The Effect of Pretreatment with Chemotherapeutic Drugs on the Susceptibility to Lymphokine Activated CD8+ T Lymphocyte-Mediated Cytotoxicity in CMK Leukemia Cells
Pages 218-225
Bülent Özgönenel, Öner Özdemir, Melike Özgönenel, Ronald Thomas, Steven Buck and Süreyya Savaşan
DOI: http://dx.doi.org/10.6000/1927-7229.2013.02.04.5
Published: 31 October 2013

Abstract: Objectives: Certain tumor cells pretreated with chemotherapeutic drugs become more susceptible to death by apoptosis induced by killer cells of the immune system. We examined the CD8+ cytotoxic T lymphocyte (CTL)-mediated cytotoxicity in myeloid leukemia cell lines pretreated with chemotherapeutic drugs.

Methods: Peripheral blood mononuclear cells were expanded in vitro in the presence of phytohemagglutinin-P, interleukins-2 and -15. CD3+ CD8+ cells representing the CTLs were isolated using magnetic immunoselection and used in immune cytotoxicity experiments against K562 and CMK leukemia cells, pretreated with two different concentrations of cytarabine and etoposide.

Results: In CMK cells pretreated with etoposide at 2 μM and 20 μM concentrations, the mean cell-mediated immune cytotoxicity rose to 21.4 ± 12.9% (p=0.09) and 23.4 ± 12.6% (p=0.046), respectively, when compared to the control value of 6.6 ± 3.8%. In CMK cells pretreated with cytarabine at 1 μM and 10 μM concentrations, the mean immune cytotoxicity rose to 14.3 ± 11.2% and 22.6 ± 15.2%, respectively, compared to the control value of 8.7 ± 6.3%, although these results did not reach statistical significance. However, a similar increase in CTL-mediated immune cytotoxicity was not observed against drug-treated K562 cells.

Conclusion: This study suggests that pretreatment with chemotherapeutic drugs can render CMK leukemia cells more susceptible to immune attack by activated CTLs. Further studies are needed to explore this phenomenon, to establish an immune-enhancing effect of pretreatment with chemotherapy in the treatment of leukemia.

A DNA Vaccine Targeting the Fetal Liver Kinase-1 (Flk-1) can Activate the Special CD8+ T Cell and Inhibit the Metastasis of Orthotopic Lewis Lung Cancer Model
Pages 233-240
Xin Liu, Yan Chen, Zhi Ping Wu, Cong Guo Jin, Xiao Qun Chen, Jia Li, Yong Chun Zhou and Xi Cai Wang
DOI: http://dx.doi.org/10.6000/1927-7229.2013.02.04.6
Published: 31 October 2013

Abstract: Lung cancer is the leading cause of cancer related deaths and need new more effective therapies. In this study, we investigated the anti-tumor effect of recombinant orally DNA vaccine delivered by attenuated S.typhimurium strain SL3261 (aroA mutant) targeting vascular endothelial growth factor receptor (VEGFR-2), also known as fetal liver kinase-1 (Flk-1) in mouse. The cDNA of extracellular domains (ECD) of VEGFR-2 (Flk-1_ECD) was amplified by RT-PCR and cloned into the pcDNA3.1 (+) vector, then transformed to the attenuated S.typhimurium strain to construct the oral DNA vaccine. Then pcDNA3.1-Flk-1_ECD was successfully transfected into COS-7 cells and the recombinant protein was detected by Western blot. The effect of the oral DNA vaccine was analyzed by flow cytometry (FCM) analysis and cytotoxicity assay. For mimic the local and regional growth pattern seen in lung cancer patients, the effect of the oral DNA vaccine on tumor growth and metastasis was analyzed by orthotopic cancer cells challenge in vivo. The results demonstrated that the oral DNA vaccine can overcome peripheral immune tolerance, and generated Flk-1- specific CD8⁺ cytotoxic T cell response. Moreover, this oral DNA vaccine could effectively reduce tumor growth, metastasis and increase the survival. It indicated that the oral VEGFR2 DNA vaccine encoding Flk-1_ECD delivered by salmonella might act a potential strategy for immunotherapy of lung cancers.

Bevacizumab Plus Chemotherapy as First-Line Treatment for Patients with Metastatic Colorectal Cancer: Results from a Spanish Observational Study
Pages 128-134
Pedro Salinas Hernández, Rafael Trujillo Vilchez, Antonio Arriví García-Ramos, Rosana Grande Ladron de Guevara, Angeles Rodríguez Jaraiz, Pedro Gallurt Moreira, Jose Maria Vieitez de Prado, Miguel Ruiz López de Tejada, Antonio Irigoyen Medina, Juan Manuel Campos Cervera, Juan Carlos Cámara Vicario, Uriel Bohn Sarmiento, Pedro López Tendero, Juan Domingo Alonso Lajara, Ana León Carbonero, Marisa García de Paredes, Juan de Alvaro Liaño, Asunción Juarez Marroquí, Luis López Gómez and Diego Soto de Prado Otero
DOI: http://dx.doi.org/10.6000/1927-7229.2013.02.03.1
Published: 31 July 2013

Abstract: Background: This observational study evaluated the efficacy and safety of treatment with bevacizumab plus chemotherapy until disease progression (PD) in Spanish patients with metastatic colorectal cancer (mCRC).

Methods: This multicentre, retrospective, observational analysis included patients receiving bevacizumab plus fluoropyrimidine-based chemotherapy as first-line treatment for mCRC who then developed PD. All patients received treatment in hospital oncology departments and none received bevacizumab as part of a clinical trial. Patients discontinuing treatment with bevacizumab for reasons other than PD were excluded. The primary endpoint was PFS; secondary endpoints were overall response rate (ORR) and safety.

Results: Overall, 165 patients were evaluable for analysis: median age 63.0 years; male/female 62%/38%; ECOG performance status 0/1/2 55%/43%/2%. Median duration of bevacizumab treatment was 8.7 months. ORR was 48.5% (6 complete and 74 partial responses) and disease control rate was 74%. Median progression-free survival (PFS) was 8.4 months (95% CI 7.2–9.6). Patients receiving oxaliplatin- or irinotecan-based regimens had median PFS of 9.2 and 7.7 months, respectively; those receiving treatment not containing either oxaliplatin or irinotecan had a median PFS of 6.1 months. KRAS status did not have a statistically significant effect on PFS (9.5 vs. 7.8 months for KRAS wild-type vs. mutant tumours, respectively; p=0.647) or ORR (44.8% vs. 52.6%, respectively; p=0.391). The most common grade 3/4 adverse events were: diarrhoea (7%), paraesthesia (7%), neutropenia (3%), cutaneous toxicity (2%), and thrombocytopenia (2%).

Conclusions: Treatment with bevacizumab plus standard chemotherapy is an effective and well-tolerated option for patients with mCRC who continue treatment until PD.

Hepatocellular Carcinoma Microvessel Density Quantitation with Image Analysis: Correlation with Prognosis
Pages 135-141
Amr Mohamed, Shelley A. Caltharp, Jason Wang, Cynthia Cohen and Alton B. Farris
DOI: http://dx.doi.org/10.6000/1927-7229.2013.02.03.2
Published: 31 July 2013

Abstract: Hepatocellular carcinoma (HCC) has a progression considered to be dependent on angiogenesis. Intratumoral microvessel density (MVD) has been associated with metastasis and recurrence risk; however, selection bias, counting errors, and lack of standardized assessment criteria have limited the clinical utility of angiogenesis quantitation. Therefore, we analyzed HCC angiogenesis with image cytometry using different methods and determined the correlation to prognosis. Tissue microarrays with 135 HCCs were CD31 and CD34 immunostained and quantitated with the Dako ACIS III Image Cytometer labeling index (LI) and Aperio Scanscope XT and MVD algorithm. LI and MVD were compared to each other and to pathologic features and prognosis (recurrence free survival). Using median cutoffs of microvesselquantitation, survival curve analysis showed a statistically significant difference between CD31 MVD algorithm measurement and prognosis (low MVD mean survival = 56.6 months and high MVD mean = 26.5 months; Log-Rank P = 0.0076). Survival was not significantly related to CD31 LI, CD34 LI or CD34 MVD. By linear regression, a direct correlation was observed between CD31 and CD34 using MVD (r = 0.45, P <0.0001), between CD31 MVD and CD31 LI (r = 0.55, P < 0.0001), and between CD31 LI and CD34 LI (r = 0.51, P < 0.0001). In addition, there was a weak but statistically significant relationship between CD31 MVD and CD34 LI (r = 0.25, P = 0.0050). Together, this data confirms previous studies linking angiogenesis to disease prognosis and suggests the utility of MVD image analysis algorithms.

A Review of the Expression of Genes Involved in Sex Steroid Hormone Metabolism in Prostate Tissue: A Need for Epigenetic Information
Pages 142-150
Jamie Ritchey, Wilfried Karmaus, Tara Sabo-Attwood, Susan E. Steck and Hongmei Zhang
DOI: http://dx.doi.org/10.6000/1927-7229.2013.02.03.3
Published: 31 July 2013

Abstract: There is strong clinical and laboratory evidence indicating that sex steroid hormones are important to the development and progression of prostate cancer, yet results from epidemiologic research conflicts. Examining gene expression in the sex steroid hormone pathway may uncover differences between cancerous and non-cancerous prostate tissues, yet our review using a pathway-oriented approach indicates that there is limited consistency across results, with the exception of GSTP1 found in the estrogen pathway, which was under-expressed in cancerous prostate tissue. This agrees with past studies that reported GSTP1 is methylated in prostate cancer. With new cost-effective technology, we can screen for epigenetic markers, like methylation, which can be applied in epidemiological studies. A clearer understanding of gene expression and epigenetic mechanisms in prostate cancer may contribute to improving prevention, diagnosis, and treatment.