LY293111 improves efficacy of gemcitabine therapy on pancreatic cancer in a fluorescent orthotopic model in athymic mice

Pancreatic cancer has an abysmal prognosis because of late diagnosis and lack of effective therapeutics. New drugs are desperately needed. The present study determined the effect of the LTB4 receptor antagonist, LY293111, on tumor growth and metastases in a fluorescent orthotopic model of pancreatic cancer. Pancreatic cancer cells (S2-013) with stable expression of enhanced green fluorescent protein were implanted into the duodenal pancreatic lobe of athymic mice. Animals were allocated to four groups (eight mice per group): control (no treatment); LY293111; gemcitabine; and LY293111 + gemcitabine. Monitoring of the surgical procedure and follow-up examinations at 2, 3, and 4 weeks after implantation to monitor tumor growth and metastases were performed using a fluorescence microscope and the reversible skin-flap technique. A staging and scoring system was developed to evaluate tumor progression, based on the TNM classification. Control animals developed end-stage disease with invasive cancer, metastases, and cachexia. Tumor growth and incidence of metastases were significantly reduced in all treated mice. However, combined treatment with LY293111 and gemcitabine was most effective. LY293111 is a novel therapeutic agent for pancreatic cancer, which improves the efficacy of gemcitabine. It is well tolerated and can be administered orally and, therefore, provides a new hope for patients suffering from pancreatic adenocarcinoma.     

Concurrent gemcitabine and radiotherapy with and without neoadjuvant gemcitabine for locally advanced unresectable or resected pancreatic cancer: a phase I-II study

PURPOSE: To determine the safety, efficacy, and tolerability of biweekly gemcitabine with concurrent radiotherapy (RT) for resected and locally advanced (LA) pancreatic cancer. METHODS AND MATERIALS: Eligible patients had either LA or resected pancreatic cancer. Between March 1999 and July 2001, 63 patients (31 with LA and 32 with resected disease) were treated. Of the 63 patients, 28 were enrolled in a Phase I study of increasing radiation doses (35 Gy [n = 7], 43.75 Gy [n = 11], and 52.5 Gy [n = 10] given within 4, 5, or 6 weeks, respectively, in 1.75-Gy fractions) concurrently with 40 mg/m(2) gemcitabine biweekly. Subsequently, 35 were enrolled in a Phase II study with the addition of induction gemcitabine 1000 mg/m(2) within 7 or 8 weeks to concurrent biweekly gemcitabine (40 mg/m(2)) and 52.5 Gy RT within 6 weeks. RESULTS: In the LA population, the best response observed was a complete response in 1, partial response in 3, stable disease in 10, and progressive disease in 17. In the phase II trial, gemcitabine plus RT was not delivered to 8 patients because of progression with induction gemcitabine alone (n = 5) or by patient request (n = 3). On intent-to-treat analysis, the median survival in the LA patients was 13.9 months and the 2-year survival rate was 16.1%. In the resected population, the median progression-free survival was 8.3 months, the median survival was 18.4 months, and the 2- and 5-year survival rate was 36% and 19.4%, respectively. The treatment was well tolerated; the median gemcitabine dose intensity was 96% of the planned dose in the neoadjuvant and concurrent portions of the Phase II study. No treatment-related deaths occurred. CONCLUSION: Biweekly gemcitabine (40 mg/m(2)) concurrently with RT (52.5 Gy in 30 fractions of 1.75 Gy) with or without induction gemcitabine is safe and tolerable and shows efficacy in patients with LA and resected pancreatic cancer.     

Antiangiogenic treatment with three thrombospondin-1 type 1 repeats versus gemcitabine in an orthotopic human pancreatic cancer model.

PURPOSE: In this study, we investigated the antitumor efficacy of thrombospondin-1 three type 1 repeats (3TSR), the antiangiogenic domain of thrombospondin-1, in comparison and in combination with gemcitabine, in an orthotopic pancreatic cancer model. EXPERIMENTAL DESIGN: Human pancreatic cancer cells were injected into the pancreas of severe combined immunodeficient mice. The animals were treated with 3TSR, gemcitabine, 3TSR plus gemcitabine, or vehicle for 3 weeks. Subsequently, the effects of 3TSR and/or gemcitabine on tumor growth, tumor necrosis, microvessel density, cancer cell proliferation, apoptosis, and endothelial cell apoptosis were analyzed. RESULTS: After 3 weeks of treatment, 3TSR reduced tumor volume by 65%, and gemcitabine by 84%. Tumor volume was not statistically different between gemcitabine group and combinatorial treatment group. Extensive necrotic areas were observed in tumors from 3TSR-treated mice, whereas tumors from gemcitabine and combinatorially treated mice were less necrotic than control tumors. 3TSR reduced tumor microvessel density and increased tumor blood vessel endothelial cell apoptosis. In contrast, gemcitabine induced apoptosis and inhibited proliferation of cancer cells. CONCLUSION: 3TSR, the antiangiogenic domain of thrombospondin-1, showed comparable antitumor efficacy to gemcitabine in a human pancreatic cancer orthotopic mouse model. No synergistic effect was found when the two drugs were combined and possible reasons are discussed in detail. A delicate balance between normalization and excessive regression of tumor vasculature is important when initiating alternative combinatorial regimens for treatment of patients with pancreatic cancer.     

Combination of a monoclonal anti-phosphatidylserine antibody with gemcitabine strongly inhibits the growth and metastasis of orthotopic pancreatic tumors in mice

Pancreatic cancer continues to have a dismal prognosis and novel therapy is needed. In this study, we evaluate a promising new target for therapy, phosphatidylserine (PS). PS is an anionic phospholipid located normally on the inner leaflet of the plasma membrane in mammalian cells. In the tumor microenvironment, PS becomes externalized on vascular endothelium. The monoclonal antibody 3G4 binds PS and promotes an inflammatory response against tumor blood vessels, resulting in reduction of tumor growth. Mice with orthotopic pancreatic tumors were treated with 3G4, gemcitabine or a combination of both drugs. Tumor burden including pancreas weight and metastatic lesions (liver, lymph node and peritoneal) were reduced 3- to 5-fold by the combination therapy as compared with 1.5- to 2-fold with 3G4 and gemcitabine alone, respectively. Treatment of tumor-bearing animals with the combination therapy increased macrophage infiltration into the tumor mass 10-fold and reduced microvessel density in the tumor by 2.5-fold compared with tumors from untreated animals. Gemcitabine alone and 3G4 alone were less effective than the combination of the 2 agents together. The additive therapeutic effect of both agents appears to be because chemotherapy increases PS exposure on tumor vascular endothelium and amplifies the target for attack by 3G4. In conclusion, 3G4 enhanced the anti-tumor and anti-metastatic activity of gemcitabine without contributing to toxicity.     

Role of postoperative adjuvant chemotherapy with gemcitabine for pancreatic cancer: feasibility and anti-tumor effect

BACKGROUND: The feasibility and anti-tumor activity of gemcitabine in postoperative adjuvant chemotherapy were evaluated retrospectively. PATIENTS AND METHODS: Sixteen patients with advanced pancreatic cancer, who had a pancreatic resection with curative intent over the three years up to February 2003, were enrolled in this study. Aggressive surgery with dissection of para-aortic nodes and nerves around the superior mesenteric and celiac artery was carried out. After the operation, all patients have been given biweekly administration of 1,000 mg/m2 gemcitabine for more than 12 courses. RESULTS: The chemotherapy was well tolerated with only mild symptomatic and hematologic toxicities. Grade 3 adverse effects were observed in only 3 patients (19%); nausea and vomiting in 1 patient and leucocytopenia in 2 patients. The disease-specific cumulative survival rates were 81% at 1 year and 47% at 2 years, with a median survival of 20.4 months. The median disease-free interval was 16.8 months in all patients. CONCLUSIONS: Adjuvant systemic chemotherapy utilizing gemcitabine was feasible with acceptable adverse effects. Gemcitabine is a promising agent for the treatment of resectable advanced pancreatic cancer, and a randomized control trial is warranted for gemcitabine-based chemotherapy.     

The role of second-line chemotherapy after gemcitabine failure in patients with advanced pancreatic cancer

Systemic chemotherapy with single-agent gemcitabine or a gemcitabine-based regimen still remains a standard of care for the treatment of patients with locally advanced and metastatic pancreatic cancer. To date, no standard treatment approach for patients that show progressive disease during gemcitabine therapy is defined. Several clinical trials have evaluated the safety and efficacy of second-line chemotherapy after gemcitabine failure in this patient population. Based on the currently available data, there is increasing evidence that selected patients may derive clinical benefit from salvage chemotherapy, also with regard to survival. However, results from large randomized Phase III trials are still lacking and therefore no evidence-based treatment recommendation can be given for patients with advanced pancreatic cancer after failure of first-line gemcitabine.     

Second-line chemotherapy with pemetrexed after gemcitabine failure in patients with advanced pancreatic cancer: a multicenter phase II trial.

BACKGROUND: A standard second-line chemotherapy regimen has yet to be defined for patients with gemcitabine (Gem)-refractory advanced pancreatic cancer (PC). PATIENTS AND METHODS: In this multicenter phase II trial, patients with unresectable or metastatic PC who had progressed on single-agent Gem or a Gem-containing regimen received pemetrexed 500 mg/m(2) as a 10-min infusion every 3 weeks until disease progression or occurrence of unacceptable toxicity. The primary end point was the 3-month survival rate. RESULTS: A total of 192 treatment cycles were given to 52 patients. The overall response rate was 3.8% (two partial responses); 10 patients (19.2%) experienced stable disease, nine of them for >12 weeks. At least one CA 19-9 reduction > or =50% occurred in 12 patients (23.1%). The 3-month survival rate was 75% (95% confidence interval 63.2% to 86.8%), the median time to tumor progression was 7 weeks (range 1-62 weeks) and the median overall survival time was 20 weeks (range 1-84 weeks). Grade 3/4 hematological toxic effects included (percent of patients): neutropenia (17.3%), thrombocytopenia (5.8%) and anemia (3.8%). The most frequent non-hematological toxic effects were diarrhea, nausea and stomatitis/pharyngitis (23.1% each). CONCLUSION: Pemetrexed is a safe treatment option with moderate activity in patients with advanced PC after failure of Gem.     

Resveratrol,a multitargeted agent,can enhance antitumor activity of gemcitabine in vitro and in orthotopic mouse model of human pancreatic cancer

Gemcitabine, while a standard treatment of advanced pancreatic cancer (PaCa), alone is not very effective. New agents that are safe and effective are highly needed. Resveratrol is one such agent which is safe and multitargeted; and has been linked with suppression of survival, proliferation, invasion and angiogenesis of cancer. Whether resveratrol can sensitize PaCa to gemcitabine in vitro and in vivo was investigated. We established PaCa xenografts in nude mice, randomized into 4 groups, and treated with vehicle, gemcitabine, resveratrol and with combination. Modulation of NF‐κB and markers of proliferation, angiogenesis and invasion were ascertained using electrophoretic mobility shift assay (EMSA), immunohistochemistry and western blot analysis. Resveratrol inhibited the proliferation of 4 different human PaCa cell lines, synergized the apoptotic effects of gemcitabine, inhibited the constitutive activation of NF‐κB and expression of bcl‐2, bcl‐xL, COX‐2, cyclin D1 MMP‐9 and VEGF. In an orthotopic model of human PaCa, we found that resveratrol significantly suppressed the growth of the tumor (p < 0.001) and this effect was further enhanced by gemcitabine (p < 0.001). Both the markers of proliferation index Ki‐67 and the micro vessel density CD31 were significantly downregulated in tumor tissue by the combination of gemcitabine and resveratrol (p < 0.001 vs. control; p < 0.01 vs. gemcitabine). As compared to vehicle control, resveratrol also suppressed the NF‐κB activation and expression of cyclin D1, COX‐2, ICAM‐1, MMP‐9 and survivin. Overall our results demonstrate that resveratrol can potentiate the effects of gemcitabine through suppression of markers of proliferation, invasion, angiogenesis and metastasis.     

A case of drug-induced interstitial pneumonitis after adjuvant chemotherapy with gemcitabine for pancreatic cancer

We present a case of interstitial pneumonitis induced by gemcitabine. The patient was a 48-year-old male who underwent pancreaticoduodenectomy with portal vein resection for ductal adenocarcinoma of the pancreas head. Twenty-two days after operation, adjuvant chemotherapy with gemcitabine(1,000 mg/m(2) on days 1, 8 and 15 every 4 weeks)was started. During three courses of chemotherapy, no adverse event of WHO grade 2 or more was observed. Seven days after the last infusion, fever and consciousness disorder emerged without respiratory symptoms. Arterial blood gas analysis revealed severe hypoxemia. Chest X-ray and CT showed diffuse bilateral interstitial infiltrates. Oxygenation and respiratory support were immediately given, and steroid pulse therapy with 1,000 mg/day of methylprednisolone was started. His symptoms and radiolographical findings were dramatically improved. The patient could be discharged on the 14th day after admission. Acute pulmonary toxicity induced by gemcitabine is rare, but could lead to severe complications. The review of reported cases showed the effectiveness of corticosteroid therapy for pulmonary toxicity due to the agent.     

A case of salvage chemotherapy with gemcitabine hydrochloride and nedaplatin for gemcitabine-refractory pancreatic cancer

A 73-year-old woman with carcinoma of the pancreatic head underwent Whipple?s operation and intraoperative radiation therapy(20 Gy). After surgery, adjuvant chemotherapy with gemcitabine hydrochloride(GEM 1,000 mg every two weeks)was conducted. After 15 courses, the tumor marker CA19-9 gradually increased to 3,770 U/mL, and a supraclavicular lymph node metastasis(Virchow?s node)was detected. We selected the combination of GEM and nedaplatin(1,000 mg and 50 mg every two weeks, respectively)as salvage chemotherapy. After six courses of this nedaplatin/GEM combination, her CA19-9 level was markedly reduced to 657 U/mL and the lymph node metastasis disappeared. There were no adverse reactions. Combined nedaplatin/GEM therapy was continued for nine months(18 courses)until lung metastases occurred. This combination can be effective in some patients with GEM-refractory pancreatic cancer.     

Feasibility and anti-tumor activity of postoperative adjuvant chemotherapy with gemcitabine for resected pancreatic cancer

The feasibility and anti-tumor activity of gemcitabine (GEM) as postoperative adjuvant chemotherapy were evaluated retrospectively. Between September 1998 and June 2007, patients with resected invasive pancreatic cancer (stage III, IVa, IVb) were given adjuvant chemotherapy with GEM (GEM group, n=10) or did not receive chemotherapy (n=11). Started the administration of GEM 38.5 days after surgery, and the mean duration was 15.4 months. Grade 3 or 4 adverse event was not observed in the GEM group. There was a significant difference in overall survival between the GEM group and the no-chemotherapy group (p=0.037), but there was no significant difference in disease-free survival between the two groups. Adjuvant chemotherapy with GEM was feasible and showed a benefit in patients with invasive pancreatic cancer.     

Wortmannin inhibits pkb/akt phosphorylation and promotes gemcitabine antitumor activity in orthotopic human pancreatic cancer xenografts in immunodeficient mice.

Pancreatic cancer is resistant to almost all classes of cytotoxic agents. Gemcitabine seems to be the current drug of choice. We have recently reported that inhibition of the phosphatidylinositide 3-kinase-protein kinase B (PKB/Akt) cell survival pathway by wortmannin enhances gemcitabine-induced apoptosis in cultured human pancreatic cancer cells (1). The present study investigated the effects of wortmannin on orthotopic human pancreatic cancer xenografts implanted in severe combined immunodeficient mice. Animals were given single i.v. bolus injections of 0.175, 0.35, or 0.7 mg/kg of wortmannin and killed at 0.5, 1, 2, or 4 h after treatment. Phosphorylated PKB/Akt levels in tumor tissues were measured by fluorescence image analysis. Wortmannin was found to inhibit PKB/Akt phosphorylation in a time- and dose-dependent manner, reaching a plateau at 4 h and at 0.7 mg/kg. The levels of phosphorylated PKB/Akt were maximally decreased by approximately 50% relative to the vehicle control. Subsequently, the extent of apoptosis in tumors treated with gemcitabine or wortmannin alone or in combination was determined using terminal deoxynucleotidyl transferase-mediated nick end labeling assay and computerized image analysis. Orthotopic tumors exposed to 80 mg/kg gemcitabine for 48 h and then 0.7 mg/kg wortmannin for 4 h showed a 5-fold increase (P = 0.002) in apoptosis compared with those treated with each agent alone and with the vehicle control. The combination treatment also significantly (P < 0.001) inhibited tumor growth. Taken together, our findings support the potential of phosphatidylinositide 3-kinase inhibitors as adjuncts to conventional chemotherapy in the treatment of pancreatic cancer.     

吉西他滨单药化疗与联合化疗治疗进展期胰腺癌的疗效观察

目的观察比较吉西他滨单药与联合化疗治疗进展期胰腺癌的疗效。方法回顾性分析了大连医科大学附属一院2002年至2009年收治的45例进展期胰腺癌患者的临床资料,吉西他滨单药组17例,剂量为1000mg/m2,d1、8,三周为一周期;吉西他滨联合治疗组28例,联合化疗方案包括吉西他滨1000mg/m2,d1、8,分别联合：（1）氟尿嘧啶425～600mg/m2,静滴或持续静脉泵入,d1～5;（2）顺铂60～75mg/m2,分3～4d静脉滴入;（3）奥沙利铂85～130mg/m2,d1,静脉滴入;（4）卡培他滨1000mg/m2,每天两次口服,d1～14。21d为一周期。采用Kaplan-Meier生存曲线分析患者的生存期,并比较两组间的临床受益率、中位疾病进展时间、中位生存时间及不良反应。结果吉西他滨联合组及单药组的临床收益率均得到提高,但两组间比较临床受益率、疾病控制率、中位生存时间均无统计学意义。结论吉西他滨联合化疗方案与吉西他滨单药治疗进展期胰腺癌相比,疗效、临床受益率、中位生存期均相似。     

手术加吉西他滨为主的化疗方案治疗胰腺癌56例

目的:探讨手术加吉西他滨为主的化疗方案治疗胰腺癌的临床效果。方法:对我院自2001年3月～2003年3月收治的中晚期胰腺癌病人56例,采用姑息手术加泵植入区域化疗健择为主的化疗方案进行治疗。结果:行姑息手术加术后以健择为主的化疗方案的患者,分别生存0.5～3年,中位生存期19个月。复发和转移率19.64%,未出现治疗相关死亡及IV度不良反应。结论:该方法治疗中晚期胰腺癌有效、安全和低毒,值得临床进一步推广应用。     

手术加吉西他滨为主的化疗方案治疗胰腺癌56例

目的：探讨手术加吉西他滨为主的化疗方案治疗胰腺癌的临床效果。方法：对我院自2001年3月～2003年3月收治的中晚期胰腺癌病人56例,采用姑息手术加泵植入区域化疗健择为主的化疗方案进行治疗。结果：行姑息手术加术后以健择为主的化疗方案的患者,分别生存0.5～3年,中位生存期19个月。复发和转移率19.64%,未出现治疗相关死亡及IV度不良反应。结论：该方法治疗中晚期胰腺癌有效、安全和低毒,值得临床进一步推广应用。     

吉西他滨联合替吉奥化疗在胰腺癌根治术后患者中的应用

目的探讨吉西他滨联合替吉奥化疗在胰腺癌根治术患者术后的疗效。方法选取2012年4月至2014年3月间大连市第三人民医院收治的72例胰腺癌根治术后患者,采用随机数字表法随机分为观察组和对照组,每组36例。观察组患者采用吉西他滨联合替吉奥化疗,对照组患者采用吉西他滨联合奥沙利铂化疗。比较两组患者临床疗效、临床受益率、不良反应、1年内死亡率和治疗前后生活质量的差异。结果两组患者的有效率和疾病控制率方面差异无统计学意义(P>0.05)。观察组患者临床受益率高于对照组,组间差异有统计学意义(P<0.05)。观察组患者不良反应发生率较对照组低,差异有统计学意义(P<0.05)。两组患者1年内死亡率差异无统计学意义(P>0.05)。治疗前,两组患者生活质量评分差异无统计学意义(P>0.05)。治疗后,观察组生活质量得分高于对照组,组间差异有统计学意义(P<0.05)。结论吉西他滨联合替吉奥化疗可有效提高胰腺癌患者根治术后的临床受益,并减少不良反应,改善生活质量。     

Serum amyloid A as a tumor marker in sera of nude mice with orthotopic human pancreatic cancer and in plasma of patients with pancreatic cancer

We screened an orthotopic nude mouse model of human pancreatic cancer for candidate serum biomarkers and examined their presence in the plasma of pancreatic cancer patients. Nude mice were injected in the pancreas with L3.9pl human pancreatic cancer cells. One week later, the mice were randomized into 4 treatment groups: i) control, saline; ii) oral STI 571; iii) intraperitoneal gemcitabine; and iv) STI 571 and gemcitabine. After 1, 2, and 3 weeks of treatment, sera and tumors were collected from mice in each group as well as uninjected mice. All sera were analyzed by surface enhanced laser desorption ionization mass spectrometry using ProteinChip technology. Protein profiles were analyzed with the Biomarker Wizard software package. The concentration of candidate proteins was evaluated in mouse sera and plasma from 135 pancreatic cancer patients, 7 pancreatitis patients, and 113 healthy volunteers. The combination therapy inhibited tumor growth. A 11.7-kDa protein peak correlating with tumor weight was purified by gel filtration, separated by SDS-PAGE, and identified as mouse serum amyloid A (SAA) by amino acid sequencing and public database searches. The expression of SAA in mouse sera was confirmed by Western blotting and correlated with tumor weight. The level of SAA in plasma of pancreatic cancer patients correlated with clinical stage and was significantly higher than in normal volunteers (mean value: 180.1 microg/ml vs 27.9 microg/ml: P<0.01) or pancreatitis patients. For SAA used as a single tumor marker with a cut-off of 75 microg/ml, the sensitivity for pancreatic cancer was 96.5% and specificity was 31.9%. Our search for specific marker proteins to identify pancreatic cancer was unsuccessful. Although SAA is not specific for pancreatic cancer and not sensitive enough to detect stage I patients, it may be a candidate biomarker for detecting and monitoring the progressive growth of pancreatic cancer.     

Low‐dose gemcitabine depletes regulatory T cells and improves survival in the orthotopic Panc02 model of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive human neoplasms with extremely poor prognosis and a low survival rate. Immunosuppressive cell populations, e.g. regulatory T cells (Treg), appear to be important in PDAC, contributing to patient's poor prognosis. Therefore, we investigated the PDAC microenvironment with a focus on conventional and regulatory T cells in view of their potential therapeutic importance. We found that tumors from the murine Panc02 orthotopic model of PDAC were infiltrated with high numbers of Treg. Remarkably, these cells exhibited the effector/memory phenotype, suggesting their enhanced suppressive activity and higher proliferation capacity. Although we observed a steady increase in transforming growth factor‐β (TGF‐β) levels in the tumors, treatment with a specific inhibitor of TGF‐β receptor I kinase failed to abrogate Treg accumulation. A CCR4 antagonist did not affect Treg percentage in the tumor either. However, intense Treg cell division in the tumor microenvironment was demonstrated, suggesting local proliferation as a major mechanism of Treg accumulation in PDAC. Notably, this accumulation was reduced by low‐dose gemcitabine administration, resulting in a modestly increased survival of PDAC mice. Our results provide an insight into mechanisms of immunosuppression in PDAC, suggesting an important role for proliferative expansion of effector/memory Treg. Low‐dose gemcitabine therapy selectively depletes Treg, providing a basis for new modalities of PDAC therapy.