Experimental study of the function and mechanism combining dihydroartemisinin and gemcitabine in treating pancreatic cancer / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the anti-tumor activity of combined gemcitabine with dihydroartemisinin, and the mechanism of the anti-tumor effect of gemcitabine enhanced by dihydroartemisinin on pancreatic cancer.</p><p><b>METHODS</b>For cultured cells, cell growth was determined by the MTT assay and apoptosis was evaluated by flow cytometry analysis and confocal laser scanning microscope stained with Annexin V-FITC/PI. The nuclear extract for determining NF-kappaB DNA-binding activity was analyzed by EMSA, while nuclear P65 and its downstream gene expression was determined by Western blot assay. BxPC-3 cells were injected subcutaneously into nude mice to establish pancreatic xenograft tumors and the tumor volume was monitored after exposure to agents. TUNEL assay was used to assess tumor cell apoptosis in tumor tissue.</p><p><b>RESULTS</b>After combination of gemcitabine and dihydroartemisinin treatment, the proliferative inhibition rates of pancreatic cancer cells BxPC-3 and Panc-1 reached up to (81.1 +/- 3.9)% and (76.5 +/- 3.3)%, and the apoptosis rates were up to (53.6 +/- 3.8)% and (48.3 +/- 4.3)%, the differences were significantly (P < 0.01) compared with gemcitabine [(24.8 +/- 2.9)% and (21.8 +/- 3.5)%]. All the treatment groups inhibited the growth of pancreatic xenograft tumors in nude mice. The tumor volume and apoptosis index were (262 +/- 37) mm(3) and (50 +/- 4)% respectively in the combined treatment, compared to those of [(384 +/- 56) mm(3) and (25 +/- 3)%] in gemcitabine, the differences were significantly (P < 0.05). EMSA showed that gemcitabine alone obviously enhanced its DNA-binding activity compared to control. However, dihydroartemisinin significantly reduced its DNA-binding activity, so that abrogated the inducing effect of gemcitabine on NF-kappaB activation. Western blot assay indicated that dihydroartemisinin downregulated expression of nuclear P65, and combined treatment not only downregulated the expression of Cyclin D1, Bcl-xL and Bcl-2 while upregulated Bax, thus reduced the Bcl-2/Bax ratio, but also increased the caspase-3 activation, all of which increased apoptosis in both BxPC-3 and Panc-1 cells.</p><p><b>CONCLUSION</b>Dihydroartemisinin significantly abrogated the inducing effect of gemcitabine on NF-kappaB activation and downregulated the expression of NF-kappaB targeted gene products, which may be one possible mechanism by which dihydroartemisinin augments the anti-tumor effect of gemcitabine on pancreatic cancer.</p>

Protection of CSE/H2S system in hepatic ischemia reperfusion injury in rats / 中华外科杂志

<p><b>OBJECTIVE</b>To study the protective function and pathophysiology of cystathionine gamma-lyase (CSE)/hydrogen sulfide (H(2)S) system in hepatic ischemia-reperfusion injury (HIRI) in rats.</p><p><b>METHODS</b>Wistar rats were randomly distributed into sham group (n = 18), ischemia-reperfusion (IR) group (n = 18), IR + NaHS group (n = 18) and IR + DL-propargylglycine (PAG) group (n = 18). The hepatic IR model was established by Pringle's hepatic vascular occlusion. At each of the indicated time points (1, 3 and 6 hours after IR), the serum levels of H(2)S and the hepatic CSE activity were measured. The serum levels of inflammatory factors, including TNF-α, IL-10 were determined by ELISA methods. The expression of apoptotic protein, TNF-α, in liver tissue was tested by Western blot assay, cell apoptosis was examined by TUNEL and the histological changes were examined in each group.</p><p><b>RESULTS</b>The serum levels of H(2)S and CSE activity were significantly increased in group IR compared with group sham at all indicated time points (P < 0.05). The serum level of inflammatory factors (P < 0.01) and the hepatic expression of TNF-α protein (P < 0.05) were elevated obviously in group IR than that in group sham. Administration of NaHS could reduce the production of inflammatory factors in serum (P < 0.01), inhibit hepatic protein expression of TNF-α (P < 0.05) and attenuate the liver histological scores of IR injury (P < 0.05), whereas PAG aggravated them.</p><p><b>CONCLUSION</b>The endogenous CSE/H(2)S system maybe involved in the pathogenesis of hepatic IR injury, which suggests that CSE/H(2)S system can protect liver from IR injury in rats by intervening in inflammatory reaction, attenuating the injury severity and inhibiting expression of apoptotic protein TNF-α.</p>

An experimental study of gemcitabine inducing pancreatic cancer cell apoptosis potentiated by nuclear factor-kappa B P65 siRNA / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the effect and mechanism of NF-kappaB P65 gene silencing by small interference RNA on the apoptosis of human pancreatic cancer cells induced by gemcitabine in vitro and in vivo.</p><p><b>METHODS</b>Human pancreatic cancer cells (BxPC-3 and PANC-1) were cultured and respectively divided into five groups: blank control group, negative control siRNA group, gemcitabine group, NF-kappaB P65 siRNA group and gemcitabine + P65 siRNA group. The ability of cell proliferation was analyzed by MTT; the expression of NF-kappaB P65 and the apoptosis related proteins were examined by Western blot assay; the apoptosis was evaluated by the flow cytometry and laser scanning confocal microscopy analysis stained with Annexin V-FITC/PI; the DNA binding activity of NF-kappaB was examined by electrophoretic mobility shift assay. BxPC-3 cells were injected subcutaneously into nude mice to establish pancreatic xenograft tumors. The tumor volume was monitored and TUNEL assay was used to assess the apoptosis index in tumor tissue after treatment.</p><p><b>RESULTS</b>At 72 h after transfection, the combination with gemcitabine and p65 siRNA significantly decreased the cell viability index (P < 0.05), and down-regulated the expression of Bcl-2 and procaspase-3 and up-regulated the expression of Bax compared with other groups. The combined treatment significantly increased the rate of apoptosis compared with other groups (P < 0.05). EMSA assay indicated that the DNA binding activity of NF-kappaB significantly decreased in NF-kappaB P65 siRNA group and gemcitabine+P65 siRNA group compared with Control group. The combined therapy inhibited the growth of pancreatic xenograft tumors by apoptosis induction in nude mice (P < 0.01).</p><p><b>CONCLUSIONS</b>The effect of gemcitabine inducing cell apoptosis may be potentiated through inhibiting the DNA binding activity of NF-kappaB and regulating the expression of apoptosis related proteins by NF-kappaB P65 siRNA, which can activate the mitochondria apoptosis pathway in pancreatic cancer in vitro and in vivo.</p>

Study on anticancer effect of dihydroartemisinin on pancreatic cancer / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the anti-tumor activity of dihydroartemisinin in pancreatic cancer in vitro and in vivo.</p><p><b>METHODS</b>For cultured cells, cell growth was determined by the MTT assay and apoptosis was evaluated by flow cytometry analysis stained with Annexin V-FITC/PI. The protein expression in BxPC-3 cells was analyzed by Western blot assay. BxPC-3 cells were injected subcutaneously into nude mice to establish pancreatic xenograft tumors and the tumor volume was monitored after exposure to dihydroartemisinin. Ki-67 staining and TUNEL assay were used to assess tumor cell proliferation and apoptosis in tumor tissue.</p><p><b>RESULTS</b>After treatment by dihydroartemisinin in vitro, the proliferative inhibition rates of pancreatic cancer cells BxPC-3 and AsPC-1 reached up to (76.2 +/- 3.5)% and (79.5 +/- 2.9)%, and the apoptosis rates were up to (55.5 +/- 3.2)% and (40.0 +/- 3.5)%, the differences were significantly (P < 0.01) compared with control [(2.0 +/- 1.3)% and (0.9 +/- 0.4)%]. Dihydroartemisinin inhibited the growth of pancreatic xenograft tumors in nude mice. The proliferation index and apoptosis index were (49.1 +/- 3.9)% and (50.2 +/- 4.4)% respectively in dihydroartemisinin 50 mg/kg treatment group, compared to those of (72.1 +/- 3.3)% and (9.4 +/- 2.9)% in control, the differences were significantly (P < 0.01). Western blot assay indicated that dihydroartemisinin up-regulates expression of proliferation-associated protein p21(WAF1) and down-regulates expression of PCNA, increases expression of apoptosis-associated protein Bax and decreases expression of Bcl-2 and activates caspase-9 in BxPC-3 cells.</p><p><b>CONCLUSIONS</b>Dihydroartemisinin exerts anti-tumor activity in pancreatic cancer both in vitro and in vivo by proliferation inhibition and apoptosis induction. Dihydroartemisinin can be used as a potential anti-tumor drug in pancreatic cancer.</p>

The effect of hyperbaric oxygen on acute pancreatitis through downregulating hypoxia-inducible factor / 中华外科杂志

<p><b>OBJECTIVE</b>To observe the therapeutic effect of hyperbaric oxygen (HBO) on acute pancreatitis (AP) by downregulating hypoxia-inducible factor (HIF).</p><p><b>METHODS</b>Forty Wistar rats were randomly divided into 4 groups (n = 10): sham group, AP group, normo-oxygen group (NP) and HBO group. At 4 hours after taurocholate-induced AP, the rats of NP group and HBO group were respectively treated with oxygen or HBO for 90 min. Several parameters were measured to evaluate oxygen stress after treatment including oxygen saturation (SaO2), partial pressure of oxygen (PO2), pH, and serum LDH. Pancreatic tissues were subjected to histopathological analysis, immunostained, and homogenized for Western blotted analysis of HIF-1alpha and VEGF, and measuring myeloperoxidase activity. The serum TNF-alpha and pancreatic histopathological scores were evaluated the severity of AP.</p><p><b>RESULTS</b>It was proved by immunohistochemisty that HIF in acinar cell and polymorphonuclear leukocytes (PMNs) was activated and transferred from cytoplasm into nucleus in AP group, NP group, and HBO group, following upregulation of VEGF. HBO therapy elevated blood SaO2 (99.6% +/- 0.7% vs. 87.7% +/- 1.8% or 91.2% +/- 2.5%, P < 0.05) and PaO2 [(369.1 +/- 67.6) mm Hg (1 mm Hg = 0.133 kPa) vs. (86.6 +/- 5.6) mm Hg or (99.9 +/- 4.0) mm Hg, P < 0.05]. HBO therapy attenuated the severity of AP through inhibiting AP-induced upregulation of HIF-1alpha and VEGF, as evidenced by reducing histopathological scores (12.40 +/- 1.21 vs. 16.45 +/- 1.10 or 16.38 +/- 1.10, P < 0.05), dry/wet weight ratio of pancreatic tissues, and myeloperoxidase activity.</p><p><b>CONCLUSIONS</b>HIF-1alpha plays a key role in the pathogenesis of AP. HBO therapy attenuates the severity of AP through downregulating the expression of HIF-1alpha.</p>

Interleukin-1 inhibits Sox9 and collagen type II expression via nuclear factor-kappaB in the cultured human intervertebral disc cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The most significant biological change in intervertebral disc degeneration is the decrease of chondrocyte specific gene and protein expression of Sox9 and collagen type II. Interleukin-1 (IL-1) is not expressed in the normal intervertebral disc tissue but increases in the degenerated intervertebral disc tissue. This suggests that IL-1 may play a role in regulation of the expression of Sox9 and collagen type II.</p><p><b>METHODS</b>Human intervertebral disc cells were isolated and cultured. Sox9 and collagen type II expression during treatment with IL-1, with or without the nuclear factor-kappaB (NF-kappaB) activity inhibitor curcumin, were detected by using reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, and the activity of the NF-kappaB signaling pathway was detected by the electrophoretic mobility shift assay (EMSA).</p><p><b>RESULTS</b>IL-1 lowered the mRNA level and protein expression of Sox9 and collagen type II in the cultured intervertebral disc cells in a dose dependent manner (P < 0.05), and this effect was attenuated by curcumin. Curcumin alone had no effect on Sox9 and collagen type II expression (P > 0.05). IL-1 at concentrations of 0.1 ng/ml, 1 ng/ml and 10 ng/ml could stimulate the activity of NF-kappaB in the intervertebral disc cells in a dose dependent manner (P < 0.05) that was inhibited by curcumin.</p><p><b>CONCLUSIONS</b>We demonstrated the previously unknown function of IL-1 in inhibiting Sox9 and collagen type II via NF-kappaB in the intervertebral disc cells. This inhibition can be attenuated by curcumin, which is an effective NF-kappaB activity inhibitor.</p>

The study on the morphology character of blood-spleen barrier / 中华外科杂志

<p><b>OBJECTIVE</b>To study the morphology and functional character of blood-spleen barrier (BSB) and establish the concept of BSB.</p><p><b>METHODS</b>Thirty healthy Wistar rats were studied. Ten rats were injected with 1.5 ml mixed fluid of India ink and physiological saline through the tail vein. Histological changes of the spleen in all animals were observed with light and electron microscopy, including HE, Foot, Masson staining and immunohistochemistry of CD68 and CD34.</p><p><b>RESULTS</b>Most of the carbon particles were within the splenic sinuses in marginal zone but not in the white pulp after 6 h. There was a characteristic distribution of the macrophagocytes, vessel endothelial cell, reticular tissue and collagen fiber in the BSB.</p><p><b>CONCLUSIONS</b>BSB, surrounding the white pulp, is composed of macrophagocytes, marginal-sinus-endothelial cells and their basement membrane, the reticular tissue (reticular cells and reticular fibers) and collagen fibers. The role of BSB is to keep the microenvironment of white pulp stable. It becomes mature while the formation of germinal center of the white pulp. The permeability of BSB changes during its development.</p>

Analysis of interleukin-1 receptor antagonist gene polymorphism in Chinese patients with Alzheimer's disease / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To identify an interaction between the interleukin-1 receptor antagonist gene polymorphism and risk of Alzheimer's disease.</p><p><b>METHODS</b>The study included 117 healthy controls, 85 patients with Alzheimer's disease in a Northeastern Chinese population of Han nationality. Genotypes were determined by a polymerase chain reaction amplification of the intron 2 fragment, harbouring a variable number of short tandem nucleotide sequences. Amplification products were separated on a 2% agarose gel.</p><p><b>RESULTS</b>The allele 2 frequency was 27% in healthy controls, and 21% in patients with Alzheimer's disease. Thus for allele 2 as well as for all other alleles, genotypes, or carriage rates, no significant differences compared with controls.</p><p><b>CONCLUSIONS</b>No association of interleukin-1 receptor antagonist gene polymorphism with Alzheimer's disease was identified in this population. It is also possible that the increased risk and disease modifying effects are caused by linkage disequilibrium with other genomic variants in other nearby genes.</p>