Silencing of XRCC4 increases radiosensitivity of triple-negative breast cancer cells.

BACKGROUND: Radiotherapy is an important locoregional treatment, and its effect on triple-negative breast cancer (TNBC) needs to be enhanced. The aim of the present study was to investigate the potential effects of XRCC4 on radiosensitivity of TNBC. METHODS: The RNAi technique was implemented to establish the TNBC stable cell line with XRCC4 knockdown. MTT assay was used to detect the effect of XRCC4 knockdown on cell proliferation. Western blot and immunohistochemistry assays were employed to identify protein expression. Colony assay was performed to detect the effect of XRCC4 knockdown on the colony formation ability of TNBC cells with radiation treatment. Comet assay was conducted to evaluate the influence of XRCC4 silencing on DNA repair activity in ionizing radiation. In addition, we performed a survival analysis based on data in TCGA database. RESULTS: XRCC4 knockdown by lentivirus-mediated shRNA had no significant effect on proliferation of TNBC cells. Knockdown of XRCC4 could substantially increase the sensitivity of TNBC cells to ionizing radiation. The DNA damage level was detected to be increased in the XRCC4 knockdown group, indicating there was a significant repair delay in the XRCC4-deleted cells. Clinical sample analysis exhibited that there were various XRCC4 expression in different patients with TNBC. Moreover, survival analysis showed that high expression of XRCC4 was significantly associated with poor progression-free survival after radiotherapy in TNBC patients. Conclusion: Our findings suggest that XRCC4 knockdown sensitizes TNBC cells to ionizing radiation, and could be considered as a novel predictor of radiosensitivity and a promising target for TNBC.

Long non-coding RNA MALAT1 promotes proliferation and invasion via targeting miR-129-5p in triple-negative breast cancer.

BACKGROUND: Long non-coding RNA Metastasis associated lung adenocarcinoma transcript 1(lncRNA MALAT1) play important roles in tumor progression. In the present study, we determined the regulatory function of MALAT1 in triple-negative breast cancer (TNBC). METHODS: A total of 43 cases of TNBC tissues and paired adjacent non-tumor tissues were collected for the research. MALAT1 expression was explored by qRT-PCR. In vitro functional validation experiments were used to determine the effect of MALAT1 on TNBC progression. We further identified the downstream target miRNAs for MALAT1. RESULTS: Relative expression of MALAT1 was increased in TNBC tissues and cell lines. High MALAT1 expression was closely correlated to advance clinical features and poor overall survival in TNBC patients. Function assay showed that MALAT1 silencing significantly decreased cell proliferation, migration, and invasion. Flow cytometry assay revealed that MALAT1 inhibition significantly induced cell cycle arrest in the G0/G1 phase. In addition, we showed that the roles of MALAT1 on TNBC cells progression was mediated by miR-129-5p. CONCLUSION: Our results demonstrated that the "MALAT1-miR-129-5p" axis might play an important role in the progression of TNBC, thereby might provide a potential therapeutic strategy for the treatment of TNBC.

Multilocus sequence typing and clonal population genetic structure of Cyclospora cayetanensis in humans.

To investigate the prevalence of Cyclospora cayetanensis in a longitudinal study and to conduct a population genetic analysis, fecal specimens from 6579 patients were collected during the cyclosporiasis - prevalent seasons in two urban areas of central China in 2011-2015. The overall incidence of C. cayetanensis infection was 1·2% (76/6579): 1·6% (50/3173) in Zhengzhou and 0·8% (26/3406) in Kaifeng (P 0·05). All the isolates clustered in the C. cayetanensis clade based on the small subunit ribosomal RNA gene sequence phylogenetic analysis. There were 45 specimens positive for all the five C. cayetanensis microsatellite loci, and formed 29 multilocus genotypes (MLGs). The phylogenetic relationships of 54 distinct MLGs (including 25 known reference MLGs), based on the concatenated multilocus sequences, formed three main clusters. A population structure analysis showed that the 79 isolates (including 34 known reference isolates) of C. cayetanensis produced three distinct subpopulations based on allelic profile data. In conclusion, we determined the frequency of C. cayetanensis infection in humans in Henan Province. The clonal population structure of the human C. cayetanensis isolates showed linkage disequilibrium and three distinct subpopulations.

Modification of cytokine-induced killer cells with folate receptor alpha (FRα)-specific chimeric antigen receptors enhances their antitumor immunity toward FRα-positive ovarian cancers.

Folate receptor alpha (FRα) is aberrantly expressed in ovarian cancers but largely absent in normal tissues, and therefore represents an attractive target for immunotherapy. In recent years, modification of T cells with chimeric antigen receptor (CAR) targeting FRα has been reported to improve antitumor immunity of T cells. However, there are limited data regarding CAR-modified cytokine-induced killer (CAR-CIK) cells. In the present study, we modified CIK cells with FRα-specific CARs and investigated their antitumor immunity against ovarian cancers. We found that both non-transduced and mock CAR-transduced CIK cells showed only low antitumor activity against either FRα-positive (FRα+) or FRα-negative (FRα-) targets. However, all three generations of CAR-modified CIK cells showed enhanced antitumor activity against FRα+ targets, but not FRα- targets. First-generation ζ-CAR-CIK cells increased production of IFN-γ, enhanced short-term cytotoxicity against FRα+ ovarian cancer cells, and showed modest and short-term suppression of established tumors; while second-generation 28ζ- and third-generation 28BBζ-CAR-CIK cells showed significant proliferation, enhanced secretion of IL-2, eliminated the FRα+ ovarian cancer cells in long-term co-culture, and showed dramatic and long-term inhibition of tumor growth and prolonged survival of xenograft-bearing mice. It is noteworthy that the 28BBζ-CAR was more potent in the modification of CIK cells than 28ζ-CAR both in vitro and in vivo. Moreover, CAR-CIK cells showed more efficient anticancer activity compared with CAR-T cells in vitro, but less efficient than CAR-T cells in vivo. According to these results, we conclude that modification of CIK cells with FRα-specific CARs enhances their antitumor immunity to FRα+ ovarian cancers. The third-generation 28BB-ζ CAR containing 4-1BB co-stimulation was more efficient in modification of CIK cells than either first-generation ζ-CAR or second-generation CD28-ζ-CAR.

[Experiences of scarless laparoscopic radical resection of rectal cancer].

OBJECTIVE: To explore the feasibility and safety of scarless laparoscopic radical resection of rectal cancer. METHODS: Clinical data of 26 patients who underwent scarless laparoscopic radical resection of rectal cancer from January 2011 to June 2013 were retrospectively analyzed. Lymph node dissection and transection of proximal and distal colon were performed in the conventional manner of total mesorectal excision (TME). The distal rectum 2 cm away from the tumor was closed with a linear stapler, and was pulled out through the anus. The specimen was extracted through the Alexis. The rectal opening was reclosed with a linear stapler. End-to-end colorectal anastomosis was performed using the double-stapling technique. RESULTS: The operation time was (126±35) min. The intraoperative blood loss was (33±61) ml. The number of harvested lymph nodes was 17.0±5.6. The time to first bowel movement was (2.7±1.3) d. The postoperative hospital stay was (7.9±2.6) d. Only one case developed anastomotic hemorrhage. CONCLUSION: Scarless laparoscopic radical resection of rectal cancer is feasible.

Prevalence and molecular characterization of Cyclospora cayetanensis, Henan, China.

To determine prevalence of Cyclospora cayetanensis infection in Henan, China, we conducted a study of 11,554 hospital patients. Prevalence was 0.70% (95% confidence interval 0.70% ± 0.15%), with all age groups infected. Most cases were found in the summer. Minor sequence polymorphisms were observed in the 18S rRNA gene of 35 isolates characterized.

Genetic characterizations of Cryptosporidium spp. and Giardia duodenalis in humans in Henan, China.

Cryptosporidium and Giardia infections are common causes of diarrhea worldwide. To better understand the transmission of human cryptosporidiosis and giardiasis in Henan, China, 10 Cryptosporidium-positive specimens and 18 Giardia-positive specimens were characterized at the species/genotype and subtype levels. Cryptosporidium specimens were analyzed by DNA sequencing of the small subunit rRNA and 60kDa glycoprotein genes. Among those genotyped, nine belonged to C. hominis and one C. felis, with the former belonging to three subtype families: Ia, Ib, and Id. The three Ib subtypes identified, IbA16G2, IbA19G2, and IbA20G2, were very different from the two common Ib subtypes (IbA9G3 and IbA10G2) found in other areas of the world. The distribution of Giardia duodenalis genotypes and subtypes was assessed by sequence analysis of the triosephosphate isomerase (tpi) gene. The assemblages A (eight belonging to A-I and four A-II) and B (belonging to six new subtypes) were found in 12 and six specimens, respectively. More systematic studies are needed to understand the transmission of Cryptosporidium and G. duodenalis in humans in China.