Ligustroflavone mediates the resistance of non-small cell lung cancer to osimertinib by arresting G1/S phase / 药学学报

Natural products are an important source for the development of antitumor lead compounds, but the pharmacological effects and regulatory mechanisms of natural products in osimertinib resistance in non-small cell lung cancer (NSCLC) are not well understood. The natural product ligustroflavone was used as the research object to analyze its efficacy in osimertinib-resistant NSCLC cells by cell proliferation assay and cell cycle detection. The potential targets of ligustroflavone in osimertinib-resistant NSCLC cells were screened by public databases and bioinformatics, molecular docking and microscale thermophoresis were used to identify the interaction between privet and target molecules. Western blot was used to detect the effect of privet on the target molecules and their downstream pathways. Ligustroflavone reduced the proliferation of osimertinib-resistant NSCLC cells, and could arrest the cell cycle. Cyclin-dependent kinase 6 (CDK6) was the potential target of ligustroflavone in osimertinib-resistant NSCLC cells. Ligustroflavone inhibited the activation of CDK6-Rb axis. Together, ligustroflavone could regulate osimertinib resistance in NSCLC cells by binding cell cyclin-related molecules. This study provides a theoretical basis for the targeted drug resistance of NSCLC with natural products, and also provides a new idea for the development of clinical drug combination.

Celastrol inhibits PAK1 kinase and inhibits the proliferation of pancreatic cancer cells / 药学学报

The p21-activated kinase 1 (PAK1) is a member of the P21-activated protein kinase family that plays an important role in the proliferation and on cogenesis of pancreatic cancer. PAK1 is an important target for the treatment of pancreatic cancer. At present, akinase inhibitor targeting PAK1 is still in the preclinical research stage. Therefore, screening for new PAK1 kinase inhibitors is of great significance. In this study the natural compound celastrol was found to have a significant inhibitory effect on PAK1, with an IC50 value of 3.614 μmol·L-1. Molecular docking results showed that celastrol had good binding to PAK1. An MTT assay indicated that celastrol inhibited the proliferation of pancreatic cancer cells BxPC-3 and PANC-1. Mechanistic studies revealed that the inhibition of pancreatic cancer cells by celastrol was reversed by PAK1 siRNA. Celastrol inhibited PAK1 and the subsequent activation of downstream signaling pathways, thereby activating apoptosis signaling pathways and triggering apoptosis in pancreatic cancer cells. These findings suggested that celastrol induced apoptosis in pancreatic cancer cells by suppressing the PAK1 kinase signaling pathway and has potential value for the treatment of pancreatic cancer.

Establishment of zebrafish osteopenia model induced by dexamethasone / 药学学报

Zebrafish was selected as model animal, and glucocorticoid dexamethasone was used as a model compound to establish a rapid and high efficient osteopenia model. Zebrafish larvae at 4 days post fertilization (dpf) were exposed to a serial concentrations of dexamethasone solutions, and 0.5% DMSO was selected as the vehicle control group. All groups were incubated in 24-well plates (28.5 degrees C) until 9 dpf. In addition, effects of 10 micromol x L(-1) dexamethasone on preventing against osteopenia induced by etidronate disodium were also investigated. Zebrafish bones at 9 dpf were stained with alizarin red. Quantitative analysis of the stained area was performed by microscopic inspection and digital imaging methods to reflect the amount of bone mineralization. Results showed that dexamethasone group at 2.5, 10 and 25 micromol x L(-1) can decrease the staining area and the staining optical density values of zebrafish head bones when compared with the vehicle control group (0.5% DMSO), which suggested that dexamethasone can significantly reduce the zebrafish mineralized bone and the bone mineral density. Results also showed that 15 and 30 microg x mL(-1) etidronate disodium can increase the mineralized matrix of zebrafish head bone and prevent against osteopenia induced by dexamethasone. In conclusion, the study indicated that zebrafish can be an idea osteopenia model induced by dexamethasone.

Effect of rhGH on JAK2-STAT3 signal pathway after GHR was down-regulated by siRNA in gastric cancer cell / 药学学报

To investigate the effect of recombinant human growth hormone (rhGH) on JAK2-STAT3 pathway and the growth of gastric cancer cell lines at different GHR expression status, the eukaryotic expression vector targeting human GHR (pGPU6/GFP/Neo-shGHR and pGPU6/GFP/Neo-scramble) was constructed and transfected into MGC803 cells by Lipofectamine 2000. Stable expressive cell lines were obtained by G418 screening. The expression of GHR was analyzed by Western blotting. After being stimulated with rhGH, cell growth was detected by MTT assay. Cell cycle and apoptosis were examined by flow cytometry. The components of JAK2/STAT3 signaling pathway were detected by Western blotting. There is no significant difference of GHR expression between MGC803 and pGPU6/GFP/Neo-scramble-transfected cells (named as MGC803-NC) (P > 0.05). Compared with MGC803, the GHR expression in pGPU6/GFP/Neo-shGHR-transfected cells (named as MGC803-shGHR) decreased significantly (protein decreased 50%). The cells were treated with rhGH at 0, 150 and 300 ng x mL(-1), the growth rate of MGC803 and MGC803-NC increased significantly, PI and the number of G2/M phase cells all increased significantly, and apoptosis decreased significantly. Western blotting revealed that the expression of pJAK2 and pSTAT3 was up-regulated after being treated with rhGH in MGC803 and MGC803-NC cells. In contrast, similar change was not observed in MGC803-shGHR cells. Knockdown of GHR gene may decrease the sensitivity of gastric cancer cells to rhGH, and down-regulating of components of the expression of JAK2/STAT3 signaling pathway may be the potential mechanisms.

Monoclonal antibody: the corner stone of modern biotherapeutics / 药学学报

Worldwide sales of biologic drugs exceeded 100 billion USD in 2011. About 32% is from therapeutic monoclonal antibody (mAb). With many blockbuster biopharmaceutical patents expiring over the next decade, there is a great opportunity for biosimilar to enter the worldwide especially emerging market. Both European Medicines Agency (EMA) and Food and Drug Administration (FDA) have introduced regulatory frameworks for the potential approval of biosimilar mAb therapeutics. Rather than providing a highly abbreviated path, as in the case for small molecule chemical drug, approval for biosimilar mAb will require clinical trial and the details will be very much on a case-by-case basis. Since mAb is the dominant category of biologic drugs, mAb will be the focus of this review. First, the United States (US) and European Union (EU) approved mAb and those in phase 3 trials will be reviewed, then strategies on how to win biosimilar competition will be reviewed.

Construction and immunological analysis of a combined multi-epitope vaccine against EGFR/HER2 / 药学学报

A recombinant plasmid pET28a-HBcAg-delta n was constructed, in which three mimic B-epitopes of HER family were inserted into the truncated HBc vector. The fusion protein expressed was purified and used to immunize BALB/c mice to induce antibody against the epitopes. Three mimic epitope genes were inserted into the sequences of amino acid residues 78 and 79 of HBcAg by overlap PCR. The PCR product was then cloned into pET28a to construct recombinant expression plasmid which was transformed to E. coli BL21 (DE3) and induced by IPTG. After purification, the fused protein designed HBHE was used to immunize BALB/c mice to detect humoral immunoresponse. The recombinant plasmid was successfully constructed by DNA sequencing analysis. A fusion protein with correct molecular mass was expressed and confirmed by SDS-PAGE. High titre antibody was elicited in the mice immunized with HBHE by indirect ELISA and Western blotting. The HBc particle vector containing three B-epitopes of HER family had been successfully prepared, purified and high titre antibody against HBHE was detected. All these data are helpful in further research of the broad-spectrum anti-tumour effect of combine polypeptide epi-position vaccine of EGFR and HER2.