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Biomedical subjects

Yuman Fong

Publications and source records attributed to Yuman Fong.

At least 55 records · Page 3Linked to original sources
PubMed2005

Radiation therapy potentiates effective oncolytic viral therapy in the treatment of lung cancer.

BACKGROUND: Replication-competent oncolytic herpes simplex viruses with deletion of the gamma(1)34.5 gene preferentially replicate in and kill malignant cells. The gamma(1)34.5 gene codes for ICP 34.5, a protein that enhances viral replication, and is homologous to growth arrest and DNA damage protein 34 (GADD34), a radiation-inducible DNA repair gene. We hypothesized that radiation therapy may potentiate efficacy of oncolytic viral therapy by upregulating GADD34 and promoting viral replication. METHODS: The A549 and H1299 lung cancer cell lines were infected with NV1066, an oncolytic herpes simplex virus, at multiplicities of infection (number of viral particles per tumor cell) of 0.1 to 0.5 in vitro with radiation (2 to 10 Gy) or without radiation. Viral replication was determined by plaque assay, cell-to-cell spread was determined by flow cytometry, cell kill was determined by lactate dehydrogenase assay, and GADD34 induction was determined by real-time reverse transcription-polymerase chain reaction and Western blot method. Evidence of synergistic cytotoxicity dependence with GADD34 induction is further confirmed by small inhibitory RNA inhibition of GADD34 expression. RESULTS: Using both the isobologram method and combination index method of Chou and Talalay, significant synergism was demonstrated between radiation therapy and NV1066 both in vitro and in vivo. As a result of such synergism, a dose reduction for each agent (2- to 6,000-fold) can be accomplished for a wide range of therapeutic effect levels without sacrificing tumor cell kill. This effect is correlated with increased GADD34 expression and inhibited by transfection of small inhibitory RNA directed against GADD34. CONCLUSIONS: These data provide the cellular basis for the clinical investigation of combined use of radiation therapy with oncolytic herpes simplex virus therapy in the treatment of lung cancer to achieve synergistic efficacy while minimizing dosage and toxicity.

Animals↗
PubMed2005

Combination of mutated herpes simplex virus type 1 (G207 virus) with radiation for the treatment of squamous cell carcinoma of the head and neck.

G207 is an oncolytic herpes simplex virus (HSV) with deletions at both gamma134.5 loci and a LacZ gene insertion inactivating the HSV ribonucleotide reductase gene. Ionising radiation induces the growth arrest-inducible gene, GADD34, and ribonucleotide reductase. GADD34 is a protein that correlates with apoptosis following radiation and has homology with the G207 gamma134.5 gene. We hypothesised that the combination of radiotherapy with G207 may have a potentiating effect on viral replication and anti-tumour efficacy. The purpose of this study was therefore to evaluate the combination of G207 with radiation therapy to treat head and neck tumours. The cytotoxicity of G207 was tested in six head and neck squamous carcinoma cell lines, in the presence or absence of irradiation. For in vivo experiments, flank tumours in C3H/HeJ mice or in nude mice were treated with direct injections of G207, with or without radiation. All head and neck squamous cancer cell lines tested demonstrated significantly increased antitumour effects with the combination of G207 virus and radiation therapy compared with each individual modality (P<0.01). Furthermore, the combination treatment effect was better than the expected additive effect of the two therapies in combination. Even the radiation-resistant cell lines (SCC25, MSKQLL2, SCCVII) were susceptible. The combination of direct G207 injection with radiation therapy suppressed human and murine squamous cell carcinoma growth significantly (P<0.05 and P<0.001) compared with controls or single modality therapy. G207 enhanced the effectiveness of radiation therapy and low-dose radiation potentiated the effectiveness of G207 viral therapy in head and neck cancer. These findings suggest a potential clinical application for this combined therapy as treatment for radiation-resistant head and neck cancers.

Animals↗
PubMed2005

5-fluorouracil and gemcitabine potentiate the efficacy of oncolytic herpes viral gene therapy in the treatment of pancreatic cancer.

Oncolytic herpes viruses are attenuated, replication-competent viruses that selectively infect, replicate within, and lyse cancer cells and are highly efficacious in the treatment of a wide variety of experimental cancers. The current study seeks to define the pharmacologic interactions between chemotherapeutic drugs and the oncolytic herpes viral strain NV1066 in the treatment of pancreatic cancer cell lines. The human pancreatic cancer cell lines Hs 700T, PANC-1, and MIA PaCa-2 were treated in vitro with NV1066 at multiplicities of infection (MOI; ratio of the number of viral particles per tumor cell) ranging from 0.01 to 1.0 with or without 5-fluorouracil (5-FU) or gemcitabine. Synergistic efficacy was determined by the isobologram and combination-index methods of Chou and Talalay. Viral replication was measured using a standard plaque assay. Six days after combination therapy, 76% of Hs 700T cells were killed compared with 43% with NV1066 infection alone (MOI = 0.1) or 0% with 5-FU alone (2 micromol/L) (P < .01). Isobologram and combination-index analyses confirmed a strongly synergistic pharmacologic interaction between the agents at all viral and drug combinations tested (LD5 to LD95) in the three cell lines. Dose reductions up to 6- and 78-fold may be achieved with combination therapy for NV1066 and 5-FU, respectively, without compromising cell kill. 5-FU increased viral replication up to 19-fold compared with cells treated with virus alone. Similar results were observed by combining gemcitabine and NV1066. We have demonstrated that 5-FU and gemcitabine potentiate oncolytic herpes viral replication and cytotoxicity across a range of clinically achievable doses in the treatment of human pancreatic cancer cell lines. The potential clinical implications of this synergistic interaction include improvements in efficacy, treatment-associated toxicity, tolerability of therapeutic regimens, and quality of life. These data provide the cellular basis for the clinical investigation of combined oncolytic herpes virus therapy and chemotherapy in the treatment of pancreatic cancer.

Antineoplastic Agents↗
PubMed2005

Virally directed fluorescent imaging improves diagnostic sensitivity in the detection of minimal residual disease after potentially curative cytoreductive surgery.

Completeness of cytoreduction is an independent prognostic factor after cure-intended surgery for peritoneal carcinomatosis. NV1066, a genetically engineered herpes simplex virus carrying the transgene for green fluorescent protein, selectively infects cancer cells. We sought to determine the feasibility of virally directed fluorescent imaging in the intraoperative detection of minimal residual disease after cytoreductive surgery. NV1066 infected human gastric cancer cells, OCUM-2MD3, and mesothelioma JMN cells at all doses. The infected cells expressed green fluorescent protein and were killed. OCUM-2MD3, and mesothelioma JMN cells at all doses. Peritoneal carcinomatosis was established in mice by injection of OCUM cells into the peritoneal cavity. Forty-eight hours after intraperitoneal injection of NV1066, two experienced surgeons resected all visible disease and identified mice free of disease. Eight of 13 mice thought to be free of disease were found to have residual disease as identified by green fluorescence (mean number of observations: 5; range: 1-9). Residual disease was most frequently observed in the retroperitoneum, pelvis, peritoneal surface, and liver. Specificity of NV1066 infection to tumor nodules was confirmed by immunohistochemistry and by polymerase chain reaction for viral gene. Virally directed fluorescent imaging, a novel molecular imaging technology, can be used for real-time visualization of minimal residual disease after cytoreductive surgery and can improve the completeness of cure-intended resection.

Animals↗
PubMed2005

Predictors of intensive care unit admission and related outcome for patients after pancreaticoduodenectomy.

High-volume centers have low morbidity and mortality after pancreaticoduodenectomy (PD). Less is known about treatment pathways and their influence on intensive care unit (ICU) utilization. Patients who underwent PD at a tertiary cancer center during the five-year period between January 1998 and December 2003 were identified from a prospective database. Preoperative and intraoperative factors relating to ICU admission and outcome were analyzed. Five hundred ninety-one pancreaticoduodenectomies were performed during the study period. Of these, 536 patients had complete records for analysis. Of the 536 patients, 51 (10%) were admitted to the ICU after surgery. Admission to the ICU was associated with decreased overall survival (P < .0001). Of the preoperative predictors of ICU admission, serum creatinine, albumin, and increased body mass index (BMI) were associated with ICU admission (P = .02, .05, and .002, respectively). Age, blood glucose, diagnosis of diabetes mellitus, and chronic obstructive pulmonary disease were not predictive of ICU admission on univariate analysis. Of the intraoperative factors, longer operative time and estimated blood loss (EBL) correlated with ICU admission (P = .003 and .0001, respectively). On multivariate analysis, only preoperative BMI and intraoperative EBL were independent predictors of ICU admission (P = .03 and .003, respectively). Patients with a preoperative BMI greater than 30 had a substantially higher risk of ICU admission (relative risk 2.4). The majority of patients who undergo PD do not require admission to the ICU. Factors most associated with ICU admission after PD are increased preoperative BMI and intraoperative blood loss.

Adult↗
PubMed2005

Caudate hepatectomy for cancer: a single institution experience with 150 patients.

BACKGROUND: Resection of the caudate lobe of the liver is technically demanding, with the disparate goals of preserving major vascular and biliary structures without compromising tumor clearance. Our objective was to assess our results with resection of the caudate lobe of the liver for malignant disease. STUDY DESIGN: From 1992 to 2004, we performed caudate resection for malignancy in 150 patients. Clinicopathologic correlates, surgical methods, patterns of recurrence, and survival were analyzed. RESULTS: Of the 150 patients identified, 21 (14%) underwent an isolated caudate lobe resection and 129 (86%) underwent caudate lobe resection as part of a more extensive hepatectomy. The most common indication was for metastatic colorectal cancer (48%), followed by cholangiocarcinoma (30%) and hepatocellular cancer (10%). Thirty patients required resection and reconstruction of the portal vein (n = 16), vena cava (n = 15), or both. Pathologic microscopic margins were positive in 30 patients (20%). At least one postoperative complication was reported in the majority of patients (55%), and nine patients (6%) died as a result of these complications. Postoperative mortality was significantly higher in patients who underwent a major vascular reconstruction (20% versus 2.5%, p < 0.002). Median survivals for patients with colorectal metastasis, cholangiocarcinoma, and hepatocellular carcinoma were 37, 28, and 32 months, respectively. CONCLUSIONS: Performing caudate hepatectomy with negative microscopic margins remains a technical challenge because of the proximity of major biliary and vascular structures. Although caudate resection of the liver can be performed safely, concomitant major vascular reconstruction substantially increases the mortality of the procedure.

Adolescent↗
PubMed2005

Technical complications and durability of hepatic artery infusion pumps for unresectable colorectal liver metastases: an institutional experience of 544 consecutive cases.

BACKGROUND: Hepatic arterial infusion pump chemotherapy is an important component in the treatment of patients with hepatic metastases. Successful use of a hepatic arterial infusion pump requires a low technical complication rate. We evaluated the complications and longterm durability of these devices at our institution. STUDY DESIGN: Between April 1986 and March 2001, 544 patients underwent hepatic arterial infusion pump placement for treatment of unresectable colorectal liver metastases. Patient- and pump-related data were collected by chart review. Pump-related complications, duration of pump function, and overall patient survival were recorded. RESULTS: Median patient survival was 24 months after pump placement. The incidences of pump failure were 9% at 1 year and 16% at 2 years. Pump complications occurred in 120 (22%) of the patients. Complications that occurred early after operation (< 30 days) were more likely to be salvaged than those occurring late (70% versus 30%, p < 0.001). Increased pump complication rates occurred in the setting of variant arterial anatomy (28% versus 19%, p = 0.02), when the catheter was inserted into a vessel other than the gastroduodenal artery (42% versus 21%, p = 0.004), if the pump was placed during the first half of the study period (1986 to 1993, 25% versus 1994 to 2001, 18%; p = 0.05), and if the surgeon had performed fewer than 25 earlier procedures (< 25, 31% versus > or = 25, 19%; p < 0.002). CONCLUSIONS: In this large single institution experience, pump-related complications were low, the majority of early pump complications were salvaged, and pump complication rates improved as institutional experience accumulated. Longterm durability of pump function was excellent.

Catheterization↗
PubMed2005

Herpes simplex virus based gene therapy enhances the efficacy of mitomycin C for the treatment of human bladder transitional cell carcinoma.

PURPOSE: Oncolytic replication competent herpes simplex virus type-1 (HSV) mutants have the ability to replicate in and kill malignant cells. We have previously reported the ability of replication competent HSV to control bladder cancer growth in an orthotopic murine model. We hypothesized that the combination of a chemotherapeutic agent used for intravesical treatment, namely mitomycin C (MMC) (Bristol-Myers Squibb Oncology, Princeton, New Jersey), and oncolytic HSV would exert a synergistic effect for the treatment of human transitional cell carcinoma. MATERIALS AND METHODS: We used mutant HSV NV1066 (Medigene, San Diego, California), which is deleted for viral genes ICP0 and ICP4, and selectively infects cancer cells, to treat the transitional cell carcinoma lines KU19-19 and SKUB. Cell survival was determined by lactate dehydrogenase assay for each agent as well as for drug-viral combinations from days 1 to 5. The isobologram method and the combination index method of Chou-Talalay were used to assess the synergistic effect. RESULTS: NV1066 enhanced MMC mediated cytotoxicity at all combinations tested for KU19-19 and SKUB. The combination of the 2 agents demonstrated a synergistic effect and allowed dose reduction by 12 and 10.4 times (NV1066), and by 3 and 156 times (MMC) for the treatment of KU19-19 and SKUB, respectively, while achieving an estimated 90% cell kill. CONCLUSIONS: These data provide the cellular basis for the clinical investigation of combined MMC and oncolytic HSV therapy for the treatment of bladder cancer.

Antibiotics, Antineoplastic↗
PubMed2005

Comparison of survival rates after bland arterial embolization and ablation versus surgical resection for treating solitary hepatocellular carcinoma up to 7 cm.

PURPOSE: The vast majority of hepatocellular carcinomas (HCC) occur in patients with underlying liver dysfunction, making surgical resection available to only a subset of patients with adequate hepatic reserve. This study analyzes the authors' results with bland arterial embolization combined with radiofrequency ablation (RFA) or percutaneous ethanol injection (PEIT) compared with surgical resection for the treatment of solitary HCC up to 7 cm in size. MATERIALS AND METHODS: A retrospective review of all patients undergoing either surgical resection or bland embolization combined with local ablation for solitary HCC between January 1996 and August 2002 was performed. Progression-free survival rate and overall survival rate were calculated by the Kaplan-Meier method. RESULTS: There were 40 patients who underwent surgical resection and 33 patients who underwent embolization and ablation. Age, gender, and size of the treated lesion were not significantly different between the groups. The embolization/ablation group had more patients classified as Okuda stage II (P<.001). The surgical group had a longer median recurrence-free survival rate (53.1 vs 25.1 months). With a median follow-up of 23 months, the 1-, 3- and 5-year actuarial overall survival rates were 97%, 77%, and 56% for the embolization/ablation group and 81%, 70%, and 58% for the surgical group, respectively. There was no statistical difference in overall survival rates (P=.20). CONCLUSIONS: Bland arterial embolization in combination with ablation is effective in treating solitary HCC lesions up to 7 cm and achieves similar overall survival rates to surgical resection in selected patients.

Administration, Topical↗
PubMed2005

Partial hepatectomy for metastases from noncolorectal, nonneuroendocrine carcinoma.

OBJECTIVE: To define perioperative and long-term outcome and prognostic factors in patients undergoing hepatectomy for liver metastases arising from noncolorectal and nonneuroendocrine (NCNN) carcinoma. SUMMARY BACKGROUND DATA: Hepatic resection is a well-established therapy for patients with liver metastases from colorectal or neuroendocrine carcinoma. However, for patients with liver metastases from other carcinomas, the value of resection is incompletely defined and still debated. METHODS: Between April 1981 and April 2002, 141 patients underwent hepatic resection for liver metastases from NCNN carcinoma. Patient demographics, tumor characteristics, treatment, and postoperative outcome were analyzed. RESULTS: Thirty-day postoperative mortality was 0% and 46 of 141 (33%) patients developed postoperative complications. The median follow up was 26 months (interquartile range [IQR]) 10-49 months); the median follow up for survivors was 35 months (IQR 11-68 months). There have been 24 actual 5-year survivors so far. The actuarial 3-year relapse-free survival rate was 30% (95% confidence interval [CI], 21-39%) with a median of 17 months. The actuarial 3-year cancer-specific survival rate was 57% (95% CI, 48-67%) with a median of 42 months. Primary tumor type and length of disease-free interval from the primary tumor were significant independent prognostic factors for relapse-free and cancer-specific survival. Margin status was significant for cancer-specific survival and showed a strong trend for relapse-free survival. CONCLUSIONS: Hepatic resection for metastases from NCNN carcinoma is safe and can offer long-term survival in selected patients. Hepatic resection should be considered if all gross disease can be removed, especially in patients with metastases from reproductive tract tumors or a disease-free interval greater than 2 years.

Adrenal Cortex Neoplasms↗
PubMed2005

Papillary phenotype confers improved survival after resection of hilar cholangiocarcinoma.

OBJECTIVE: The current study compares outcome after resection of papillary hilar cholangiocarcinoma to that of the more common nodular-sclerosing subtype. METHODS: Clinical, radiologic, histopathologic, and survival data on all patients with hilar cholangiocarcinoma were analyzed. Resected tumors were reexamined and classified as nodular-sclerosing (no component of papillary carcinoma) or papillary (any component of papillary carcinoma); for papillary tumors, the proportion of invasive carcinoma present was determined. Differences in the clinical behavior and histopathologic features of nodular-sclerosing and papillary tumors were assessed. RESULTS: From January 1991 to November 2003, 279 patients were evaluated, 154 men (55.2%) and 125 women (44.8%), with a mean age of 65.4 +/- 0.7 years (median = 68, range 23-87 years). Of the 215 patients explored, 106 (49.5%) underwent a complete gross resection. An en bloc partial hepatectomy (n = 87) and an R0 resection (n = 82) were independent predictors of favorable outcome. Operative mortality was 7.5% but was 2.8% over the last 4 years of the study, and there were no operative deaths in the last 33 consecutive resections. Twenty-five resected tumors (23.6%) contained a papillary component: 12 were minimally or noninvasive (<10% invasive cancer) and 13 had an invasive component ranging from 10% to 95% (> or =10%). Patients with papillary and nodular-sclerosing tumors had similar demographics, operative procedures, and proportion of R0 resections. By contrast, papillary tumors were significantly larger, more often well-differentiated, and earlier stage. Disease-specific survival after resection of papillary tumors (55.7 months) was greater than after resection of nodular-sclerosing lesions (33.5 months, P = 0.013). The papillary phenotype was an independent predictor of survival, although the benefit was more pronounced for less invasive tumors. CONCLUSIONS: The presence of a component of papillary carcinoma is more common than previous reports have suggested and is an important determinant of survival after resection of hilar cholangiocarcinoma.

Adenocarcinoma, Papillary↗
PubMed2005

Long-term survival is superior after resection for cancer in high-volume centers.

BACKGROUND: A number of studies have demonstrated that surgical resection at high-volume centers is associated with improved short-term perioperative outcome. Whether long-term results after resection of visceral malignancies are superior at high-volume centers is largely unknown. METHODS: All patients who were subjected to pancreatectomy or hepatectomy for cancer in the years 1995 and 1996 were identified in the National Medicare database. Data extracted and examined include demographics, comorbidities, and long-term survival. All survival was confirmed through 2001, providing actual 5-year survival. Long-term survival was examined as related to hospital volume. RESULTS: In the study period, there were 2592 pancreatectomies and 3734 hepatectomies performed at 1101 and 1284 institutions, respectively. High-volume center was defined as >25 cases/y. By this definition, there were 10 high-volume centers for pancreatectomy and 12 centers for hepatectomy performing 11% (n = 291) of the pancreatectomies and 12% (n = 474) of the hepatectomies in this study period. Comparison by log-rank demonstrated superior survival for patients resected at high-volume centers (pancreatectomy: P = 0.001; hepatectomy: P = 0.02). This was confirmed by multivariate analysis. All analyses included an adjustment for within-center correlation. CONCLUSION: Superior long-term survival is associated with complex visceral resections for cancer at high-volume centers.

Aged↗
PubMed2005

Safety and efficacy of preoperative portal vein embolization with polyvinyl alcohol in 58 patients with liver metastases.

OBJECTIVE: The objective of our study was to evaluate the safety and efficacy of transhepatic lobar portal vein embolization (PVE) using polyvinyl alcohol (PVA) particles to induce contralateral lobar hypertrophy in patients with liver-only metastases and normal underlying liver function. MATERIALS AND METHODS: Fifty-eight consecutive patients with small predicted future liver remnants (FLRs) underwent PVE with PVA particles to induce hypertrophy of the contralateral hemi-liver before surgical resection of liver metastases. Total liver, right hemi-liver, and left hemi-liver volumes were calculated before and after embolization using a 3D workstation. RESULTS: Eight patients underwent left PVE; 47, right PVE; and three, right and segment IV PVE. There were no major complications of the procedure. The mean increases in the ratio of the FLR to the total estimated liver volume after right, right and segment IV, and left PVE were 9%, 10%, and 3%, respectively; the corresponding mean hypertrophy ratios were 24.3%, 31.9%, and 1.5%, respectively. CONCLUSION: Right PVE using PVA particles alone as the embolic agent is safe and effective in achieving left hemi-liver hypertrophy. In contrast, left PVE did not induce significant right hemi-liver hypertrophy in this patient population.

Adult↗
PubMed2004

Treatment of aggressive thyroid cancer with an oncolytic herpes virus.

Although many thyroid cancers carry a favorable prognosis, there is a subgroup of patients with more aggressive histologies. Current therapies offer no significant survival benefit to patients with anaplastic thyroid carcinomas, which are considered fatal. Oncolytic herpes simplex viruses (HSVs) have potent antitumor effects against a variety of human malignancies. We assessed the activity of a replication-competent, attenuated, oncolytic HSV (NV1023) against 7 different thyroid cancers, including one papillary (NPA-187), one follicular (WRO82-1), one medullary (DRO81-1) and 4 anaplastic (DRO90-1, ARO, KAT-4C and KAT-18) cell lines. Only the follicular WRO82-1 line was resistant to NV1023 infection and cell lysis at a concentration of 5 viral pfu per cell (MOI 5). All other cell lines at MOI 5 demonstrated >95% infection in vitro at day 2 by X-gal staining and >88% cell death at day 4 by cytotoxicity assays. Even at MOI 0.1, 4 of these lines displayed complete cell death by day 7. Viral proliferation assays revealed that all of the nonfollicular cell lines supported logarithmic viral replication. Flank tumors of NPA-187, DRO81-1, DRO90-1 and ARO in athymic nude mice were treated with NV1023 (2 x 10(7) pfu). All NPA-187 tumors completely regressed following a single dose. DRO81-1 tumors demonstrated partial response with a single dose and significant improvement with 3 serial doses. ARO and DRO90-1 tumors showed a significant response following either single injection (54 +/- 22 and 292 +/- 138 mm3, respectively) or 3 serial injections (33 +/- 14 and 241 +/- 68 mm3, respectively) compared to saline injections (472 +/- 193 and 1,257 +/- 204 mm3, respectively) at day 20. These data suggest that herpes oncolytic therapy may be effective for the treatment of aggressive thyroid carcinomas and merits further investigation.

Adenocarcinoma, Follicular↗
PubMed2004

Extent of hepatic resection does not correlate with toxicity following adjuvant chemotherapy.

BACKGROUND: In patients with liver metastases from colorectal cancer, survival can be increased by hepatic resection. Treatment with hepatic arterial infusion (HAI) and systemic chemotherapy following resection may further increase survival and decrease recurrence, but may also result in hepatic and systemic toxicity. This article will address the question of whether large hepatic resections resulting in a greater loss of healthy liver predisposes patients to developing toxicity from the subsequent chemotherapeutic regimens. DESIGN: Retrospective analysis of 88 patients who underwent liver resection of colorectal metastases followed by adjuvant HAI and systemic chemotherapy and whose computerized tomography (CT) scans were done at Memorial Sloan-Kettering Cancer Center (MSKCC). Liver volumes were calculated from CT scans and used to determine the percentage change in healthy liver volume between the pre- and post-operative CT scans. Hepatic and systemic toxicities were defined according to the Common Toxicity Criteria of the National Cancer Institute. RESULTS: Patients experienced a mean percentage decrease in healthy liver tissue of 17% (range: 57% decrease to 32% increase) at an estimated 1 month after resection and at the initiation of chemotherapy. In a logistic regression model using percentage change in the healthy liver volume as a continuous variable, no significant association was revealed between percentage of healthy liver resected and diarrhea (P = 0.47), leukopenia (P = 0.37), neutropenia (P = 0.31), high bilirubin (P = 0.27), or alkaline phosphatase (P = 0.79). CONCLUSIONS: A greater loss of healthy liver following resection of hepatic metastases from colorectal cancer does not seem to predispose to the development of toxicity from adjuvant HAI and systemic chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Angiogenesis inhibition by an oncolytic herpes virus expressing interleukin 12.

PURPOSE: Oncolytic herpes simplex viruses (HSVs) may have significant antitumor effects resulting from the direct lysis of cancer cells. HSVs may also be used to express inserted transgenes to exploit additional therapeutic strategies. The ability of an interleukin (IL)-12-expressing HSV to treat squamous cell carcinoma (SCC) by inhibition of tumor angiogenesis is investigated in this study. EXPERIMENTAL DESIGN: A replication-competent, attenuated, oncolytic HSV carrying the murine IL-12 gene (NV1042), its non-cytokine-carrying analog (NV1023), or saline was used to treat established murine SCC flank tumors by intratumoral injection. The expression of secondary antiangiogenic mediators was measured. Angiogenesis inhibition was assessed by in vivo Matrigel plug assays, flank tumor subdermal vascularity, and in vitro endothelial cell tubule formation assay. RESULTS: Intratumoral injections of NV1042 (2 x 10(7) plaque-forming units) into murine SCC VII flank tumors resulted in smaller tumor volumes as compared with NV1023 or saline. IL-12 and IFN-gamma expression in tumors was 440 and 2.2 pg/mg, respectively, at 24 h after NV1042 injection, but both IL-12 and IFN-gamma were undetectable (<0.2 pg/mg) after NV1023 or saline injections. Expression of two antiangiogenesis mediators, monokine induced by IFN-gamma and IFN-inducible protein 10, was elevated after NV1042 treatment. Matrigel plug assays of NV1042-transfected SCC VII tumor cells demonstrated significantly decreased hemoglobin content and microvessel density as compared with NV1023 and PBS. Excised murine flank tumors treated with NV1042 had decreased subdermal vascularity as compared with NV1023 and PBS. Both splenocytes and IL-12 expression by NV1042 were required for in vitro inhibition of endothelial tubule formation. CONCLUSIONS: IL-12 expression by an oncolytic herpes virus enhances therapy of SCC through antiangiogenic mechanisms. Strategies combining HSV oncolysis with angiogenesis inhibition merit further investigation for potential clinical application.

Animals↗
PubMed2004

Infection with oncolytic herpes simplex virus-1 induces apoptosis in neighboring human cancer cells: a potential target to increase anticancer activity.

PURPOSE: The antitumor efficacy of a herpes simplex virus (HSV)-1 oncolytic virus depends on the cytotoxic effect of the virus, but also on viral replication and spread within the tumor. Apoptosis is considered a defense mechanism of infected cells that minimizes the spread of viral progeny by limiting cellular production of virus. We sought to determine whether oncolytic HSV-1 infection induces apoptosis in neighboring, uninfected cells and whether manipulation of apoptosis can increase viral replication and cytotoxicity. EXPERIMENTAL DESIGN: NV1066 is an oncolytic HSV-1 mutant that contains the marker gene for enhanced green fluorescent protein. OCUM human gastric cancer cells were infected with NV1066 in vitro and inspected for apoptosis by Hoechst and terminal deoxynucleotidyltransferase-mediated nick end labeling staining and for infection by expression of green fluorescence. RESULTS: A significant increase in apoptosis was seen in cells infected by NV1066. More interestingly, a significant percentage (10%) of uninfected cells also proceeded to apoptosis. After NV1066 infection, cells were also treated with N-acetylcysteine (NAC), an inhibitor of apoptosis. By day 4 after infection, 2.7x more NV1066 was produced in cells exposed to NAC than in those not exposed to NV1066 (P = 0.04). NAC also increased tumor kill when administered with virus. CONCLUSIONS: These data suggest that NV1066 induces apoptosis in uninfected cocultured cells, potentially hindering propagation of viral progeny and concomitant tumor kill. Inhibition of apoptosis may improve the efficacy of oncolytic HSV-1 therapy.

Acetylcysteine↗