Experimental evidence of good efficacy and reduced toxicity with peptide-doxorubicin to treat gastric cancer.

BACKGROUND: To compare the efficacy and toxicity of peptide-doxorubicin (PDOX) and doxorubicin (DOX) on nude mice models of human gastric cancer. RESULTS: Both PDOX and DOX could significantly inhibit tumor growth compared with Control (P < 0.05) in both subcutaneous and orthotopic models. Animal survival was much better in PDOX group than DOX group. In peripheral blood test, PDOX group had significantly higher levels of platelets than the Control (P < 0.05), and lymphocyte lower than Control (P < 0.05). There were no significant differences on liver, kidney and cardiac function parameters among three groups (P > 0.05). Immunohistochemistry showed that treatment groups had much higher Tunel than Control (P < 0.05), and PDOX had significantly lower Ki-67 than doxorubicin and Control group (P < 0.01). Western blotting showed that PDOX caused much higher expressions of P53, P21, Aparf-1, pro- and cleaved-caspase 3, compared with DOX. CONCLUSION: Compared with DOX, PDOX has increased effects but much decreased toxicity in treating animal model of gastric cancer. MATERIALS AND METHODS: Animals in subcutaneous model were randomized into Control, doxorubicin, PDOX-L, PDOX-M, and PDOX-H groups. Animals in surgical orthotopic implantation model were randomized into Control, doxorubicin and, peptide-doxorubicin groups. The animals were treated, monitored and examined following a set protocol.

Anti-cancer effects of novel doxorubicin prodrug PDOX in MCF-7 breast cancer cells.

Ac-Phe-Lys-PABC-DOX (PDOX) is a smart doxorubicin (DOX) prodrug designed to decrease toxicities while maintaining the potent anticancer effects of DOX. This study was aimed at elucidating the effectiveness and toxicities of DOX and PDOX in patient-derived MCF-7 breast cancer cells in vitro. The MCF-7 cells were exposed to both PDOX and DOX, and cytotoxicities, cell cycle and P53/P21 signaling alterations were studied. Abundant cathepsin B was found in the MCF-7 cells, and treatment with PDOX and DOX triggered dose- and time-dependent cytotoxicity and resulted in a significant reduction in cell viability. The IC50 of PDOX and DOX was 3.91 and 0.94 µmol/L, respectively. Both PDOX and DOX caused an up-regulation of the P53/P21-related signal pathway, and PDOX significantly increased expression of P53 and caspase 3, and arrested the cell cycle at the G1/G2 phase. As compared with DOX, PDOX reduced toxicities, and it may have different action mechanisms on breast cancer cells.

Synthesis, identification and in vivo studies of tumor-targeting agent peptide doxorubicin (PDOX) to treat peritoneal carcinomatosis of gastric cancer with similar efficacy but reduced toxicity.

BACKGROUND: This work aimed to synthesize a cathepsin B (CTSB)-cleavable tumor-targeting prodrug peptide doxorubicin (PDOX) and study the in vivo efficacy and toxicities on an animal model of gastric peritoneal carcinomatosis (PC). METHODS: PDOX was synthesized using doxorubicin (DOX) attaching to a CTSB-cleavable dipeptide Ac-Phe-Lys and a para-amino-benzyloxycarbonyl (PABC) spacer. PC model was established by injecting VX2 tumor cells into the gastric sub-mucosa of 40 rabbits, which then were randomized into 4 groups: the Control (n = 10) without treatment, the HIPEC (n = 10) receiving cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC), the PDOX (n = 10) and the DOX (n = 10) receiving systemic chemotherapy with PDOX 50.0 mg/kg or DOX 5.0 mg/kg, respectively, after CRS + HIPEC. RESULTS: The median overall survivals (OS) were 23.0 d (95% CI: 19.9 d - 26.1 d) in the Control, 41.0 d (36.9 d - 45.1 d) in the HIPEC, 65.0 d (44.1 d - 71.9 d) in the PDOX, and 58.0 d (39.6 d - 54.4 d) in the DOX. Compared with the Control, the OS was extended by 70% in the HIPEC (p < 0.001) and further extended by 40% in the DOX (p = 0.029) and by 58% in the PDOX (p = 0.021), and the PC severity was decreased in the HIPEC and further decreased in the PDOX and DOX. Animals receiving DOX treatment showed hematological toxicities with marked reduction of white blood cells and platelets, as well as cardiac toxicities with significant increases in creatine kinase mb isoenzyme, evident myocardium coagulation necrosis, significant nuclear degeneration, peri-nucleus mitochondria deletion, mitochondria-pyknosis, and abnormal intercalated discs. But these toxicities were not evident in the PDOX. CONCLUSIONS: PDOX is a newly synthesized tumor-targeting prodrug of DOX. Compared with DOX, PDOX has similar efficacy but reduced hematological and cardiac toxicities in treating rabbit model of gastric PC.

[Exploratory analysis of the effect of toxicity of sunitinib on the clinical outcome of patients with advanced renal cell carcinoma].

OBJECTIVE: To explore the effect of toxicity of sunitinib on the clinical outcome of patients with advanced renal cell carcinoma (RCC) . METHODS: A total of 136 patients with advanced RCC were treated with sunitinib from 2008 to 2011. There were 91 males and 45 females with an average age of 56 years. Their 6-week therapy cycle was 4 weeks of sunitinib 50 mg daily followed by 2-week off-treatment (schedule 4/2). The median follow-up time was 15 months. Correlation between toxicities and overall survival (OS) was evaluated in a Cox model using log-transformed levels after adjusting for MSKCC model.Log-rank test and Cox proportional hazard model were used to assess the value of drug toxicity as the prognostic factors. RESULTS: The increased hemoglobin on cycle 1 day 14 (HR:0.950, 95%CI:0.923-0.978) and the increased lymphocytes on cycle 1 days 28 and 42 (HR:0.405, 95%CI:0.203-0.809, HR:0.394, 95%CI:0.179-0.867) were significantly associated with OS (P adj = 0.001, 0.014 and 0.022 respectively). Hypertension class III/IV (HR:0.066, 95%CI:0.008-0.582), and the number of neutrophils screening and lymphocyte count ratio (HR:2.537, 95%CI:1.182-5.404) were the survival prognosis independent predictors. CONCLUSION: Early hematopoietic toxicities may potentially predict the outcomes of advanced RCC after a therapy of sunitinib.

Targeting therapy of hepatocellular carcinoma with doxorubicin prodrug PDOX increases anti-metastatic effect and reduces toxicity: a preclinical study.

BACKGROUND: This study was to investigate the effects and safety of cathepsin B-cleavable doxorubicin (DOX)-prodrug (PDOX) for targeting therapy of metastatic human hepatocellular carcinoma (HCC) using DOX as a positive control drug. METHODS: The orthotopic nude mice model of highly metastatic HCC was established and the animals were randomized and treated with PDOX, DOX and saline, respectively. Hematology, biochemistry and tumor markers were studied. At autopsy, liver tumor weight and size, ascites, abdominal lymph nodes metastases, experimental peritoneal carcinomatosis index (ePCI), and tumor-host body weight ratio were investigated. Immunohistochemical studies and western blotting were done to investigate key molecules involved in the mechanism of action. RESULTS: Compared with Control, both PDOX and DOX could similarly and significantly reduce liver tumor weight and tumor volume by over 40%, ePCI values, retroperitoneal lymph node metastases and lung metastases and serum AFP levels (P < 0.05). The PDOX group had significantly higher WBC than the DOX group (P < 0.05), and higher PLT than Control (P < 0.05). Serum BUN and Cr levels were lower in the PDOX group than DOX and Control groups (P < 0.05). Compared with Control, DOX increased CK and CK-MB; while PDOX decreased CK compared with DOX (P < 0.05). Multiple spotty degenerative changes of the myocardium were observed in DOX-treated mice, but not in the Control and PDOX groups. PDOX could significantly reduce the Ki-67 positive rate of tumor cells, compared with DOX and Control groups. PDOX produced the effects at least via the ERK pathway. CONCLUSION: Compared with DOX, PDOX may have better anti-metastatic efficacy and reduced side effects especially cardio-toxicities in this HCC model.

[Hematologic adverse effects in patients with renal cell carcinoma treated with sunitinib].

OBJECTIVE: To explore the hematologic adverse effects in patients with renal cell carcinoma treated with sunitinib. METHODS: A total of 136 patients with advanced renal cell carcinoma were treated with sunitinib at our hospital from 2008 to 2011. There were 91 males and 45 females with an average age of 55.5 years. They received sunitinib in repeated 6-week cycles consisting of 4 weeks of sunitinib 50 mg per day followed by 2 weeks of treatment (schedule 4/2). The hematologic toxicities, collected at baseline and 14, 28, 42 (after a 2-week rest period) days, were graded according to the National Cancer Institute common terminology criteria for adverse events version 3.0. The paired Wilcoxon test was used to evaluate the kinetics of hematologic adverse effects at days 14, 28, and 42 post-treatment. RESULTS: The hematologic toxicities included leukopenia (n = 91, 66.9%), neutropenia (n = 95, 69.8%), lymphopenia (n = 58, 46.2%), thrombopenia (n = 89, 65.4%) and hypohemoglobinemia (n = 48, 35.3%). Among them, 31 cases (22.8%) had the high-grade (including grades 3 and 4) toxicity of thrombopenia. There were depressions in hematopoietic cell populations including leukocytes, neutrophils, and platelets at days 14, 28 and 42 versus the baseline level (all P < 0.05). The median hemoglobin level transiently increased at days 14 and 28 (both P < 0.01) and returned to the level of baseline at days 42 (P = 0.754). CONCLUSIONS: The incidence of hematologic adverse effects of sunitinib slightly varies with what have been observed in previous studies. And the incidence of high-grade toxicity of thrombocytopenia is higher than that reported in studies conducted in the US and Europe.

Anticancer effects of Ac­Phe­Lys­PABC­doxorubicin via mitochondria­centered apoptosis involving reactive oxidative stress and the ERK1/2 signaling pathway in MGC­803 cells.

Ac­Phe­Lys­PABC­DOX (PDOX) is a smart doxorubicin (DOX) prodrug designed to decrease toxicities while maintaining the potent anticancer effects of DOX. The present study aimed to elucidate the molecular mechanisms of action of PDOX using MGC­803 gastric cancer cells as a model. The cells were treated with both PDOX and DOX, and cytotoxicities, cell cycle analysis, reactive oxygen species (ROS) generation, mitochondrial damage and ERK1/2 signaling pathway alterations were studied. Abundant cathepsin B expression was observed in the MGC­803 cells, and treatment with PDOX and DOX triggered dose­dependent cytotoxicity and resulted in a significant reduction in cell viability. IC50 of PDOX and DOX was 14.9 and 4.9 µM, respectively. Both PDOX and DOX significantly decreased p­ERK1/2, increased ROS generation, reduced mitochondrial membrane potential, caused mitochondrial swelling and arrested the cell cycle at the G2/S phase, and these effects were more pronounced for PDOX than for DOX. PDOX and DOX have different mechanisms of action, particularly the mitochondria­centered intrinsic apoptosis involving reactive oxidative stress and the ERK1/2 signaling pathway.

Primary yolk sac tumor of seminal vesicle: a case report and literature review.

BACKGROUND: Yolk sac tumor (endodermal sinus tumor) is a rare malignant germ cell tumor arising in the testis or ovary. Extragonadal yolk sac tumor is even rarer and has only been described in case reports. Due to the rarity of the tumors, the appropriately optimal treatment remains unclear. We report a case of yolk sac tumor in the seminal vesicle. CASE: A 38-year-old Asian male presented with gross hematuria and hemospermia. Transrectal ultrasound scan showed a solid mass in the left seminal vesicle and the scrotal sonography showed no abnormalities. Bilateral seminal vesicles were resected, and histopathological examination showed a typical pattern of yolk sac tumor (YST). The patient responded poorly to comprehensive treatment of radiotherapy, chemotherapy and surgeries, developed systemic multiple metastases, and died of cachexia one and half years after diagnosis.

Cathepsin B cleavable novel prodrug Ac-Phe-Lys-PABC-ADM enhances efficacy at reduced toxicity in treating gastric cancer peritoneal carcinomatosis: an experimental study.

BACKGROUND: Doxorubicin (Adriamycin) is effective in gastric cancer treatment, but with severe dose-dependent toxicities. A novel prodrug of doxorubicin (Ac-Phe-Lys-PABC-ADM) is designed to deliver free doxorubicin relying on cathepsin B and reduce side effects. The authors examined the antitumor effect and toxicities of Ac-Phe-Lys-PABC-ADM against gastric cancer peritoneal carcinomatosis. METHODS: SGC-7901 gastric cancer cell line was used for the study. The in vitro study investigated the effects of doxorubicin and Ac-Phe-Lys-PABC-ADM on cell growth dynamics and cell cycle. The in vivo study investigated the efficacy and toxicity of Ac-Phe-Lys-PABC-ADM on a nude mice model of peritoneal carcinomatosis, with doxorubicin as positive control. RESULTS: In the in vitro study, Ac-Phe-Lys-PABC-ADM had a lower dose-dependent inhibitory effect on SGC-7901 cells. In the in vivo study of control, doxorubicin, and Ac-Phe-Lys-PABC-ADM groups, the median experimental peritoneal carcinomatosis indexes were 6, 1.5, and 1, respectively (P = .004); the body weights were 24.32 ± 1.40 g, 18.40 ± 2.97 g, and 23.61 ± 0.80 g, respectively (P = .000). Biochemical studies showed that Ac-Phe-Lys-PABC-ADM had significantly lower toxicities on the bone marrow, liver, kidney, and particularly heart. Histopathological studies of the control, doxorubicin, and Ac-Phe-Lys-PABC-ADM groups found significant myocardium toxicities in 3, 7, and 4 animals, respectively. CONCLUSIONS: Ac-Phe-Lys-PABC-ADM could be an effective molecular targeting drug to treat gastric cancer peritoneal carcinomatosis with enhanced efficacy and reduced toxicity.