Increased amounts and stability of telomeric repeat-containing RNA (TERRA) following DNA damage induced by etoposide.

Telomeric repeat-containing RNAs (TERRAs) are long noncoding RNAs transcribed from subtelomeres toward telomeric repeat tracts, which have been implicated in telomere protection and heterochromatin formation. Genotoxic stress leads to upregulation of TERRAs. However, the mechanism of DNA damage-mediated TERRA induction remains elusive. Here, we treated HeLa cells with etoposide, a DNA double-strand break-generating agent, for various times and monitored the levels of TERRAs. Etoposide treatment led to a gradual time-dependent increase in TERRAs. Etoposide-mediated induction was evident in many TERRAs arising from various chromosome loci, including 20q and XpYp. Chromatin immunoprecipitation assays revealed no significant changes in the occupancy of RNA polymerase II at telomeres upon etoposide treatment. Interestingly, TERRAs arising from 20q, XpYp, 10q, and 13q degraded at slower rates in cells treated with etoposide, while degradation rates of TERRAs from many loci tested were nearly identical in both etoposide- and mock-treated cells. Telomere damage occurred from early time points of etoposide treatment, but telomere lengths and abundance of telomeric repeat-binding factor 2 (TRF2) at telomeres remained unchanged. In summary, etoposide treatment led to telomere damage and TERRA accumulation, but telomere lengths and TRF2-mediated telomere integrity were maintained. Etoposide-mediated TERRA accumulation could be attributed partly to RNA stabilization. These findings may provide insight into the post-transcriptional regulation of TERRAs in response to DNA damage

Growth inhibition by fusidic acid in cervical, thyroid, and breast carcinoma cell lines

Objective We investigated the effects of fusidic acid (FA) on human cervical, thyroid, and breast carcinoma cell lines to determine the potential usefulness of FA in cancer treatment. Methods Six cancer cell lines (cervical cancer: Caski, HeLa; thyroid cancer: 8505C, TPC1; and breast cancer: MCF-7, MDA-MB-231) were treated with FA. Furthermore the changes in cell growth, cell cycle duration, and extent of apoptosis were analyzed. Results After FA treatment, the cancer cells showed a decrease in growth rate. In the cell death assay, the cell populations were similar in each cell type after treatment with FA, indicating that growth inhibition by FA was not related to the induction of apoptosis. FA induced cell cycle arrest at a dose that inhibited growth rate, which varied in different cell types. G0/G1 phase arrest occurs in breast cancer, S phase arrest in 8505C thyroid cancer, and G2/M phase arrest in cervical cancer. These results indicate that FA reduces growth rates by inducing cell cycle arrest. Conclusion FA treatment can interfere with cell proliferation by inducing cell cycle arrest in human cervical, thyroid, and breast carcinoma cell lines. Thus, FA can be useful in treating human cervical, thyroid, and breast carcinomas

Coexisting ovarian and tubal pregnancies on opposite sides after intrauterine insemination: a case report

Abstract Background Ovarian pregnancy is very rare, and contralateral tubal pregnancy coexisting with ovarian pregnancy must be even rarer. Case presentation A 33-year-old Korean nulliparous woman was referred to our hospital because she suffered lower abdominal pain and had missed her periods after controlled ovarian hyperstimulation and intrauterine insemination. We could not identify any normal gestational sac in the endometrium, or specific ectopic pregnancies, on an initial ultrasound scan. However, there was a large hematoma in the cul-de-sac and free fluid in the right paracolic gutter. We decided to perform emergent laparoscopic surgery. We found contralateral tubal and ovarian ectopic pregnancies. Conclusion To the best of our knowledge, this is the first report of a case in which a patient underwent laparoscopic right salpingectomy and left ovarian ectopic mass excision due to contralateral tubal and ovarian ectopic pregnancies after assisted reproductive technology

Additional file 1: of Coexisting ovarian and tubal pregnancies on opposite sides after intrauterine insemination: a case report

Timeline of treatment. This figure shows timeline of treatment for this case. (PDF 123 kb) (PDF 122 kb