The combination of an mTORc1/TORc2 inhibitor with lapatinib is synergistic in bladder cancer in vitro

ObjectiveTo examine the ability of dual mTORc1/c2 inhibitors in conjunction with lapatinib to function in a synergistic manner to inhibit cell proliferation and anchorage-independent growth in bladder cancer cell lines.Materials and methodsWe examined patient tumor samples for overexpression of pS6, p4EBP1, pAkt, and phosphorylated epidermal growth factor receptor (pEGFR) using a tissue microarray containing 84 cases. Three bladder cancer cell lines, T24, HT1376, and UM-UC-3, were analyzed for cell proliferation after treatment with mTORc1/c2 inhibitors OSI-027 or PP242. Western blots were used to verify that the drugs were inhibiting phosphorylation of target proteins within the mTOR pathway, and they were compared with rapamycin inhibition. We also analyzed cell proliferation and anchorage-independent growth after treatment with OSI-027 and lapatinib in combination. PARP cleavage and autophagic flux were measured by examining levels of LC3B and p62 by western blotting.ResultsTumor samples show increased expression of pEGFR (38% vs. 8%) and HER2 (38% vs. 4%) and decreased expression of pAkt S473 (7.5% vs. 29%) and pAkt T308 (50% vs. 84%) relative to normal tissue. Significant differences between normal and tumor samples for staining with pEGFR (P = 0.0188), HER 2 (P = 0.0017), pATK S473 (P = 0.0128), and pAkt T308 (P = 0.0015) is observed. Expression of proteins within the EGFR/HER2 pathway or within the mTOR pathway is correlated. No correlation was found between staining and tumor stage. OSI-027 and PP242 diminish cell proliferation in all 3 cell lines with IC₅₀ values ranging from 0.63 to 17.95 µM. Both drugs inhibit phosphorylation of both mTORc1 and mTORc2 pathway components. OSI-027 and lapatinib inhibit cell proliferation and anchorage-independent growth in a synergistic manner. One cell line exhibited apoptosis in response to combination drug treatment, whereas the other 2 cell lines have increased levels of autophagy indicative of resistance to apoptosis.ConclusionsThe combination of OSI-027 and lapatinib results in antitumor synergy and further exploration of this combination should be undertaken.     

METH1在酵母双杂交系统中的表达及对报告基因激活作用的检测

目的通过观察血管生成抑制因子METH1的cDNA片段在酵母双杂交中的表达及检测其对报告基因有无激活作用，为进一步明确METHI抑制增生性瘢痕的分子机制奠定基础。方法采用酵母双杂交Ga14系统3，经PCR扩增子METH1的cDNA片段，分别克隆入pUC19质粒，经测序正确后。再分别亚克隆入酵母双杂交诱饵载体pGBKT7中。将重组质粒导入酵母菌AH109，检测其表达产物在酵母细胞中对报告基因的激活作用。结果成功获得METH1的cDNA片段，该片段所表达的蛋白对酵母菌AH109无毒性，且对报告基因无激活作用。结论血管生成抑制因子METH1蛋白活性区在酵母双杂交系统中的表达产物。可作为诱饵蛋白进行相互作用蛋白的筛选研究。     

METH1在酵母双杂交系统中的表达及对报告基因激活作用的检测

目的通过观察血管生成抑制因子METH1的cDNA片段在酵母双杂交中的表达及检测其对报告基因有无激活作用,为进一步明确METH1抑制增生性瘢痕的分子机制奠定基础。方法采用酵母双杂交Gal4系统3,经PCR扩增子METH1的cDNA片段,分别克隆入pUC19质粒,经测序正确后,再分别亚克隆入酵母双杂交诱饵载体pGBKT7中。将重组质粒导入酵母菌AH109,检测其表达产物在酵母细胞中对报告基因的激活作用。结果成功获得METH1的cDNA片段,该片段所表达的蛋白对酵母菌AH109无毒性,且对报告基因无激活作用。结论血管生成抑制因子METH1蛋白活性区在酵母双杂交系统中的表达产物,可作为诱饵蛋白进行相互作用蛋白的筛选研究。     

Synaptic vesicle protein 2B is expressed in podocyte, and its expression is altered in proteinuric glomeruli

Synaptic vesicle protein 2B (SV2B) was identified by the subtraction hybridization technique as a molecule of which mRNA expression was decreased in puromycin aminonucleoside (PAN) nephropathy by glomerular cDNA subtraction assay. The expression of SV2B was detected in glomerular lysate with Western blot analysis. Dual-labeling immunofluorescence studies with glomerular cell markers demonstrated that SV2B is expressed in glomerular visceral epithelial cells (podocytes). The expression of SV2B is detected also in cultured podocyte and in human kidney section as podocytic pattern. The decrease of SV2B mRNA was already detected before the onset of proteinuria in PAN nephropathy. The mRNA expression of SV2B clearly is altered not only in PAN nephropathy but also in another proteinuric state that is caused by an antibody against nephrin, a functional molecule of the slit diaphragm. The decreased intensity in SV2B staining was already detected before the peak of proteinuria in both models with immunofluorescence study. A reduced amount of SV2B was detected in both models also with Western blot analysis. CD2AP, another functional molecule of the slit diaphragm, was observed in cytoplasm, including the processes area of the cultured podocyte, and when the podocyte was treated with small interfering RNA for SV2B, CD2AP staining at the process area was not detected. These results suggest that SV2B is a functional molecule of podocyte, and SV2B may play a role in the expression and proper localization of CD2AP.     

Pleiotrophin is an abundant protein in dissociative extracts of bovine fetal epiphyseal cartilage and nasal cartilage from newborns

An abundant protein that is identical to the growth-associated protein pleiotrophin (PTN) has been isolated from dissociative extracts of bovine nasal and fetal epiphyseal cartilage. The yield from these tissues was at least 15 μg/g wet weight of cartilage. PTN was absent or was present only in trace amounts in mature articular cartilage. An analysis of tryptic fragments of PTN, held together with disulfide bonds, did not indicate any set pattern of cystine cross-links, which suggests a propensity for rapid refolding of the protein. PTN could not be isolated from thin (10 μm) slices of nasal cartilage in physiological extraction buffers, which indicates that it was tightly associated with the cell surface, was tightly associated with nonextractable matrix, or was an intracellular protein. Its appearance in various extraction media parallels that of histone H2b, a nucleosomal protein; this suggests a possible intracellular location for the protein. Immunohistochemical analysis of its distribution in fetal epiphysis indicated that it is associated with chondrocytes.     

Complement activation during bypass in acquired C1 esterase inhibitor deficiency

Serial complement estimations during cardiopulmonary bypass are reported in a patient with acquired C1 esterase inhibitor deficiency. Although the extent of classic and alternative pathway activation appeared appropriate, exaggerated common pathway activation with massive increase in the C3d:C3 ratio occurred. A fatal hemostatic disorder, pulmonary edema, and circulatory collapse ensued despite prophylaxis and therapy.     

Cyclooxygenase-2 is highly expressed in carcinoma in situ and T1 transitional cell carcinoma of the bladder

PURPOSE: We describe cyclooxygenase-2 (COX-2) expression patterns in patients with carcinoma in situ and/or stage T1 transitional cell carcinoma. We determined whether expression is associated with clinical outcome in these patients. MATERIALS AND METHODS: Immunostaining for COX-2 was performed on paraffin embedded bladder biopsy specimens from 2 independent groups of patients without muscle invasive carcinoma, including 39 with carcinoma in situ and 34 with stage T1 tumors. Immunoreactivity was scored as the percent of carcinoma in situ cells with cytoplasmic staining for COX-2 in the carcinoma in situ group and as the percent of stage T1 cells expressing COX-2 in the stage T1 transitional cell carcinoma group. We evaluated other molecular alterations, including E-cadherin, p21 and p53, because evidence suggests a biological association of COX-2 with alterations in these molecular markers. RESULTS: In the carcinoma in situ group 5 patients (13%) had no immunoreactivity, while 2 (5%), 5 (13%) and 27 (69%) had 10%, 20% and 30% or greater carcinoma in situ cells positive for COX-2, respectively. In the transitional cell carcinoma group 1 (3%), 4 (12%) and 29 (85%) patients had 10%, 20% and 30% or greater positive cells, respectively. COX-2 expression was not associated with any clinical or pathological parameters, or with molecular markers regardless of the cutoff used. It was also not associated with clinical outcomes in the stage T1 transitional cell carcinoma group. In the carcinoma in situ group COX-2 expression was significantly associated with disease recurrence using cutoffs of 0% and greater than 10% positive cells, and with disease progression using a greater than 20% cutoff. However, it was not associated with bladder cancer related survival. CONCLUSIONS: COX-2 is expressed in a high percent of patients with carcinoma in situ and stage T1 transitional cell carcinoma, supporting the rationale for chemoprevention studies with selective COX-2. We could not substantiate a role for COX-2 immunohistochemistry for the staging and prognosis of carcinoma in situ and/or stage T1 transitional cell carcinoma.     

Protease inhibitor monotherapy is associated with a higher level of monocyte activation,bacterial translocation and inflammation

Introduction

Monotherapy with protease-inhibitors (MPI) may be an alternative to cART for HIV treatment. We assessed the impact of this strategy on immune activation, bacterial translocation and inflammation.

Methods

We performed a cross-sectional study comparing patients on successful MPI (n=40) with patients on cART (n=20). Activation, senescence, exhaustion and differentiation stage in CD4+ and CD8+ T lymphocyte subsets, markers of monocyte activation, microbial translocation, inflammation, coagulation and low-level viremia were assessed.

Results

CD4+ or CD8+ T lymphocyte subset parameters were not significantly different between both groups. Conversely, as compared with triple cART, MPI patients showed a higher proportion of activated monocytes (CD14+ CD16−CD163+ cells, p=0.031), soluble markers of monocyte activation (sCD14 p=0.004, sCD163 p=0.002), microbial translocation (lipopolysaccharide (LPS)-binding protein; LBP p=0.07), inflammation (IL-6 p=0.04) and low-level viremia (p=0.035). In a multivariate model, a higher level of CD14+ CD16−CD163+ cells and sCD14, and presence of very low-level viremia were independently associated with MPI. Monocyte activation was independently associated with markers of inflammation (IL-6, p=0.006), microbial translocation (LBP, p=0.01) and low-level viremia (p=0.01).

Conclusions

Patients on MPI showed a higher level of monocyte activation than patients on standard therapy. Microbial translocation and low-level viremia were associated with the high level of monocyte activation observed in patients on MPI. The long-term clinical consequences of these findings should be assessed.