Search

Background: Colorectal cancer (CRC) is one of the most prevalent gastrointestinal malignancies. The incidence of CRC has been rapidly increasing in China. Transferrin receptor 1 (TfR1) is a key regulator of cellular iron homeostasis. Several studies have demonstrated TfR1 overexpression in a variety of human tumors, but the association between TfR1 and CRC remains unclear. Methods: TfR1 expression was evaluated in six CRC cell lines and tumor tissues. A total of 201 CRC patients were included for immunohistochemistry and 19 pairs of frozen tissues were used for real-time PCR. Cell proliferation, cell cycle, cell migration and invasion, and in vivo carcinogenesis were tested after downregulation of TfR1 by lentivirus. Protein microarray and Western blot analyses were used to explore the underlying mechanisms of TfR1 in CRC. Results: TfR1 expression was higher in CRC tissues than in normal tissues (57.2% vs 22.9%, P＜0.001). TfR1 expression was obviously higher in CRC tissues with well differentiation (P＝0.008), no lymph node metastasis (P＝0.002), no distant metastasis (P＝0.006), no vascular invasion (P＜0.001) and early TNM stage (P＝0.013). CRC patients with TfR1-positive expression had a better survival than those with TfR1-negative expression (P＝0.044). Downregulation of TfR1 expression inhibited cell proliferation, promoted cells from G1 phase to S phase and facilitated cell migration and invasion. Knockdown of TfR1 also suppressed tumor growth in BALB/C-nu mice. Protein microarray and Western blot analyses showed that the Janus protein tyrosine kinase/signal transducer and activator of transcription pathway was activated along with downregulation of TfR1 expression. Conclusion: Though TfR1 was overexpressed in colorectal cancer tissues, there was evidence that downregulation of TfR1 could promote cancer progression.

Intratumor heterogeneity (ITH) of T cell receptor (TCR) repertoire in different T-cell subsets and locations in lung adenocarcinomas was unclear. Here, we investigated percentages and TCR repertoire of freshly isolated CD4+ and CD8+ tumor infiltrating lymphocytes (TILs) in tumor centers and margins by flow cytometry on 80 tumor samples from 20 patients and high-throughput TCR sequencing on 27 and 25 samples of CD4+ and CD8+ TILs from seven patients. Our results demonstrated that amount and TCR repertoire diversity of CD4+ TILs were significantly higher than those of CD8+ TILs and moreover substantial ITH regarding amount and TCR repertoire of CD4+ and CD8+ TILs were observed. Additionally, ITH of CD4/CD8 T-cell ratio and CD8+ TIL repertoire across center regions was lower than that across margin regions. The amount and TCR repertoire ITH of CD4+ and CD8+ TILs and mean clonality of CD8+ TILs in tumor centers were associated with relapse. Our study provides insights into amount and TCR repertoire ITH of CD4+ and CD8+ TILs in tumor centers and margins as well as corresponding association with prognosis in lung adenocarcinoma patients, suggesting potential clinical significance of TCR repertoire.

The management of patients with triple‑negative breast cancer is challenging due to the lack of effective therapeutic options, aggressive behavior and relatively poor prognosis. Xi Huang pills (XHP) are a well‑known traditional Chinese medicine that demonstrate anticancer activities. The aim of the present study was to investigate the antitumor effects of XHP on MDA‑MB‑231 cells in vitro and in vivo, and its potential underlying molecular mechanisms. In the present study, an MTT assay was used to evaluate the antiproliferative activity of XHP on MDA‑MB‑231 cells. In order to investigate the effects further, cell cycle distribution, apoptosis and mitochondrial membrane potential assays were performed, as well as western blot analyses. In addition, a tumor xenograft model was employed to investigate the effects of XHP in vivo. The results of the MTT assay demonstrated that the viability of MDA‑MB‑231 cells was markedly inhibited by XHP in a dose‑ and time‑dependent manner. The inhibitory effect of XHP on the viability of MDA‑MB‑231 cells was greater when compared with MCF‑10A cells. An increase in apoptosis and loss of mitochondrial membrane potential was observed following 4, 8 and 12 mg/ml XHP treatment of MDA‑MB‑231 cells. The protein expression levels of cleaved caspase‑3 were increased by 1.62‑, 2.13‑ and 2.19‑fold, respectively, when compared with the untreated controls, whereas no effects on the expression of B‑cell lymphoma 2 (Bcl‑2) or Bcl‑2‑associated X protein (Bax) were observed. The results of the cell cycle distribution assay analysis demonstrated that XHP treatment arrested cells at the G2/M phase. In addition, XHP treatment decreased the expression of cyclin A and increased the expression of p21Cip1. In vivo experiments revealed that XHP inhibited the growth of MDA‑MB‑231 xenograft tumors without body weight loss, and demonstrated similar effects on the protein expression levels of cleaved caspase 3, cyclin A and p21Cip1 as observed in vitro. In conclusion, the viability of MDA‑MB‑231 cells was inhibited by XHP in a dose‑dependent, time‑dependent and cell‑selective manner in vitro, and the potential underlying mechanisms may involve apoptosis and cell cycle arrest at the G2/M phase. XHP may induce apoptosis in MDA‑MB‑231 cells via the intrinsic pathway, which does not involve the Bcl‑2/Bax ratio. G2/M phase arrest may have been due to the integrated action of decreased cyclin A expression and increased p21Cip1 expression. In addition, XHP inhibited the growth of xenograft tumors in the absence of body weight loss in vivo.

Lysosomal protein transmembrane 4β (LAPTM4B) is an oncogene that is overexpressed in a number of various types of human cancer. There are two known alleles of LAPTM4B: LAPTM4B*1 and LAPTM4B*2. The present study assessed the association between LAPTM4B polymorphisms and the susceptibility to diffuse large B-cell lymphoma (DLBCL) and its prognosis. LAPTM4B genotypes were determined using polymerase chain reaction analysis in 164 DLBCL and 350 healthy control cases. The association between LAPTM4B polymorphisms and the risk of DLBCL was analyzed using unconditional logistic regression. Differences in patient survival were calculated using Kaplan-Meier analysis. The present study indicated no significant differences (P>0.05) in the frequency of LAPTM4B*2 alleles between DLBCL cases (26.5%) and controls (24.1%). The risk of DLBCL was slightly increased in cases with the LAPTM4B*1/2 genotype [odds ratio (OR)=1.160; 95% confidence interval (CI)=0.781-1.724] or the LAPTM4B*2/2 genotype (OR=1.446; 95% CI=0.648-3.227) compared with those with the LAPTM4B*1/1 genotype. There was no significant association between the presence of the LAPTM4B*2 allele and overall survival (OS) and disease-free survival (DFS) in patients with DLBCL (P=0.399 and 0.520, respectively). However, there was a tendency for patients with LAPTM4B*2 and International Prognostic Index (IPI) score 3-5 to have longer OS and DFS (P=0.126 and 0.109, respectively). These findings suggest that genetic polymorphisms of LAPTM4B is not a risk factor for the development of DLBCL, but the LAPTM4B*2 allele may a better prognostic indicator in patients with IPI score 3-5 in DLBCL.

Breast cancer 1 (BRCA1) is one of the most common tumor suppressor genes in breast cancer. The BRCT domain of BRCA1 has been shown to have a critical role in tumor suppression. In a previous study, two de novo BRCT missense mutations of BRCA1, G1763V and L1786P were identified from Chinese females with familial breast cancer. In the present study, the function of these two novel mutations were assessed by bioinformatics analysis and a series of experiments investigating cell proliferation, cell cycle and chemotherapy combination. Although bioinformatics analysis indicated that the mutants may be deleterious, a series of experiments revealed that the two mutants significantly reduced the growth and increased cell apoptosis similar to the function of BRCA1 wild type. Furthermore, no synergistic effect between the Olaparib and BRCA1 mutation was noted on cell apoptosis. These results demonstrated that these two mutations did not affect the tumor suppressor function of BRCA1. It was concluded that not all BRCA1 missense mutations are pathogenic and that any new BRCA1 mutation should be assessed for its effect on the tumor suppressor function of BRCA1.

Background R-CHOP has significantly improved survival rates of patients with diffuse large B cell lymphoma (DLBCL) by ~20% as compared to CHOP. CD20 antigen, highly expressed on more than 80% of B-cell lymphomas, is the target for rituximab. The goal of our study was to examine polymorphism in the CD20 gene in Chinese DLBCL population and whether CD20 gene polymorphism is associated with clinical response to R-CHOP. Method CD20 gene polymorphism was detected in the entire coding regions including 6 exons by polymerase chain reaction (PCR)-sequencing assay in 164 patients with DLBCL. Among them, 129 patients treated with R-CHOP as frontline therapy (R ≥ 4 cycles) were assessable for the efficacy. Results Polymorphisms at three single nucleotides (SNP) were identified in the entire coding regions of the CD20 gene in the 164 patients. One of them, CD20 Exon2 [216] was found to be highly correlated with response to R-CHOP. Patients with homozygous C genotype showed a trend toward higher overall response rate than others with CT plus TT genotype (90.6% vs. 79.5%; P =0.166). A trend toward higher complete remission (CR) rate was observed in patients with homozygous C genotype (67.4%) compared with CT plus TT genotype (47.1%) (P = 0.091). Conclusion These results suggest that there are 3 SNPs in CDS of the CD20 gene in Chinese DLBCL population. The CC genotype at Exon2 [216] appears to be associated with favourable response to R-CHOP.

Background Latexin, also known as endogenous carboxypeptidase inhibitor (CPI), has been found to inhibit mouse stem cell populations and lymphoma cell proliferation, demonstrating its potential role as a tumor suppressor. Our previous study also suggested a correlation between latexin expression and malignant transformation of immortalized human gastric epithelial cells. Here, we examined latexin expression in human gastric carcinomas and investigated the effect of differential latexin expression on proliferation of gastric cancer cells in vitro and in vivo. Methods Monoclonal antibody against human latexin was prepared and immunohistochemical analysis was performed to detect latexin expression in 41 paired gastric carcinomas and adjacent normal control tissues. Human gastric cancer cells MGC803 (latexin negative) stably transfected with LXN gene and BGC823 cells (latexin positive) stably transfected with antisense LXN gene were established for anchorage-dependent colony formation assay and tumorigenesis assay in nude mice. Differentially expressed genes in response to exogeneous latexin expression were screened using microarray analysis and identified by RT-PCR. Bisulfite sequencing was performed to analyze the correlation of the methylation status of LXN promoter with latexin expression in cell lines. Results Immunohistochemical analysis showed significantly reduced latexin expression in gastric carcinomas (6/41, 14.6%) compared to control tissues (31/41, 75.6%) (P < 0.05). Overexpression of LXN gene in MGC803 cells inhibited colony formation and tumor growth in nude mice. Conversely, BGC823 cells transfected with antisense LXN gene exhibited enhanced tumor growth and colony formation. Additionally, several tumor related genes, including Maspin, WFDC1, SLPI, S100P, and PDGFRB, were shown to be differentially expressed in MGC803 cells in response to latexin expression. Differential expression of Maspin and S100P was also identified in BGC823 cells while latexin expression was downregulated. Further bisulfite sequencing of the LXN gene promoter indicated CpG hypermethylation was correlated with silencing of latexin expression in human cells. Conclusions Latexin expression was reduced in human gastric cancers compared with their normal control tissues. The cellular and molecular evidences demonstrated the inhibitory effect of latexin in human gastric cancer cell growth and tumorigenicity. These results strongly suggest the possible involvement of latexin expression in tumor suppression.