Long non-coding RNA MEG3 inhibits the proliferation of cervical carcinoma cells through the induction of cell cycle arrest and apoptosis

Cervical cancer remains an important public health problem worldwide. New and effective therapeutic strategies targeting cervical cancer are urgently needed. Long non-coding RNAs (lncRNAs) are newly identified regulators in tumorigenesis and tumor progression. To investigate the role of lncRNA MEG3 in the development of cervical cancer, we examined MEG3 expression in 18 pairs of cervical cancer and matched adjacent non-neoplastic tissues. Real-time quantitative RT-PCR (qRT-PCR) results showed high expression levels of MEG3 in non-neoplastic tissues, but markedly lower levels in cancer tissues. We further investigated whether the restoration of MEG3 expression might affect the proliferation of cervical carcinoma cells. Ectopic expression of MEG3 inhibited the proliferation of human cervical carcinoma cells HeLa and C-33A in vitro. On the other hand, knockdown of MEG3 promoted the growth of well-differentiated cervical carcinoma HCC94 cells. Further investigation into the mechanisms responsible for the growth inhibitory effects revealed that overexpression of MEG3 resulted in the induction of G2/M cell cycle arrest and apoptosis. These results identified an important role of MEG3 in the molecular etiology of cervical cancer and implicated the potential application of MEG3 in cervical cancer therapy.

A steep radioiodine dose response scalable to humans in sodium-iodide symporter (NIS)-mediated radiovirotherapy for prostate cancer

The sodium iodide symporter (NIS) directs the uptake and concentration of iodide in thyroid cells. We have extended the use of NIS-mediated radioiodine therapy to prostate cancer. We have developed a prostate tumor specific conditionally replicating adenovirus (CRAd) that expresses hNIS (Ad5PB_RSV-NIS). For radiovirotherapy to be effective in humans, the radioiodine dose administered in the pre-clinical animal model should scale to the range of acceptable doses in humans. We performed ¹³¹I dose-response experiments aiming to determine the dose required in mice to achieve efficient radiovirotherapy. Efficacy was determined by measuring tumor growth and survival times. We observed that individual tumors display disparate growth rates which preclude averaging within a treatment modality indicating heterogeneity of growth rate. We further show that a statistic and stochastic approach must be used when comparing the effect of an anti-cancer therapy on a cohort of tumors. Radiovirotherapy improves therapeutic value over virotherapy alone by slowing the rate of tumor growth in a more substantial manner leading to an increase in survival time. We also show that the radioiodine doses needed to achieve this increase scaled well within the current doses used for treatment of thyroid cancer in humans.

The evaluation of flaxseed for hot flashes: Results of a randomized, controlled trial, NCCTG study N08C7

CRA9015

Background: Hot flashes are a common symptom during the menopause transition or following breast cancer treatment that can negatively impact the quality of life for many women. Preliminary data have suggested that flaxseed, a rich source of dietary lignans, may be a potentially effective treatment for hot flashes. Methods: A phase III randomized, placebo controlled trial was conducted to evaluate the efficacy of flaxseed in reducing hot flashes. Postmenopausal women were randomly assigned to a flaxseed bar (providing 410 mg of lignans) for 6 weeks vs a placebo bar. Participants completed daily prospective, self report hot flash diaries during the baseline week and then began eating one study bar per day for 6 weeks, while continuing to record their daily hot flashes. The intra-patient difference in hot flash activity between baseline and the last treatment week was the primary endpoint. Side effects of the bars were evaluated through self report and CTC assessment. Results: Between October and December 2009, 188 women were enrolled onto this trial. Mean hot flash scores were reduced by 4.9 units in the flaxseed group and 3.5 in the placebo group (p=0.29). In both groups, a little over a third of the women received a 50% reduction in their hot flash scores. Only one side effect was significantly different between groups, that being grade 1 pruritis, which was more common (7%) in the placebo group versus 1% in the flaxseed group. Both groups reported increased abdominal distension, flatulence, diarrhea and nausea. Adherence and ability to detect treatment assignment did not differ between groups. Conclusions: The results of this trial do not support the use of 410 mg of flaxseed lignans for the reduction of hot flashes. The gastrointestinal side effects seen in both groups were likely due to the fiber content in the flaxseed and placebo bars.

MC0553: A phase II safety and efficacy study with the VEGF receptor tyrosine kinase inhibitor pazopanib in patients with metastatic urothelial cancer

259

Background: Vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF) are produced by bladder cancer cell lines in vitro and expressed in human tumor tissues. Preclinical studies have also shown that bladder cancer cell lines express VEGF receptor 1 and 2 on their surface membrane. Pazopanib is a vascular endothelial receptor tyrosine kinase inhibitor with anti-angiogenesis and antitumor activity in several preclinical models. A two-stage phase II study was conducted to assess the activity and toxicity profile of pazopanib administered to patients with metastatic, urothelial carcinoma.

Methods: Patients with one prior systemic therapy for recurrent, metastatic urothelial carcinoma were eligible. Patients received pazopanib at a dose of 800 mg orally daily for 4 week cycle.

Results: Nineteen patients were enrolled. Median age was 66 years, with > 89% of patients presenting poorly differentiated bladder cancer. Adverse event data is available on 18 patients. No grade 4 or 5 events have been experienced. Nine patients have experienced 11 grade 3 adverse events of which 7 were deemed at least possibly related to treatment. Most common toxicities were anemia, thrombocytopenia, leucopenia and fatigue. For stage 1, none of the first 16 evaluable patients were deemed success (CR or PR) by the RECIST criteria during the first four 4-week cycles of treatment. Median progression- free survival was 1.9 months. This met the futility stopping rule of interim analysis, and therefore, the trial was recommended to be permanently closed. Correlative studies including measurement of VEGF levels in archived tissues and blood are pending.

Conclusions: Pazopanib did not show activity in urothelial carcinoma patients. The role of anti-VEGF therapies in urothelial carcinoma may need further evaluation in rational combination strategies.

[Table: see text]

Utilizing spiral computerized tomography during the removal of a fractured endodontic instrument lying beyond the apical foramen

AIM

To present a case that used spiral computerized tomography (CT) to locate and successfully remove a fractured endodontic instrument lying beyond the apical foramen using a surgical approach.

SUMMARY

The fracture of an endodontic instrument beyond the apical foramen is rare. In this case report, after an attempt to remove a fractured instrument failed, a multi-slice spiral computerized tomography (MSCT) was used for diagnosis and treatment planning. The fractured segment was precisely located and found in the soft tissue and successfully removed by surgery. For the successful removal of a fractured endodontic instrument beyond the apical foramen, the following are necessary: (i) knowledge of the cause of fracture and how to plan treatment; (ii) determining the precise location of the fractured segment using CT; and 3) skilful operation.

KEY LEARNING POINTS

•  Fractured endodontic instruments might lie within the soft tissue. •  Computerized tomography is an effective diagnostic aid for localizing the precise position of fractured instruments.

Lateral movement of soil fumigants 1,3-dichloropropene and chloropicrin from treated agricultural fields

The soil fumigants 1,3-dichloropropene (1,3-D) and chloropicrin (CP) are often used for controlling soil-borne plant pathogens and parasitic nematodes before reestablishing new vineyards and orchards. To evaluate crop safety and environmental risks with the replant fumigation, four field experiments were performed over 2 yr to examine 1,3-D and CP lateral movement away from the treated fields. Shank injection with or without a virtually impermeable film (V1F) was used in two vineyard fumigation experiments, and spot drip application without tarp cover was used in two orchard experiments. Results showed that 1,3-D and CP gases moved laterally to 6 m from the treated fields when the fumigants were applied by shank injection. The maximum 1,3-D or CP soil gas concentration at 6 m was approximately 10 ng cm(-3) when the fumigated plot was not cover with a tarp. With VIF, the measured maximum concentration increased to approximately 100 ng cm(-3). In the spot drip application, maximum 1,3-D and CP gas concentrations reached approximately 100 ng cm(-3) but at 1.5 m radial distance from the point of fumigant injection.

A probasin promoter, conditionally replicating adenovirus that expresses the sodium iodide symporter (NIS) for radiovirotherapy of prostate cancer

The sodium iodide symporter (NIS) directs the uptake and concentration of iodide in thyroid cells. We have extended the use of NIS-mediated radioiodine therapy to other types of cancer, we transferred and expressed the sodium-iodide symporter (NIS) gene into prostate, colon, and breast cancer cells using adenoviral vectors. To improve vector efficiency we have developed a conditionally replicating adenovirus (CRAd) in which the E1a gene is driven by the prostate specific promoter, Probasin and the cassette RSV promoter-human NIScDNA-bGH polyA replaces the E3 region (CRAd Ad5PB_RSV-NIS). In vitro infection of the prostate cancer cell line LnCaP resulted in virus replication, cytolysis, and release of infective viral particles. Conversely, the prostate cancer cell line PC-3 (androgen receptor negative) and the pancreatic cancer cell line Panc-1 were refractory to the viral cytopathic effect and did not support viral replication. Radioiodine uptake was readily measurable in LnCaP cells infected with Ad5PB_RSV-NIS 24 hours post-infection, confirming NIS expression. In vivo, LnCaP tumor xenografts in nude mice injected intratumorally with Ad5PB_RSV_NIS CRAd expressed NIS actively as evidenced by ⁹⁹Tc uptake and imaging. Administration of therapeutic ¹³¹I after virus injection significantly increased survival probability in mice carrying xenografted LnCaP tumors compared to virotherapy alone. The data indicate that Ad5PB_RSV_NIS replication is stringently restricted to androgen positive prostate cancer cells and results in effective NIS expression and uptake of radioiodine. This construct may allow multimodal therapy, combining cytolytic virotherapy with radioiodine treatment, to be developed as a novel treatment for prostate cancer.

Spot fumigation: fumigant gas dispersion and emission characteristics

Reducing emissions of volatile organic compounds (VOCs) from fumigant pesticides is mandatory in California, especially in "nonattainment areas" like the San Joaquin Valley that do not meet federal air quality standards. A two-year field study was conducted to examine the feasibility of site-specific fumigant application only at future tree sites with dramatically reduced amounts of fumigant chemicals on an orchard basis. Soil gas distribution and atmospheric emission of 1,3-dichloropropene and chloropicrin were measured after applying InLine using subsurface drip irrigation. It was predicted that except in the surface 20 cm of soil, satisfactory pest control could be achieved within a 15 cm radius from the injection point. Also, at radial distances of 15-51 cm from the point of fumigant injection, effective nematode control may be achieved. Cumulative atmospheric emission of the fumigants was estimated to be 18-23% of the applied active ingredients in plots that had been cover cropped with Sudan grass and 2-6% in plots that had remained bare for several months before treatment. Considering the significantly small amount of fumigant used on an orchard basis, the spot drip fumigation may achieve a 10-fold reduction in atmospheric VOCs load from fumigant pesticides.

Relationship of sensory symptoms and motor function in patients with chemotherapy-induced peripheral neuropathy (CIPN) utilizing the EORTC QLQ CIPN20: NCCTG study N06CA

9587

Background: CIPN is characterized by adjectives not covered directly by most common measures of pain and functional limitations. Possible descriptors include numbness, tingling and shooting/burning pain. A prospective neuropathy treatment trial provided data to explore the relationship between self-reported aspects of this symptom. Methods: Baseline EORTC QLQ CIPN20 data and NCI CTCAE V3.0 (CTC)neuropathy grade (I-IV) were provided for all patients on trial. Spearman correlation coefficients and Kappa's coefficients of agreement were calculated between individual items and subscales of the CIPN20 as well as the CTC neuropathy scale. Simple regression models were applied to examine the association between the sensory symptoms and motor function in the fingers/hands (F/H). 200 patients provided 80% power to detect a correlation coefficient of 0.20 with a 5% Type I error. Results: A majority of patients reported “quite a bit” to “very much” numbness (57%) or tingling (62%) in F/H compared to “a little” or “not at all” (numbness (43%), tingling (38%)) by the CIPN20. In contrast, only 13% of the participants had grade III/IV neuropathy determined by the CTC scale. Fewer patients reported the higher two levels of CIPN20-measured shooting/burning pain in F/H (20% “quite a bit” to “very much”). Numbness and tingling were highly correlated (kappa=0.56), while neither were in high agreement with shooting/burning pain (kappa= 0.05 (tingling) and 0.14 (numbness)). The CIPN20 sensory and motor subscales were significantly associated with each other (p<.0001) but were not or only weakly associated with the CTC. Specifically, tingling, numbness, and shooting/burning pain were not associated with the CTC (R=0.16, 0.18 and 0 .11, respectively). Using the CIPN20, all three sensations; numbness, tingling and shooting or burning pain were strongly associated with motor function. Conclusions: The most common moderate to severe CIPN symptoms were numbness and tingling with shooting/burning pain being less common. Shooting/ burning pain appears to be a separate symptom experience from numbness and tingling. The CTC neuropathy grading scale appears to be less sensitive than the CIPN20 in picking up sensory symptoms.

No significant financial relationships to disclose.

Phase I/II trial of CCI 779 and bevacizumab in advanced renal cell carcinoma (RCC): Safety and activity in RTKI refractory RCC patients

5039

Background: Combined mTOR and VEGF blockade is a potentially promising and rational strategy for the treatment of advanced RCC. We previously reported the phase I safety and efficacy results of CCI 779 (C) +bevacizumab (B) n RTKI naïve stage IV RCC patients (pts) (J Clin Oncol. 2007;25[18S Suppl]:5034). We now report the interim results of the phase 2 study of C+B in RTKI refractory RCC patients. Methods: Design: Open label, phase I/II study of C+B in advanced RCC pts. Patients with measurable stage IV RCC with a component of clear/conventional cell type, performance status 0–2 and good organ function were eligible. Up to two prior treatment regimens were allowed (at least one prior RTKI). Phase II dose was C = 25 mg IV weekly and B = 10 mg/kg every 2 weeks repeated in 4 week cycles. The primary objective of the phase II portion was to assess the proportion of patients who were progression-free 6 months after study entry. Secondary objectives were assessment of response rates and toxicity. Accrual goal = 40 pts. Results: Thirty-five pts have been enrolled into the phase 2 portion to date with 4 pts ineligible. Twenty-five pts are evaluable for response assessment and 29 pts are evaluable for toxicity. Baseline characteristics (N: 35): M/F: 28/7; Number of met. sites: 1/2/3+: 15/9/11; prior nephrectomy: 31; Number of prior therapies: 1 = 29; 2 = 2. Most common (>5%) Gr 3–4 AEs (N = 29) included fatigue (6), hypercholesterolemia (2), hypertriglyceridemia (2), anorexia (2), rash (2), and anemia (2). Responses were: PR/SD/PD = 4 (16%)/18 (72%)/3 (12%). Median number of cycles administered was 4. Six month progression free rates will mature by may 2009. Conclusions: C+B combination at the recommended phase 2 doses is feasible and well tolerated. Clinical benefit rates (PR/SD) in RTKI refractory RCC patients (88%) are encouraging. Data on 6 month progression-free rates are expected to mature in 4/09. Updated data on safety, response rates, and 6-month progression free rates will be presented on all evaluable patients. Correlative studies on available plasma, serum and tumor samples for angiogenic and molecular biomarkers are underway. Supported by N01-CM62205, R21 CA 119545–02, and Commonwealth Foundation.

[Table: see text]

Pregabalin for hot flashes in women: NCCTG trial N07C1

9513

Background: Hot flashes are a major problem in many women for which better treatment options are needed. Given the known efficacy of gabapentin for decreasing hot flashes, it was decided to evaluate pregabalin, with hopes that it would work better and/or with fewer toxicities. Methods: A three-arm, double-blinded, placebo-controlled randomized trial was developed. Women with bothersome hot flashes (at least 28/week) were randomized to receive either a placebo or target pregabalin oral doses of 75 mg bid or 150 mg bid (starting at 50 mg/d and then increasing the dose at weekly intervals to 50 mg bid, then 75 mg bid, and then, in the higher dose arm, 150 mg bid); patients were treated for 6 weeks. Hot flash numbers and scores (hot flash number times mean severity) were measured using a validated daily hot flash diary. A one-week baseline period preceded initiation of study tablets. The primary endpoint was the average intra-patient difference in hot flash score between baseline and week six, comparing the higher dose pregabalin arm and the placebo arm. With the planned sample size of 55 patients per arm, there was an 80% power and two-sided 5% Type I error rate to detect a difference of 0.54 standard deviations, or 1.08 hot flashes per day, or 2.7 units of hot flash score per day. Results: 207 patients were randomized between 6/20/2008 and 8/21/2008. The study arms were well balanced. Mean/median daily hot flash scores and frequencies for all pts at baseline were 15.7/13.4 and 8.3/7.7, respectively. The table shows the decreases in hot flashes from the baseline to the sixth treatment week. Larger numbers illustrate greater hot flash reductions. Toxicity information, quality of life information, and information regarding the effects of hot flashes on subjective symptoms will be available at the meeting time. Conclusions: Pregabalin reduces hot flashes in women. There appears to be similar effects with both studied doses.

[Table: see text]

No significant financial relationships to disclose.

A randomized controlled trial evaluating a topical treatment for chemotherapy-induced neuropathy: NCCTG trial N06CA

9531

Background: Chemotherapy induced peripheral neuropathy (CIPN) is a prevalent dose limiting toxicity for several important cancer treatment agents. CIPN can impair function and cause distress. There are no proven pharmacologic treatments for established CIPN currently. This double blind randomized placebo controlled trial evaluated a compounded topical gel for this problem. The novelty of this treatment is that it might incorporate several agents with different mechanisms of action to provide relief locally without negative systemic effects. Methods: Patients with CIPN (rated ≥4 out of 10) for at least one month, related to previous and/or concurrent exposure to neurotoxic agents, were randomized to baclofen 10 mg, amitriptyline HCL 40 mg and ketamine 20 mg in a pluronic lecithin organogel (BAK-PLO) vs placebo (PLO) to determine its effect on numbness, tingling, pain, and motor function. Exclusion criteria included other causes and/or current treatment for peripheral neuropathy. The primary endpoint was the baseline adjusted sensory subscale of the EORTC QLQ-CIPN20, at 4 weeks. Results: Between February and May 2008, 208 patients were enrolled onto this trial. Four week data are shown in the table below, higher numbers being better. The percentage of patients that had improvements of at least 10, on a 100 point scale, in the motor subscale was statistically significantly higher in the BAK-PLO arm, p=.04. There were no unwanted toxicities associated with the BAK-PLO that were significantly different from placebo and no evidence of CNS or systemic toxicity. Conclusions: Topical treatment with BAK-PLO appears to moderately improve symptoms of CIPN. This topical gel was well tolerated without systemic side effects.

[Table: see text]

No significant financial relationships to disclose.

Hot flash placebo responses: Related to baseline hot flash frequency?

9628

Background: As multiple treatments have been studied for the management of hot flashes in randomized, controlled trials, hot flash placebo responses have been quite variable across trials. Based on observations of trial reports, it was hypothesized that the magnitude of placebo effect might correlate with the number of baseline hot flashes in different studies. The current project examines the effect of the baseline hot flash frequency required for study participation and also the actual number of baseline hot flashes observed as these individually relate to the eventual reductions of hot flash frequency observed in patients receiving placebos. Methods: Data were collected from placebo-controlled, double-blinded, randomized trials, identified by a PubMed search, which reported hot flash frequency at baseline, 4–6 weeks and 12 weeks. Trials were excluded if they had less than 20 participants completing the placebo arm. Data gathered, in each study, included the number of hot flashes required to enroll in the study, the average hot flash number during the baseline period, and the hot flash changes in the placebo arms of each study (percent reduction from the baseline period). A simple statistical analysis was conducted in a descriptive fashion since standard deviation was not available in many trials. Scatter plots and Pearson's correlation coefficients demonstrated the relationships between the placebo hot flash percent reduction from baseline and both the minimum required number of hot flashes at baseline, and the mean number of hot flashes at baseline. Results: 45 trials with 49 placebo arms were included in this analysis. A significant positive correlation was seen between the number of hot flashes required to enroll in a study and the percent reduction of hot flashes from baseline at 4–6 weeks (Rho = 0.481, p = 0.003). There was also a significant positive correlation between the number of hot flashes at baseline and the percent reduction of hot flashes from baseline at 4–6 weeks (Rho = 0.481, p= 0.002) and at 12 weeks (Rho = 0.573, p= 0.003). Conclusions: These data support that higher baseline hot flash enrollment requirements and also higher baseline hot flash frequencies are associated with an increased placebo response.

No significant financial relationships to disclose.

A phase I study of lapatinib and topotecan in patients with solid tumors

3598

Background: Drug resistance to topotecan can be the result of BCRP/ABCG2 expression. BCRP is a member of the ABC transporter family that pumps anticancer drugs out of the cell. Lapatinib is a potent and selective dual inhibitor of epidermal growth factor receptor (EGFR or ErbB1) and ErbB2 (Her2/Neu). 4-aminoquinazoline tyrosine kinase inhibitors have been shown to enhance the cytotoxicity of topotecan through inhibition of BCRP-mediated drug efflux in cancer cells. Methods: Thirty-seven patients with advanced stage cancers were enrolled at escalating dose levels of lapatinib and topotecan in cohorts IA, IB and IIB (MTD). Treatment schedule included lapatinib (750 - 1500 mg/d) daily for 21 (cohort IA) or 28 days (cohort IB) and topotecan (2.4 - 4.0 mg/ m2), days 1, 8 and 15; cycles were repeated every 28 days. Three patients were treated at each dose level, 18 on cohort IA, 9 on cohort IB and 10 at MTD (cohort IIB). Assessments of toxicity were performed with each cycle and clinical response was determined per RECIST criteria every other cycle. Results: The MTD for cohorts IA and IB was reached at a dose of 1250 mg of lapatinib and 3.2 mg/m2 of IV topotecan on days 1, 8 and 15. No DLT were seen during the dose escalation stage of cohorts IA and IB. Ten patients were enrolled at the MTD. There were no grade 4+ events. Thirteen grade 3+ events, considered to be related to treatment, were seen in 6 patients. The most common grade 3+ toxicities included dehydration (2) diarrhea (2), nausea (3), vomiting (2), neutropenia (1), thrombocytopenia (1), and fatigue (1). No abnormalities in left ventricular ejection fraction were noted. Stable disease was seen in 46% of the 37 patients. Conclusions: The combination of lapatinib and topotecan is a well-tolerated regimen. The MTD for the combination is lapatinib 1,250 mg orally once daily for 21 or 28 days and topotecan 3.2 mg/m2 on days 1, 8 and 15. Pharmacokinetic analysis for drug interaction will be available for presentation at the meeting. Supported in part by GSK and Mayo Clinic

No significant financial relationships to disclose.

Phase I/II trial of CCI-779 and bevacizumab in stage IV renal cell carcinoma: Phase I safety and activity results

5034

Background: The mammalian target of rapamicin (mTOR) and vascular endothelial growth factor (VEGF) pathways are critically involved in the pathogenesis and progression of clear cell renal cell carcinoma. Methods: The goal of the phase I portion of the trial was to determine the maximum tolerated dose (MTD) and dose limiting toxicity (DLT) of the combination of the mTOR inhibitor CCI-779 (C) and the anti-VEGF monoclonal antibody Bevacizumab (B). Patients with measurable stage IV clear cell RCC, performance status 0–2 and good organ function were eligible. Up to two prior treatment regimens were allowed. Treatment consisted of 25 mg IV weekly C and escalating IV doses of B (level 1= 5 mg/kg; level 2= 10 mg/kg) every other week. A cycle was defined as 4 weeks. Results: A total of 10 male and 2 female patients, median age 66 yrs (50–77) were enrolled to the phase I portion of the trial. PS: 0/1= 6/6; prior nephrectomy = 10; prior systemic therapy = 7 (prior cytokine therapy = 6); Number of metastatic sites: 1/2/≥3 = 2/2/8; one patient (out of 6) in dose level 1 experienced DLT which consisted of grade 3 hypertriglyceridemia. 1/6 patient in dose level 2 experienced DLT with grade 3 mucositis. Other grade 3 toxicities that were not DLTs included hypertension, proteinuria, hemorrhage, nausea/vomiting, dehydration, anorexia, pneumonitis, anemia, and hypophosphatemia. The best responses in the 12 evaluable patients included 7 PRs and 3 SDs. One patient had PD due to symptomatic deterioration and in one patient response information is not available at the time of this submission. Conclusions: Combination therapy with CCI-779 and Bevacizumab is safe and shows promising clinical antitumor activity. The recommended phase II dose is CCI-779 25 mg/week with bevacizumab 10 mg/kg every other week. The phase II study in stage IV renal cell cancer patients refractory to FDA approved receptor tyrosine kinase inhibitors is under way. The goals of the phase II portion are to determine the proportion of patients who have not had disease progression at 6 months, safety, response rates and correlative biomarker studies including determination of the tumor’s VHL-HIF-VEGF status, PTEN/AKT expression, plasma angiogenic activity and angiogenic cytokines. Supported by NCI N01-CM-62205

No significant financial relationships to disclose.

The effect of ischemic re-perfusion injury plus particle infusion embolism on the apoptosis of rats with pancreatic cancer

OBJECTIVES

In an attempt to develop new method of treating the end- or mid-stage pancreatic cancer, we examined the effect of ischemic re-perfusion injury plus particle embolism on the pathology and cell apoptosis of pancreatic cancer in Sprague Dawely rats.

METHODS

9 mg dimethylbeneanthracine (DMBA) were implanted directly into the parenchyma of pancreatic tail of Sprague-Dawely rats. After establishment of tumor, the inferior splenic artery, a main supplying vessel to pancreatic tail was subjected to blockade and re-opening for 30 min separately, then embolism particles were infused via the artery. Afterwards, artery was ligated. Pathological changes and cell apoptosis indicators (AI) of pancreatic cancer were observed by light microscopy and ISEL respectively 14 days after the operation.

RESULTS

The prevalence of pancreatic cancer among DMBA-implanted rats evaluated 3 months to 4 months after implantation was 59%. The volumes of the tumor in positive control group (B), pancreatic ischemic group (C), pancreatic ischemic re-perfusion injury group (D) were significantly larger than pancreatic ischemic re-perfusion injury plus particle thrombus group (E) ( P < 0.01). The volumes of the tumor in groups D, E were significantly smaller than that in group C (P < 0.01). There was a significant difference in tumor size between group B and group C ( P < 0. 01), but the difference was not significant between group D and group E ( P > 0.05). There was a significant infiltration of tumor tissue in group B rats, but strong inflammatory reaction was not noted. In groups C, D, E, a localized tumor growth was observed; infiltration of inflammatory cells and proliferation of fibroblasts and connective fiber were obvious, and some of these fibers grew into cancer nests and separate the tumor. The above findings were most conspicuous in group E. There was a significant difference in AI between group E (13.7 +/- 1.5) and other groups ( P < 0.01), with the difference being also significant between group C (4.3 +/- 2.4), D (8.5 +/- 1.1) and group B (1.2 +/- 0.8) (P < 0.01), and between group C and group D (P < 0.01) or between group D and group E ( P < 0.01). In the samples of group A, the apoptotic cells were not found.

CONCLUSIONS

Pancreatic ischemic re-perfusion injury plus particle thrombus can cause significant infiltration of inflammatory cells in tumor tissues thereby limiting its growth, and inducing cell apoptosis of pancreatic cancer. This effect is superior to either pancreatic ischemia alone or pancreatic ischemia plus re-perfusion injury.