Construction and identification of a multiple myeloma-specific APE1 siRNA expression vector / 中华血液学杂志

<p><b>OBJECTIVE</b>To construct a multiple myeloma (MM)-specific APE1siRNA expression vector, and detect the specific knock-down effect of the siRNA on expression of APE1 protein.</p><p><b>METHODS</b>APE1siRNA cDNA sequence was designed, synthesized and inserted into pSilencer 2.0-U6 linear expression vector. pSilencer APE1siRNA was digested by enzyme EcoRI and BamHI, then linear vector and IgP fragments were conjugated by T4 DNA ligase. pSilencer IgP-APE1siRNA and pSilencer IE-IgP-APE1siRNA were digested by enzyme EcoRI or XhoI. Linear vector and IE or Kappa fragments were conjugated by T4 DNA ligase. Then a MM specific pSilencer K-IE-IgP-APE1siRNA was cloned. The recombinant products were identified by DNA sequencing and enzyme digestions at each step. pSilencer K-IE-IgP-APE1siRNA plasmid was transfected to KM3, HOS, MDA-231 cells by liposome. APE1 gene silence induced by RNAi was analysed by Western blot.</p><p><b>RESULTS</b>APE1 protein in KM3 cells could be knocked down effectively and specifically by pSilencer K-IE-IgP-APE1siRNA vector. After 2 days, the level of APE1 protein in KM3 cells transfected with siRNA was 0.118 +/- 0.047, while that transfected with plasmid only was 0.988 +/- 0.029. The efficiency of gene silence was 90%.</p><p><b>CONCLUSION</b>A MM specific APE1siRNA expression vector was successfully constructed.</p>

Characteristic and clinicopathologic significance of lymphangiogenesis in colorectal cancer / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the distribution patterns and proliferative activity of lymphatic vessels in colorectal carcinomas (CRC) and their relationship with tumor metastasis and disease prognosis.</p><p><b>METHODS</b>The microlymphatic density (MLD) and microvascular density in tumoral and non-tumoral areas of 96 cases of CRC were evaluated by immunohistochemistry, using monoclonal antibodies for podoplanin and CD34 respectively. The Ki-67 expression of the lymphatic and blood vessels was detected by double-labeling immunohistochemistry. The relationship between MLD and clinicopathologic features and prognosis was analyzed.</p><p><b>RESULTS</b>The lymph vessels at central and superficia1 portions of CRC often had a reticular architecture with numerous tiny and ill-defined lumina, while those at the tumor borders had large and open lumina. The MLD at tumor borders (51.2 +/- 25.5) was significantly higher than that in normal colorectal mucosa (29.4 +/- 9.0) and other portions of CRC (P < 0.01). The Ki-67 labeling index of the lymphatic lining cells at tumor borders (0.23 +/- 0.17) was significantly higher than that in other portions of CRC (P < 0.05). The MLD significantly correlated with lymphatic involvement by tumor cells, regional lymph node metastasis and distant metastasis (P < 0.01). The 5-year survival rate was also significantly lower in patients with high MLD (P < 0.05).</p><p><b>CONCLUSIONS</b>Neolymphatic vessels are commonly seen in CRC, especially at tumor borders. High MLD at tumor borders is associated with metastasis. The detection of MLD at tumor borders may thus be useful in predicting lymph node metastasis and prognosis in patients with CPC.</p>

An experimental study on the role of PGE2 and cAMP on the postburn change of the granulopoiesis in bone marrow in burned mice with endotoxemia / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the role of PGE(2) and cAMP in the postburn change in granulopoiesis in bone marrow in burned mice with endotoxemia.</p><p><b>METHODS</b>One hundred and seventy eight mice were randomly divided into burn with LPS administration, simple burn, simple LPS administration and control (injection of normal saline) groups. The COX-2 expression and the contents of PGE(2) and cAMP in myeloid cells in injured mice in all groups were determined by RIA (radioimmuno-assay) within 1 postburn week and immunohistochemistry methods. At the same time the change in granulopoiesis was dynamically observed.</p><p><b>RESULTS</b>The granulopoiesis was enhanced slightly at the early stage of burn and with endotoxin challenge, followed by suppression. The COX-2 expression in myeloid cells the contents of PGE(2) on supernatant of marrow cells and intracellular cAMP in the myeloid cells was increased at 12 postburn hour (PBH) up to 5 postburn day (PBD). Furthermore, the change in the cAMP was evidently and positively correlated with that of PGE(2) (r = 0.978, P < 0.01), but was negatively correlated with that of CFU-GM (r = -0.971, P < 0.01)</p><p><b>CONCLUSION</b>PGE(2) might play pivotal roles in the postburn granulopoiesis suppression in bone marrow during endotoxemia. This effect might be accomplished by its ligating to its special receptor and to activate adenylate cyclase so as to increase the intracellular content of cAMP in bone marrows.</p>