Wenquan Wang

Phase Ib Trial of Mutant Herpes Simplex Virus G207 Inoculated Pre-and Post-tumor Resection for Recurrent GBM

We have previously demonstrated safety of G207, a doubly mutated (deletion of both gamma(1)34.5 loci, insertional inactivation of U(L)39) herpes simplex virus (HSV) for patients stereotactically inoculated in enhancing portions of recurrent malignant gliomas. We have now determined safety of two inoculations of G207, before and after tumor resection. Inclusion criteria were histologically proven recurrent malignant glioma, Karnofsky score >or=70, and ability to resect the tumor without ventricular system breach. Patients received two doses of G207 totaling 1.15 x 10(9) plaque-forming units with 13% of this total injected via a catheter placed stereotactically in the tumor. Two or five days later, tumor was resected en bloc with catheter in place. The balance of G207 dose was injected into brain surrounding the resection cavity. Six patients with recurrent glioblastoma multiforme were enrolled. Two days after the second G207 inoculation, one patient experienced transient fever, delirium, and hemiparesis, which entirely resolved on high-dose dexamethasone. No patient developed HSV encephalitis or required treatment with acyclovir. Radiographic and neuropathologic evidence suggestive of antitumor activity is reported. Evidence of viral replication was demonstrated. G207 appears safe for multiple dose delivery, including direct inoculation into the brain surrounding tumor resection cavity.

Placebo-Controlled, Double-Blind Trial of Intravenous Ribavirin for the Treatment of Hantavirus Cardiopulmonary Syndrome in North America

UNLABELLED BACKGROUND. Ribavirin is active in vitro against hantaviruses, but the findings of an open trial of the use of intravenous ribavirin for the treatment of hantavirus cardiopulmonary syndrome (HCPS) were inconclusive. METHODS Subjects with suspected HCPS in the prodrome or cardiopulmonary phase but without shock were eligible for randomization to receive either intravenous ribavirin (33 mg/kg [<or=2 g], followed by 16 mg/kg [<or=1 g] given every 6 h for 4 days and by 8 mg/kg [<or=.5 g] given every 8 h for 3 days) or placebo (administered for 7 days or until the initial Sin Nombre virus antibody test result was confirmed to be negative). The primary outcome was survival at day 28 of the study without the need for extracorporeal membrane oxygenation (ECMO). RESULTS Thirty-six subjects were enrolled in the trial from March 1996 through July 2001, at which point the study was terminated prematurely because of both the slow rate of accrual of subjects and the findings of a futility analysis. Of the 36 subjects enrolled, 23 (all of whom were enrolled during the cardiopulmonary stage of HCPS) had HCPS confirmed by serologic testing. The severity of illness at entry into the study was similar among the 10 subjects with HCPS who received ribavirin and the 13 subjects with HCPS who received placebo. The proportion of subjects who survived and who did not require ECMO was similar among ribavirin recipients and placebo recipients (70% vs. 62%, respectively); 2 ribavirin recipients and 2 placebo recipients died, including 3 of 7 subjects treated with ECMO. The frequency of adverse events, including anemia, was similar between treatment groups. CONCLUSIONS The rate of accrual of subjects in the present study was inadequate to clearly assess the safety or efficacy of ribavirin in the treatment of HCPS. However, ribavirin was well tolerated, and the lack of trends supporting the use of intravenous ribavirin suggests that it is probably ineffective in the treatment of HCPS in the cardiopulmonary stage.

Lyn kinase activity is the predominant cellular SRC kinase activity in glioblastoma tumor cells.

Cellular Src activity modulates cell migration, proliferation, and differentiation, and recent reports suggest that individual members of the Src family may play specific roles in these processes. As we have found that Lyn, but not Fyn, activity promotes migration of glioblastoma cells in response to the cooperative signal generated by platelet-derived growth factor receptor beta and integrin alpha(v)beta3, we compared the activity and expression of Lyn and Fyn in glioblastoma (grade IV) tumor biopsy samples with that in anaplastic astrocytoma (grade III) tumors, nonneoplastic brain, and normal autopsy brain samples. Lyn kinase activity was significantly elevated in glioblastoma tumor samples. Notably, the Lyn kinase activity accounted for >90% of pan-Src kinase activity in glioblastoma samples but only approximately 30% of pan-Src kinase activity in the other groups. The levels of phosphorylation of the autophosphorylation site were consistent with significantly higher Lyn activity in glioblastoma tumor tissue than nonneoplastic brain. Although the normalized levels of Lyn protein and the relative levels of Lyn message were significantly higher in glioblastoma samples than nonneoplastic brain, the normalized levels of Lyn protein did not correlate with Lyn activity in the glioblastoma samples. There was no significant difference in the normalized levels of c-Src and Fyn protein and message in the glioblastoma and nonneoplastic brain. Immunostaining revealed that Lyn is located primarily in the glioblastoma cells in the tumor biopsies. These data indicate that Lyn kinase activity is significantly elevated in glioblastoma tumors and suggest that it is the Lyn activity that promotes the malignant phenotype in these tumors.

ABT-510, a modified type 1 repeat peptide of thrombospondin, inhibits malignant glioma growth in vivo by inhibiting angiogenesis

Anti-angiogenic therapies would be particularly beneficial in the treatment of malignant gliomas. Peptides derived from the second type 1 repeat (TSR) of thrombospondin-1 (TSP-1) have been shown to inhibit angiogenesis in non-glioma tumor models and a modified TSR peptide, ABT-510, has now entered into Phase II clinical trials of its efficacy in non-glioma tumors. As microvascular endothelial cells (MvEC) exhibit heterogeneity, we evaluated the ability of the modified TSR peptide (NAcSarGlyValDalloIleThrNvaIleArgProNHE, ABT-510) to inhibit malignant glioma growth in vivo and to induce apoptosis of brain microvessel endothelial cells (MvEC) propagated in vitro. We found that daily administration of ABT-510 until euthanasia (days 7 to 19), completely inhibited the growth of human malignant astrocytoma tumors established in the brain of athymic nude mice. The microvessel density was significantly lower and the number of apoptotic MvEC was significantly higher (3-fold) in the tumors of the ABT-510-treated animals. Similar results were found using a model in which the established tumor is an intracerebral malignant glioma propagated in a syngeneic mouse model. ABT-510 treatment of primary human brain MvEC propagated as a monolayer resulted in induction of apoptosis in a dose- and time-dependent manner through a caspase-8-dependent mechanism. It also inhibited tubular morphogenesis of MvEC propagated in collagen gels in a dose- and caspase-8 dependent manner through a mechanism that requires the TSP-1 receptor (CD36) on the MvEC. These findings indicate that ABT-510 should be evaluated as a therapeutic option for patients with malignant glioma.

Combination Treatment with TRA-8 Anti–Death Receptor 5 Antibody and CPT-11 Induces Tumor Regression in an Orthotopic Model of Pancreatic Cancer

Purpose: Evaluate the response of human pancreatic cancer cell lines and orthotopic tumors to TRA-8, an agonistic antibody to death receptor 5, in combination with irinotecan (CPT-11). Experimental Design: MIA PaCa-2 and S2VP10 cells were treated with TRA-8 and/or CPT 11. Cell viability was determined by ATP assay. JC-1 mitochondrial depolarization and Annexin V assays confirmed cell death by apoptosis. Immunoblotting was used to evaluate protein changes. MIA PaCa-2 cells were injected into the pancreas of severe combined immunodeficient mice. Mice underwent abdominal ultrasound to quantitate tumor size before and after treatment with twice weekly injections of 200 μg TRA-8 and/or 25 mg/kg CPT-11 for one or two treatment cycles, each lasting 2 weeks. Results: MIA PaCa-2 cells were more sensitive to TRA-8 and showed additive cytotoxicity, whereas S2VP10 cells showed synergistic cytotoxicity when treated with TRA-8 and CPT-11. Cell death occurred via apoptosis with increased cleavage of caspase-3, caspase-8, and caspase-9 and proapoptotic proteins Bid and poly(ADP)ribose polymerase after combination treatment compared with either agent alone. XIAP and Bcl-XL inhibitors of apoptosis were down-regulated. After a single cycle of in vivo combination therapy, tumor sizes had diminished significantly (P < 0.001) at 8 days posttreatment compared with no treatment, CPT-11, and TRA-8; and there was a 50-day increase in survival with combination treatment over untreated controls (P = 0.0002), 30 days over TRA-8, and a 36-day increase over CPT-11 monotherapy (P = 0.0003). With two cycles of TRA-8/CPT-11 treatment, mean survival time increased significantly (P < 0.001) to 169 days versus untreated controls, TRA-8 or CPT-11 (76, 121, or 108 days, respectively). Conclusions: Combination TRA-8 and CPT-11 therapy produced enhanced cytotoxicity and survival in the MIA PaCa-2 orthotopic model of pancreatic cancer.

The Effect of Neoadjuvant Chemotherapy on Histologic Grade, Hormone Receptor Status, and Her2/neu Status in Breast Carcinoma

Abstract:  The use of neoadjuvant chemotherapy prior to surgical resection for breast cancer is no longer restricted to patients with locally advanced disease. As preoperative treatment becomes more common, the question arises whether or not such therapy changes important tumor characteristics. The objective of our study is to compare histological grade, hormone receptor status, and HER2/neu expression pre‐ and post‐therapy patients receiving preoperative neo‐adjuvant chemotherapy. Forty patients status post‐neoadjuvant treatment who had available archived pathologic material pre‐ and post‐therapy were identified. Glass slides were reviewed retrospectively, and tumor grade, hormone receptor status, and HER2/neu expression were compared between the pre‐ and post‐therapy specimens. No significant differences were noted between the pre‐ and post‐specimens for two of the three parameters comprising the modified Bloom–Richardson grade, including degree of tubule formation (p = 0.062) and nuclear pleomorphism (p = 0.086). For mitotic activity, a decrease in score was observed between pre‐ and post‐therapy specimens which was statistically significant (p = 0.021). However, there was no significant difference in the overall modified Bloom–Richardson grade (p = 0.118). Information was available regarding hormone receptor and HER2/neu status in 26 patients (65%). There was no significant difference between pre‐ and post‐treatment specimens for hormone receptor status. However, there were more patients with HER2/neu overexpression after receiving neoadjuvant therapy (p = 0.027). Neoadjuvant therapy resulted in a significant decrease in mitotic count and an increase in the proportion of patients with Her2/neu overexpression. No significant changes were noted for the degree of tubule formation, nuclear pleomorphism, overall Bloom–Richardson score, and hormone receptor status. However, small sample size may be a limitation of these results.

TRA-8 anti-DR5 monoclonal antibody and gemcitabine induce apoptosis and inhibit radiologically validated orthotopic pancreatic tumor growth

Purpose: To evaluate agonistic TRA-8 monoclonal antibody to human death receptor 5 (DR5) and gemcitabine in vitro and in an orthotopic pancreatic cancer model. Experimental Design: Pancreatic cancer cell lines were screened for DR5 expression, cytotoxicity, and apoptosis induced by TRA-8, gemcitabine, or gemcitabine and TRA-8. An orthotopic model of pancreatic cancer was established in severe combined immunodeficient mice. Mice were treated with TRA-8, gemcitabine, or a combination for one or two cycles of therapy. Tumor growth (ultrasound) and survival were analyzed. Results: All five pancreatic cancer cell lines showed DR5 protein expression and varying sensitivity to TRA-8–mediated cytotoxicity. MIA PaCa-2 cells were very sensitive to TRA-8, moderately resistant to gemcitabine, with additive cytotoxicity to the combination. S2-VP10 cells were resistant to TRA-8 and sensitive to gemcitabine with synergistic sensitivity to the combination. Combination treatment in vitro produced enhanced caspase-3 and caspase-8 activation. A single cycle of therapy produced comparable efficacy for single-agent TRA-8 and the combination of TRA-8 and gemcitabine, with significant reduction in tumor size and prolonged survival compared with gemcitabine alone or control animals. With two cycles of therapy, TRA-8 and combination therapy produced enhanced inhibition of tumor growth compared with single-agent gemcitabine or untreated animals. However, the combination regimen showed enhanced survival as compared with single-agent TRA-8. Conclusions: Pancreatic cancer cell lines express varying levels of DR5 and differ in their sensitivity to TRA-8 and gemcitabine-induced cytotoxicity. TRA-8 with two cycles of gemcitabine therapy produced the best overall survival. [Mol Cancer Ther 2007;6(12):3198–207]

The effect of obesity on survival in patients with ovarian cancer

OBJECTIVE Data has suggested obesity as an independent prognostic factor for lower survival in patients with epithelial ovarian cancer (EOC). We sought to determine if obesity portends a disadvantage to surgical outcomes at the time of initial surgery affecting survival. METHODS A retrospective chart review of patients diagnosed with EOC was performed. All patients underwent primary cytoreductive surgery followed by taxane/platinum-based chemotherapy. Patient demographics, surgicopathologic and survival data were evaluated. Patients were compared based on body mass index (BMI) (<30 vs. > or =30) and BMI strata (underweight, normal weight, overweight, obese and morbidly obese). Survival analyses were performed with the Kaplan Meier method and compared using the log rank test, chi(2) test, and Fischers exact test. RESULTS 304 patients were identified. 71 patients (23%) were obese (BMI>30). The groups were similar in regard to stage, grade, histology, and chemotherapy administered. In regard to surgical outcomes, no difference was seen in estimated blood loss (EBL), operating room (OR) time, or operative complications excluding wound complications. Optimal debulking rates were similar in obese and non-obese patients (52% vs. 51% respectively, p=0.88). There was no statistical difference in progression free survival (17 vs. 11 months) or overall survival (48 vs. 40 months) between the two groups or across BMI strata. CONCLUSION Although obesity has been reported as an independent prognostic factor for survival, this data demonstrates that survival rates are similar between obese and non-obese patients when optimal debulking statuses are the same. Therefore, maximal effort should be directed towards optimal debulking obese patients with EOC.

Vascular endothelial growth factor reduces tamoxifen efficacy and promotes metastatic colonization and desmoplasia in breast tumors.

Clinical studies have shown that decreased tamoxifen effectiveness correlates with elevated levels of vascular endothelial growth factor (VEGF)-A(165) in biopsy samples of breast cancers. To investigate the mechanisms underlying tamoxifen resistance and metastasis, we engineered the estrogen receptor (ER)-positive MCF-7 human breast cancer cell line to express VEGF to clinically relevant levels in a doxycycline-regulated manner. Induction of VEGF expression in orthotopically implanted xenografts that were initially tamoxifen responsive and noninvasive resulted in tamoxifen-resistant tumor growth and metastasis to the lungs. Lung metastases were also observed in a VEGF-dependent manner following tail vein injection of tumor cells. At both primary and metastatic sites, VEGF-overexpressing tumors exhibited extensive fibroblastic stromal content, a clinical feature called desmoplasia. VEGF-induced metastatic colonies were surrounded by densely packed stromal cells before detectable angiogenesis, suggesting that VEGF is involved in the initiation of desmoplasia. Because expression of VEGF receptors R1 and R2 was undetectable in these tumor cells, the observed VEGF effects on reduction of tamoxifen efficacy and metastatic colonization are most likely mediated by paracrine signaling that enhances tumor/stromal cell interactions and increases the level of desmoplasia. This study reveals new roles for VEGF in breast cancer progression and suggests that combination of antiestrogens and VEGF inhibitors may prolong tamoxifen sensitivity and prevent metastasis in patients with ER-positive tumors.

Treatment of Human Colon Cancer Xenografts with TRA-8 Anti-death Receptor 5 Antibody Alone or in Combination with CPT-11

Purpose: This study was designed to evaluate the in vitro cytotoxicity and in vivo efficacy of TRA-8, a mouse monoclonal antibody that binds to the DR5 death receptor for tumor necrosis factor–related apoptosis-inducing ligand (also called Apo2L), alone and in combination with CPT-11, against human colon cancer cells and xenografts. Experimental Design: DR5 expression was assessed on human colon cancer cell lines using flow cytometry, and cellular cytotoxicity after TRA-8 treatment, alone and in combination with SN-38, was determined by measuring cellular ATP levels. Tumor growth inhibition and regression rates of well-established subcutaneous COLO 205, SW948, HCT116, and HT-29 colon cancer xenografts in athymic nude mice treated with TRA-8 or CPT-11 alone and in combination were determined. 99mTc-TRA-8 was used to examine tumor localization of TRA-8 in animals bearing each of the four xenografts. In addition, whole-body biodistribution and imaging was carried out in COLO 205–bearing animals using in vivo single-photon emission computed tomography imaging and tissue counting. Results: DR5 expression was highest on HCT116, intermediate on SW948 and COLO 205 cells, and lowest on HT-29 cells. COLO 205 cells were the most sensitive to TRA-8–induced cytotoxicity in vitro, SW948 and HCT116 cell lines were moderately sensitive, and HT-29 cells were resistant. Combination treatment with TRA-8 and SN-38 produced additive to synergistic cytotoxicity against all cell lines compared with either single agent. The levels of apoptosis in all cell lines, including HT-29, were increased by combination treatment with SN-38. In vivo, combination therapy with TRA-8 and CPT-11 was superior to either single-agent regimen for three of the xenografts: COLO 205, SW948, and HCT116. COLO 205 tumors were most responsive to therapy with 73% complete regressions after combination therapy. HT-29 cells derived no antitumor efficacy from TRA-8 therapy. Tumor xenografts established from the four colon cancer cell lines had comparable specific localization of 99mTc-TRA-8. Conclusions:In vitro and in vivo effects of TRA-8 anti-DR5 monoclonal antibody on four different colon cancer cell lines and xenografts were quite variable. The HT-29 cell line had low surface DR5 expression and was resistant to TRA-8 both in vitro and in vivo. Three cell lines (COLO 205, SW948, and HCT116) exhibited moderate to high sensitivity to TRA-8–mediated cytotoxicity which was further enhanced by the addition of SN-38, the active metabolite of CPT-11. In vivo, the combination of TRA-8 and CPT-11 treatment produced the highest antitumor efficacy against xenografts established from the three TRA-8–sensitive tumor cell lines. All four colon cancer xenografts had comparable localization of 99mTc-TRA-8. These studies support the strategy of TRA-8/CPT-11 combined treatment in human colon cancer clinical trials.