Antitumor activity of miR-188-3p in gastric cancer is achieved by targeting CBL expression and inactivating the AKT/mTOR signaling.

BACKGROUND: Altered miR-188-3p expression has been observed in various human cancers. AIM: To investigate the miR-188-3p expression, its roles, and underlying molecular events in gastric cancer. METHODS: Fifty gastric cancer and paired normal tissues were collected to analyze miR-188-3p and CBL expression. Normal and gastric cancer cells were used to manipulate miR-188-3p and CBL expression through different assays. The relationship between miR-188-3p and CBL was predicted bioinformatically and confirmed using a luciferase gene reporter assay. A Kaplan-Meier analysis was used to associate miR-188-3p or CBL expression with patient survival. A nude mouse tumor cell xenograft assay was used to confirm the in vitro data. RESULTS: MiR-188-3p was found to be lower in the plasma of gastric cancer patients, tissues, and cell lines compared to their healthy counterparts. It was associated with overall survival of gastric cancer patients (P < 0.001), tumor differentiation (P < 0.001), lymph node metastasis (P = 0.033), tumor node metastasis stage (I/II vs III/IV, P = 0.024), and American Joint Committee on Cancer stage (I/II vs III/IV, P = 0.03). Transfection with miR-188-3p mimics reduced tumor cell growth and invasion while inducing apoptosis and autophagy. CBL was identified as a direct target of miR-188-3p, with its expression antagonizing the effects of miR-188-3p on gastric cancer (GC) cell proliferation by inducing tumor cell apoptosis and autophagy through the inactivation of the Akt/mTOR signaling pathway. The in vivo data confirmed antitumor activity via CBL downregulation in gastric cancer. CONCLUSION: The current data provides ex vivo, in vitro, and in vivo evidence that miR-188-3p acts as a tumor suppressor gene or possesses antitumor activity in GC.

DNA barcoding reveals CITES-listed species among Taiwanese government-seized chelonian specimens.

Compared to traditional morphological identification, DNA barcoding-molecular identification based on sequencing of a segment of mitochondrial cytochrome c oxidase subunit I (COI)-provides a shortcut to authenticating chelonian identifications. Here, we selected 63 government-seized chelonian specimens deposited at Taipei Zoo for DNA barcoding analysis. DNA barcoding and subsequent phylogenetic analysis successfully authenticated 36 chelonian species, including five that are listed in CITES Appendix I. Approximately 90% (57/63) of the specimens were successfully authenticated by our molecular approach, but lack or error of BOLD reference sequences, biological processes such as hybridization, and uncertain species delimitation all reduced the accuracy of DNA barcoding. To increase the accuracy of DNA barcoding, Taipei Zoo will continue to enrich the BOLD database and also establish a genetic database, to include additional genetic markers, by using government-seized chelonian specimens. A fast and accurate method to authenticate seized samples could assist law enforcement agencies to prosecute criminals and restrict illegal exploitation of wild chelonian resources.