LINC00094/miR-19a-3p/CYP19A1 axis affects the sensitivity of ER positive breast cancer cells to Letrozole through EMT pathway.

The endocrine therapy resistance of breast cancer is the difficulty and challenge to be urgently solved in the current treatment. In this study, we examined the effects of noncoding RNA LINC00094 and miR-19a-3p on breast cancer in vivo and in vitro by RT-QPCR, Western Blot, luciferase assay, immunofluorescence and drug sensitivity tests. The plasma level of CYP19A1 in patients with breast cancer resistance was lower than that in drug sensitive patients. Compared with normal subjects, miR-19a-3p was highly expressed in plasma of patients with breast cancer. miR-19a-3p is highly expressed in estrogen receptor positive breast cancer cells. The expression of miR-19a-3p promoted the migration and EMT of breast cancer cells and reduced the sensitivity of breast cancer to Letrozole. LINC00094 sponge adsorbed miR-19a-3p. LINC00094 promotes the expression of CYP19A1, the target gene of miR-19a-3p, and inhibits the EMT process of breast cancer, ultimately promoting the sensitivity of ER-positive breast cancer cells to Letrozole. This study found a new mechanism of Letrozole sensitivity in ER positive breast cancer.

TDO2 modulates liver cancer cell migration and invasion via the Wnt5a pathway.

Liver cancer is a malignant cancer phenotype for which there currently remains a lack of reliable biomarkers and therapeutic targets for disease management. Tryptophan 2,3­dioxygenase (TDO2), a heme­containing polyoxygenase enzyme, is primarily expressed in cells of the liver and nervous systems. In the present study, through the combination of cancer bioinformatics and analysis of clinical patient samples, it was shown that TDO2 expression in liver cancer tissue samples was significantly higher than that in normal tissues, and liver cancer patients with high TDO2 expression had a poor prognosis. Mechanistic studies on liver cancer cells showed that TDO2 promoted cancer cell migration and invasion via signal transduction through the Wnt5a pathway. Such regulation impacted the expression of cancer­associated biomarkers, such as matrix metalloprotease 7 (MMP7) and the cell adhesion receptor CD44. Treatment with a calcium channel blocker (azelnidipine) reduced TDO2 levels and inhibited liver cancer cell migration and invasion. A mouse xenograft cancer model showed that TDO2 promoted tumorigenesis. Furthermore, azelnidipine treatment to downregulate TDO2 also decreased liver cancer development in this mouse cancer model. TDO2 is thus not only a useful liver cancer biomarker but a potential drug target for management of liver cancer.

A rare case report of waldenström macroglobulinemia converted to serum low IgM.

Waldenström Macroglobulinemia (WM) is a rare chronic lymphoproliferative disease, accounting for less than 2% of hematological malignancies. It is characterized by plasma cytoid lymphocyte infiltration in bone marrow and abnormal increase of monoclonal IgM in peripheral blood. Only 5%-10% of cases of WM secrete monoclonal IgG and IgA components or do not secrete monoclonal long immunoglobulin. This case is the first to report of serum protein recombination from lgM and Igkappa band mutation to abnormal lgG and Igkappa band after 6 years of treatment in a male patient with WM.

Demethylation of the MIR145 promoter suppresses migration and invasion in breast cancer.

miR-145 has been implicated in the progression of breast cancer. Here, we report that its expression is decreased in breast cancer specimens and cell lines and that this low level of expression is associated with DNA methylation of its gene, MIR145. Methylation of MIR145 has previously been correlated with cell migration and invasion, both in vivo and in vitro. We found that demethylation of MIR145 reactivates miR-145 and contributes to the anti-cancer properties of 5-aza-2'-deoxyazacytidine (5-AzaC). Therefore, miR-145 is a potentially valuable biomarker for breast cancer.

microRNA-218 expression and its association with the clinicopathological characteristics of patients with cervical cancer.

The aim of the present study was to investigate the expression of microRNA-218 (miRNA-218) in the serum and cervical tissue and its association with the clinicopathological features of cervical cancer (CC). The expression of miRNA-218 was detected in the serum and cervical tissue of 112 patients with CC and 50 age-matched hysteromyoma patients via the reverse transcription-quantitative polymerase chain reaction. The clinical data were collected and the association between the expression of miRNA-218 and the clinicopathological characteristics of the patients was analyzed. The expression of miRNA-218 in the cancer group was significantly decreased in the cervical tissue and serum compared with that in the control group (P<0.001). The decreased expression of miRNA-218 was associated with a later International Federation of Gynecology and Obstetrics stage, a more invasive pathological type and lymphatic node metastasis but not with age, age at menarche, menopausal status, number of pregnancies and deliveries, family history of cancer or tumor size. In conclusion, miRNA-218 was found to be downregulated in the cancer tissue and serum of the patients with CC. The decreased expression of miRNA-218 in CC was associated with the invasiveness of the tumor.

DNAzymes targeted to EBV-encoded latent membrane protein-1 induce apoptosis and enhance radiosensitivity in nasopharyngeal carcinoma.

Epstein-Barr virus (EBV) is involved in the carcinogenesis of several types of cancers such as nasopharyngeal carcinoma (NPC) and Burkitt's lymphoma. The latent membrane protein (LMP1) encoded by EBV is expressed in the majority of EBV-associated human malignancies and has been suggested to be one of the major oncogenic factors in EBV-mediated carcinogenesis. Therefore, genetic manipulation of LMP1 expression may provide a novel strategy for the treatment of the EBV-associated human cancers. Deoxyribozymes (DNAzymes) are catalytic nucleic acids that bind and cleave a target RNA in a highly sequence-specific manner. We have designed several LMP1-specific DNAzymes and tested their effect on cell proliferation and apoptosis in LMP1-positive cells. Here, we show that active DNAzymes down-regulated the expression of the EBV oncoprotein LMP1 and inhibited cellular signal transduction pathways abnormally activated by LMP1. This down-regulation of the LMP1 expression was shown to be associated with a decrease in the level of antiapoptotic Bcl-2 and an increase in Caspase-3 and -9 activities in the nasopharyngeal carcinoma cell line CNE1-LMP1, which constitutively expresses the LMP1. When combined with radiation treatment, the DNAzymes significantly induced apoptosis in CNE1-LMP1 cells, leading to an increased radiosensitivity both in cells and in a xenograft NPC model in mice. The results suggest that LMP1 may represent a molecular target for DNAzymes and provide a basis for the use of the LMP1 DNAzymes as potential radiosensitizers for treatment of the EBV-associated carcinomas.

Phosphorylation and nuclear translocation of STAT3 regulated by the Epstein-Barr virus latent membrane protein 1 in nasopharyngeal carcinoma.

The Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) oncoprotein has been shown to mediate activation of the signal transducer and activator of transcription 3 (STAT3). In the present study, we delineated the mechanism by which LMP1 stimulates STAT3 in a human nasopharyngeal carcinoma (NPC) cell line. LMP1 stimulated STAT3 Tyr 705-dependent nuclear accumulation, as well as the phosphorylation of STAT3 at both Tyr 705 and Ser 727. Treatment of cells with interleukin-6 neutralizing antibody inhibited the phosphorylation of STAT3 Tyr 705 and Ser 727. The differential phosphorylation of STAT3 was found to be a result of activation of Janus kinase 3 (JAK3) and extracellular signal-regulated kinase (ERK). The biological significance of JAK3-mediated activation of STAT3 Tyr 705 phosphorylation was further assessed by treating the cells with an inhibitor (WHI-P131) of JAK3. Inhibition of ERK activity by an inhibitor (PD98059) of MAPK/extracellular signal-regulated kinase kinase (MEK1) decreased the LMP1-induced activation of STAT3 Ser 727. Furthermore, immunohistochemical analysis showed an increased nuclear STAT3 Tyr 705 staining in LMP1-positive cells and STAT3 Tyr 705 phosphorylation related to NPC stages III and IV. Demonstration of the involvement of different kinases in LMP1-induced STAT3 activation supports the involvement of the JAK/STAT and mitogen-activated protein kinase (MAPK)/ERK signaling pathways in the regulation of STAT3 activation by LMP1.

Grifolin, a potential antitumor natural product from the mushroom Albatrellus confluens, inhibits tumor cell growth by inducing apoptosis in vitro.

Grifolin is a natural biologically active substance isolated from the fresh fruiting bodies of the mushroom Albatrellus confluens. Here, for the first time, we describe a novel activity of grifolin, namely its ability to inhibit the growth of tumor cells by the induction of apoptosis. Grifolin strongly inhibited the growth of tumor cell lines: CNE1, HeLa, MCF7, SW480, K562, Raji and B95-8. Analysis of acridine orange (AO)/ethidium bromide (EB) staining and flow cytometry showed that grifolin possessed apoptosis induction activity to CNE1, HeLa, MCF7 and SW480. Furthermore, the cytochrome c release from mitochondria was detected by confocal microscopy in CNE1 cells after a 12h treatment with grifolin. The increase of caspase-8, 9, 3 activities revealed that caspase was a key mediator of the apoptotic pathway induced by grifolin, and the underexpression of Bcl-2 and up-regulation of Bax resulted in the increase of Bax: Bcl-2 ratio, suggesting that Bcl-2 family involved in the control of apoptosis. Owing to the combination of the significant antitumor activity by inducing apoptosis and natural abundance of the compound, grifolin holds the promise of being an interesting antitumor agent that deserves further laboratory and in vivo exploration.

Effect of EBV LMP1 targeted DNAzymes on cell proliferation and apoptosis.

The latent membrane protein (LMP1) encoded by Epstein-Barr virus (EBV) has been suggested to be one of the major oncogenic factors in EBV-mediated carcinogenesis. RNA-cleaving DNA enzymes are catalytic nucleic acids that bind and cleave a target RNA in a highly sequence-specific manner. In this study, we explore the potential of using DNAzymes as a therapeutic approach to EBV-associated carcinomas by targeting the LMP1 gene. In all, 13 different phosphorothioate-modified "10-23" deoxyribozymes (DNAzymes) were designed and synthesized against the LMP1 mRNA and transfected into B95-8 cells, which constitutively express the LMP1. Fluorescence microscopy was used to examine the cellular uptake and distribution in B95-8 cells. As demonstrated in Western blots, three out of 13 deoxyribozymes significantly downregulated the expression of LMP1 in B95-8 cells. These DNAzymes were shown to markedly inhibit B95-8 cell growth compared with a disabled DNAzyme and untreated controls, as determined by an alamarBlue Assay. It was further demonstrated that these DNAzymes arrested the B95-8 cells in G0/G1 using flow cytometry. Interestingly, the active DNAzymes could also downregulate the expression of Bcl-2 gene in treated cells, suggesting a close association between the LMP1 and Bcl-2 genes and their involvement in apoptosis. This was further confirmed with the result that the DNAzymes could induce the release of cytochrome c from mitochondria, which is the hallmark of the apoptosis. The present results suggest that the LMP1 may present a potential target for DNAzymes towards the EBV-associated carcinoma through cell proliferation and apoptosis pathways.