Current status and future prospect of pharmacotherapy for pancreatic cancer / 中国中药杂志

Pancreatic cancer is the most common digestive tract tumor with an increasing incidence in recent years. The poor prognosis of pancreatic cancer is mainly because of the inability of detecting tumor at an early stage,its high potential for early dissemination,and its relatively poor sensitivity to chemotherapy. Most patients have lost the opportunity for surgery when they are diagnosed,which resulted in an urgent need for the development of more effective and safe therapies for pancreatic cancer. However,the current clinical cancer chemotherapy based on gemcitabine leads to poor prognosis in pancreatic patients. With the continuous research on the biological and cellular signaling pathways of pancreatic cancer,there have emerged a great many of novel agents,including new chemotherapeutic,targetable and immune-modulatory drugs,and some drugs have achieved encouraging results. Furthermore,as an alternative and supplementary method,traditional Chinese medicine has shown good application prospects in the field of pancreatic cancer treatment. This article reviews the current status of drug therapy for pancreatic cancer,summarizes the strength and weakness of existing therapeutic drugs in the application process,gives prospects of possible breakthroughs for the pharmacotherapy in the future,and provides certain new ideas and lessons for subsequent drug development.

Inhibitory effect and mechanism of platycodin D combined with imatinib on K562/R / 中国中药杂志

Platycodin D(PD) has a significantly inhibitory effect on multiple malignant tumors, and can inhibit the proliferation of leukemia cells K562 and induce apoptosis. However, its effect in improving the sensitivity of drug-resistant cells to imatinib and their molecular mechanism remained unclear. To investigate the effect and mechanism of PD alone or combined with imatinib (IM) in inhibiting CML imatinib resistant cell line K562/R, the cell proliferation was examined by CCK8 assay to reveal the effect of PD on the inhibitory function of imatinib. Cell apoptosis was detected by Annexin V-FITC/PI double staining. Protein expressions of cleaved caspase-3, cleaved caspase-9, PARP, cleaved PARP, Bcr/abl, p-AKT and p-mTOR were detected by Western blot. The results showed that the inhibitory effect of PD combined with imatinib on the proliferation and apoptosis of K562/R cells was significantly higher than that of the control group and the single drug group. Protein expressions of cleaved caspase-3, cleaved caspase-9 and cleaved PARP were significantly up-regulated in the combination group, and protein expressions of PARP, Bcr/abl, p-AKT and p-mTOR were down-regulated. The results indicated that PD increased the sensitivity of drug-resistant cells to imatinib, and the inhibitory effect of PD combined with imatinib was significantly better than the single drug on cell proliferation, induction of apoptosis, inhibition of Bcr/abl protein and PI3K/AKT/mTOR signaling pathway.

Inhibition of dihydrotanshinone on migration and invasion of gastric cancer SGC7901 cells and its mechanism / 中草药

Objective: To study the effects of dihydrotanshinone (DHT) on the migration and invasion of human gastric cancer SGC7901 cells and to investigate its mechanism. Methods: SGC7901 cells were treated with different concentration of DHT. Then, the inhibitory effect of DHT was detected by MTT assay. The scratch adhesion test and Transwell assay were performed to determine the migration and invasion capacity of the cells. Quantitative PCR and Western boltting were used to examine the expression of MMP2, MMP9, Gli1, and HHIP in SGC7901 cells. Results: DHT could inhibit the proliferation of SGC7901 cells with obvious dose- and time- dependent effects. DHT significantly inhibited the migration and invasion ability in SGC7901 cells in vitro. The expression of MMP9 was obviously down-regulated after DHT treatment. Furthermore, DHT significantly inhibited the Gli1 mRNA and proteins expression levels, and evaluated the expression of HHIP in SGC7901 cells. Conclusion: DHT could inhibit the capability of migration and invasion of human gastric cancer SGC7901 cells. The potential molecular mechanism may be related to the inhibition of MMP9, and down-regulation of Hedgehog signaling pathway.

Progress of regulation of leukemia stem cells of chronic myeloid leukemia by autophagy / 中国中药杂志

Leukemia stem cells (LSC) that were found in chronic myeloid leukemia (CML) responsible for the abnormal proliferation with the potential of self-renewal and multi-directional differentiation are involved in the pathophysiological process for drug resistance and relapse of CML. Autophagy, a conservative lysosomal degradation process that mediates cell degradation and recycling process, plays crucial roles in maintaining the homeostasis and function of intracellular environment. Recent studies suggested that autophagy is involved in the regulation of LSC differentiation and also closely related to the chemo-sensitivity of CML. In this review, we focused on the role of autophagy on chemotherapy sensitivity of CML as well as the leukemia stem cell function for the development of new anti-leukemia drugs.

Effect of cryptotanshinone on imatinib sensitivity and P-glycoprotein expression of chronic myeloid leukemia cells / 中国中药杂志

Cryptotanshinone (CPT), a lipid soluble active compound in Salvia miltiorrhiza, has a significant inhibitory effect on multiple malignant tumors, e. g. chronic myeloid leukemia (CML) cells and can effectively enhance imatinib's chemotherapeutic effect. However, its functional molecular mechanism remained unclear. In this experiment, the authors conducted a systematic study on the effect of CPT on the imatinib sensitivity and P-glycoprotein (P-gp) expression in CML cells by using CML cells K562 and imatinib persister K562-R. The MTT assays were performed to determine CPT's impact on the inhibitory effect of imatinib. Annexin V-FITC/PI staining analysis was used to detect the changes in the cell apoptosis rate. The active changes in apoptosis regulatory proteins Caspase-3, Caspase-9 and PARP were determined by Western blot. After the cells were pretreated with the gradient concentration of CPT, the expression of P-gp was analyzed by Western blot and flow cytometry. The changes in intracellular concentrations of imatinib were determined by HPLC analysis. The results indicated that the pretreatment with CPT significantly increased the proliferation inhibiting and apoptosis inducing effects of imatinib on K562 and K562-R cells as well as the degradation product expression of pro-apoptotic proteins Caspase-3, Caspase-9 and PARP, with a significant difference with the control group (P < 0.01). However, CPT showed no impact on the P-gp expression in CML cells and the intracellular concentrations of imatinib. In summary, the findings suggested that CPT enhanced the sensitivity of CML cells to imatinib. Its mechanism is not dependent on the inhibition in P-gp expression and the increase in intracellular drug concentration.

Effect of cryptotanshinone on apoptosis in K562 cell and its mechanism / 中草药

Objective: To investigate the apoptosis inducing effects of cryptotanshinone (CPT) in human chronic myeloid leukemia K562 cells and its molecular mechanisms. Methods: K562 cells were firstly treated with CPT at different concentration. Then, the inhibitory effect of CPT was detected by MTT assay; morphological changes of cells were observed by inverted microscope; cell apoptosis was detected by Annexin V-FITC/PI staining. Western blotting was carried out to determine the expression of apoptosis-related proteins, including Caspase-3, Caspase-9, PARP, Bax, Bcl-2 and cytochrome C (Cyt C). The mitochondrial membrane potential was measured using JC-1 probe. Finally, the effects of CPT on the proliferation and apoptosis were detected in the absence or presence of inhibitors for mitochondrial permeability transition pore (PTP) and caspase-family. Results: CPT significantly inhibited the proliferation, induced apoptosis and morphological changes of K562 cells. Furthermore, CPT increased the Bax/Bcl-2 ratio obviously, decreased the mitochondrial membrane potential, and enhanced the Cyt C release. CPT also significantly increased the activities of pro-apoptotic proteins, such as Caspase-3, Caspase-9, and PARP. The inhibitors of PTP and caspase-family reduced the pharmacodynamics of CPT obviously. Conclusion: These results show that CPT could significantly induce the apoptosis of human chronic myeloid leukemia cells, in which its function is related with the mitochondrial pathway.

Mechanism of platycodin D-induced apoptosis in A549 human lung cancer cells / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the molecular mechanism of platycodin D showing the inhibitory effect on proliferation and induced apoptosis of humane long cancer cells A549.</p><p><b>METHOD</b>Humane long cancer cells A549 were cultured in vitro, with the final PD concentration of 5-20 micromol x L(-1). PD's inhibitory effect on cell proliferation was examined by MTT assay. Morphological changes in cells were observed with microscope. The cell apoptosis rate was detected by Annexin V-FITC/PI double staining. The change of mitochondrial membrane potential was detected by JC-1. The protein expressing of leaved Caspase-3, cleaved Caspase-9, cleaved PARP, Bcl-2, Bcl-xl, Bak and Bax were detected by Western blot analysis.</p><p><b>RESULT</b>PD could inhibit the proliferation of A549 cells and show stronger effect with the increase of concentration and over time. Compared with the control group, PDs of different concentration showed significant increase in the cell apoptosis rate, decrease in mitochondrial membrane potential after 24 h. Protein electrophoresis inspection showed cut segments in both protein Caspase-3 and Caspase-9 and notable fractures with time. Further study found that PD decreased Bcl-2, Bcl-xl proteins and increased Bax, Bak proteins after processing A549 cells.</p><p><b>CONCLUSION</b>PD shows notable effect on cytotoxicity and can induce A549 cell apoptosis. It causes decrease in mitochondrial membrane potential by regulating Bax, Bak, Bcl-2 and Bcl-xl expressions, and thus activating caspase and finally causing long cancer cell apoptosis.</p>

In vitro MR imaging of Fe2O3-arginine labeled heNOS gene modified endothelial progenitor cells / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the feasibility of in vitro magnetic resonance imaging on Fe2O3-arginine labeled heNOS gene modified endothelial progenitor cells (EPCs).</p><p><b>METHODS</b>Fe2O3 was incubated with arginine to form Fe2O3-arginine complex. Rabbit peripheral blood mononuclear cells (MNCs) were isolated and EPCs were isolated by adherence method, expanded and modified with heNOS gene using Lipofectamine 2000. After 48 hours, genetically modified EPCs were incubated with Fe2O3-arginine for 24 hours. Intracellular iron was detected by Prussian blue stain. The expression of heNOS gene was detected by Western blot. MTT assay was used to evaluate cell survival and proliferation of Fe2O3-arginine labeled heNOS-EPCs. Flow cytometry was used to measure cell apoptosis. The cells underwent in vitro MR imaging with various sequences.</p><p><b>RESULTS</b>Iron-containing intracytoplasmatic vesicles could be clearly observed with Prussian blue staining, and the labeling rate of labeled heNOS-EPCs were similar to that of labeled EPCs (around 100%). Survival and apoptosis rates obtained by MTT and flow cytometry analysis were similar among labeled heNOS-EPCs, labeled EPCs and unlabeled EPCs with Fe2O3-arginine. The signal intensity on MRI was equally decreased in labeled heNOS-EPCs and labeled EPCs compared with that in unlabeled cells. The percentage change in signal intensity (DeltaSI) was most significant on T2*WI and DeltaSI was significantly lower in cells labeled for 7 days than that labeled for 1 days.</p><p><b>CONCLUSIONS</b>The heNOS gene can be successfully transfected into rabbit peripheral blood EPCs using Lipofectamine2000. The heNOS-EPCs can be labeled with Fe2O3-arginine without significant change in viability and proliferation capacity. The labeled heNOS-EPCs can be imaged with standard 1.5 T MR equipment. The degree of MR signal intensity may indirectly reflect the cell count, growth and division status.</p>

Promoting Effect of N-Acetylglucosaminyltransferase Ⅱ on the Migration of Mouse Breast Cancer Cell / 中国生物工程杂志

It is well documented that altered biosynthesis of cell surface N-linked oligosaccharides is associated with the transformed cells and tumors.N-acetylglucosaminyltransferase Ⅱ(GnT-II;EC 2.4.1.143)is a medial Golgi enzyme that catalyses the incorporation of a GlcNAc residue in ?-1,2 linkage to the Man-?-1,6 arm of the N-glycan core.This is an essential step in the biosynthetic pathway leading from hybrid to complex N-glycans.Because functional GnT-Ⅱ is an prerequisite of N-Acetylglucosaminyltransferase V performance,It was speculated that GnT-Ⅱ was involved in cancer development and progression.The expression of GnT-Ⅱ in mouse breast cancer cells 67NR and 4T1 which have different behavior of metastasis was analysed using RT-PCR.The amounts of GnT-Ⅱ in the highly metastatic cell 4T1 increased to 1.53 times of the lowly metastatic cell 67NR.To determine the association of GnT-Ⅱ with tumor progression,the GnT-Ⅱ encoding gene was amplified with RT-PCR and cloned into retrovirus vector pMSCV,resulting in pMSCV-GnT-Ⅱ.The recombinant plasmid was transfected into 4T1 and the transfected cells were selected in the medium containing puromycin,which were harvested to detect the adhesion ability to fibronection and the migration potential by transwell system.The cell adhesion to fibronectin was weakened by 67% and migration potential was increased by 82%.The data indicates that GnT-Ⅱ mediates cell adhesion and migration,thus may play an important role in cancer metastasis.