MM cells and may be a novel treatment method for MM.

During the past decades, agents with novel mechanisms of action, such as monoclonal antibodies (MAbs) and histone deacetylase inhibitors (HDACis) have been applied to treat relapsed or refractory multiple myeloma (RRMM). The treatment outcomes of MAbs versus HDACi in combination with bortezomib or lenalidomide plus dexamethasone remain unknown. We conducted this meta-analysis to compare indirectly the efficacy and safety of MAbs and HDACis in combination with bortezomib or lenalidomide plus dexamethasone. Six trials (eight articles) were included in the meta-analysis with 3270 RRMM patients enrolled. We synthesized hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS), risk ratios (RRs) for complete response (CR),very good partial response (VGPR), overall response (OR), progressive disease plus stable disease (PD + SD) and common at least grade 3 adverse events, and their corresponding 95%confidence intervals (95% CI). Treatment with MAbs in combination with bortezomib or lenalidomide plus dexamethasone resulted in longer PFS (HR 0.83, 95% CI: 0.66–0.98), fewer incidences of at least grade 3 thrombocytopenia (RR 0.35, 95% CI: 0.23–0.53), neutropenia (RR 0.70, 95% CI: 0.51–0.96), and sense of fatigue (RR 0.37, 95% CI: 0.17–0.82) than HDACis. The daratumumab plus bortezomib or lenalidomide and dexamethasone might significantly improve PFS in comparison with HDACis plus bortezomib or lenalidomide and dexamethasone (HR 0.55, 95% CI: 0.40–0.74). In conclusion, MAbs may be superior to HDACis in achieving longer PFS and may be better tolerated when in combination therapy with bortezomib or lenalidomide plus dexamethasone.

Objective To evaluate the association between RASSF1A Ala133Ser single nucleotide polymorphism (SNP) and colorectal cancer (CRC) in patients of Han population in north China. Methods RASSF1A SNP was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis in 109 colon cancer (CC) patients, 67 rectal cancer (RC) patients and 189 age and sex matched healthy people (as controls). Unconditional logistic regression was used to analyze the gene-disease association and gene-sex interaction. Results The RASSF1A Ala133Ser SNP in CRC patients had no significant difference with that in normal control samples, but the interaction of genotype and sex existed in rectal cancer, Ala/Ser+Ser/Ser genotypes of RASSF1A gene increased the risk of rectal cancer in women (OR=3.78, 95%CI 1.31-10.89). Conclusion The RASSF1A 133Ser allele is associated with rectal cancer in women, but not colon cancer. DOI: 10.11855/j.issn.0577-7402.2015.03.10

Background Accumulating evidence has indicated that the dysregulation of immunological environment has an important role in the pathogenesis of myelodysplastic syndromes (MDS). The previous studies about the levels of the inflammatory cytokines in MDS, such as TNF-α, IFN-γ, IL-6, IL-8, and IL-17, have yielded controversial results. Thus, we performed a meta-analysis to assess the levels of these inflammatory cytokines in MDS. Methods A systematic search in PubMed, MEDLINE, Cochrane Library, Web of Science, CNKI, and CBM was conducted to find eligible studies. Meta-analyses were performed using STATA 12.0 for Windows. Heterogeneity between included studies was assessed by I test. We chose SMD as the summary statistic. Results A total of 697 individuals from 11 studies were included in this study. Our results suggest the levels of TNF-α, IL-6, IL-8 were significantly higher in MDS patients compared with controls, SMD and 95%CI was 1.48 (0.60, 2.36), 0.71 (0.16, 1.25) and 0.69 (0.28, 1.09), respectively. Moreover, the levels of IL-17 have decreased in the high-risk MDS, the SMD and 95% CI was 2.96 (0.78, 5.15). Conclusion A close association between immunological microenvironment disorders and the pathogenesis of MDS was revealed in this meta-analysis. More importantly, the profiles of inflammatory cytokines appear to change along the progression of the disease.

Previous studies have shown that hepatitis B core antibody (anti-HBc) levels vary during different phases of disease in treatment-naïve chronic hepatitis B (CHB) patients and can be used as a predictor of both interferon-α and nucleoside analogue therapy response. However, there is no information on the association between the quantitative serum anti-HBc (qAnti-HBc) level and liver inflammation in CHB patients. Therefore, we investigated these relationships in a large cohort of treatment-naïve CHB patients. A total of 624 treatment-naïve CHB patients were included in the study. The serum qAnti-HBc level was moderately correlated with ALT and AST levels (P

To develop the rationales for ovarian cancer-specific protein profiles in serum and to analyze the protein profiles of multidrug resistance P-glucoprotein (MDR1) and multidrug resistance-associated protein (MRP) positive and negative expression sets for a rapid and sensitive serum protein pattern.Serum protein profiles from 36 epithelial ovarian cancer cases were compared with 30 healthy controls using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (DELDI-TOF-MS). Blinded test was conducted subsequently for identification of the protein pattern. Expression of MDR and MRP were detected in set of training cases by immunohistochemistry. The spectra were analyzed statistically between positive and negative groups.Twenty-nine peaks were significantly different between ovarian cancer and healthy controls (P0.01, 15 peaks up-regulated and 14 down-regulated). A set of three peaks, at 5 486, 6 463 and 8 575 m/z respectively, were selected from 29 sense peaks as an ovarian cancer biomarker. The sensitivity was 100% and specificity 93.33%. Identification by blinded validation indicated a positive predictive value of 90%. MDR1 expression in ovarian cancer was 69.4 %. Twenty peaks were significantly different between positive and negative sets (P0.01). MRP expression in ovarian cancer was 63.8%. But one peak was detected (P0.01).It was an ideal pattern for employing the SELDI mass spectrum approach to diagnose ovarian cancer and select the multidrug resistance cases. Serum biomarkers for detecting drug resistance in ovarian cancer can be established on the basis of MDR1 immunohistochemistry.

To search the tissue biomarker in mycosis fungoides (MF) patients by surface enhanced laser desorption/ionization-time of flight-mass spectrometry (SELDI-TOF-MS).Skin specimens were collected from 12 MF patients and 15 normal controls to prepare solution of protein. CM10 Proteinchip was used to detect the biomarkers for MF. Differentially expressed protein was identified by immuno capturing.The expression intensity levels of 24 proteins were different between the MF patients and controls. By searching in SWISS-PRO database and literature, the 3498 and 10 837 peaks were found to accord with HNP3 and S100A8 proteins respectively. By immuno capturing, 10 837 could be identified as S100A8 with a special antibody against S100A8.A quick, easy, and high throughout proteome analytic method, SELDI-TOF-MS can identify the differential expressed proteins from MF tissue, thus offering a unique platform for biomarker detection of MF.

Serum samples from endometrial cancer (EC) patients and healthy females were analyzed using surface-enhanced laser desorption-ionization time-of-flight mass spectrometry (SELDI-TOF-MS) to discover the potential diagnostic biomarker for detection of EC. A preliminary training set of spectra derived from 40 EC patients and 30 healthy women were used to develop a proteomic model that effectively discriminated cancer patients from healthy women. The training set had a specificity of 100% and sensitivity of 92.5% in the EC detection. A blind test set, including 20 new cancer cases and 10 healthy women, was used to validate the sensitivity and specificity of this multivariate model, which had a corresponding results of 60% in specificity and 75% in sensitivity, respectively. The combination of SELDI-TOF-MS with bioinformatics tools could help find new biomarkers and establish the detection of EC with high sensitivity and specificity.

To increase the success rate of primary culture of human periodontal ligament fibroblasts (HPLF), and to establish an experimental model for studying HPLF in vitro.The primary cells were isolated from human periodontal ligament by explants with enzymatic digestion method. Morphological analysis and immunocytochemical staining were used to characterize the cell lineage, and growth curve assay to evaluate the biological features of HPLF.The success rate of primary culture of HPLF was 77.8%. Cultured cells were spindle-shaped, and had a positive reaction to antibodies against vimentin, and a negative reaction to antibodies against keratin. Their morphological and biological characteristics were similar to those of typical HPLF. Growth of HPLF obtained by this method was satisfactory.The success rate of primary culture of HPLF is significantly increased by explants combined with enzymatic digestion. The method is simple and feasible.