The impact of CVB3 infection on host cell biology

CVB3 myocarditis can lead to dilated cardiomyopath (DCM). DCM is one of the leading causes of the need for heart transplantation, so it is important to understand the life cycle of CVB3 and its interactions with the host cell. Infection causes rapid death of host cardiomyocytes by altering normal cellular homeostasis for the efficient release of progeny virion. In this chapter, we will examine the impact that CVB3 replication has on host cell biology, from events that take place at receptor ligation to progeny virus release. The primary focus will be on the myriad of signalling pathways that are activated at all stages of virus replication and their downstream effects. We will also discuss some of the extracellular effects of infection as well as immune and matrixmetalloprotease activation. Interactions of host cell proteins with the 5' untranslated region (UTR) are required for translation and replication of CVB3. These interactions do not always benefit the virus since the interactions of a 28-kDa host protein with the 5' UTR are thought to be responsible for inhibitory activity against CVB3. Finally, we will discuss how the elucidation of the different stages of replication has provided the opportunity to develop novel strategies for combating CVB3 infection.

Contribution of direct heating, thermal conduction and perfusion during radiofrequency and microwave ablation

Heat based tumor ablation methods such as radiofrequency (RF) and microwave (MW) ablation are increasingly accepted treatment methods for tumors not treatable by traditional surgery. Typically, an interstitial applicator is introduced under imaging guidance into the tumor, and tissue is destroyed by heating to above approximately 50 degrees C, with maximum tissue temperatures over 100 degrees C. Since high thermal gradients occur during the procedure, thermal conduction contributes significantly towards tissue heating. We created finite element method (FEM) computer models of RF and MW applicators, and determined the thermal conduction term, the resistive (for RF) or dielectric (for MW) loss term, and perfusion term. We integrated these terms over the heating period to obtain relative contribution towards tissue temperature rise (in degrees C) as a function of distance from the applicator. We performed simulations without and with perfusion, where perfusion was assumed to stop above 50 degrees C. During the first 6 minutes, direct heating by RF and MW were dominating throughout the tissue. Over the treatment period (12 min for RF, and 6 min for MW), thermal conduction was dominating at distances between than 12 and 19 mm from the RF electrode, while for MW ablation direct heating dominated everywhere. Even though thermal conduction significantly contributes towards tissue heating during ablative therapies, direct heating by RF or MW is dominating throughout most of the tissue volume. Tissue cooling due to perfusion is more significant during RF heating, in part due to the longer treatment times.

Polymorphisms in estrogen receptor beta, interleukin-8, and interleukin-8 receptor associated with clinical outcome in metastatic colorectal cancer (mCRC) patients treated with 5-fluorouracil/oxaliplatin

4130

Background: Many factors contribute to the progression of colorectal cancer and to chemoresistance. Two factors that have recently gained attention are angiogenesis and sex hormones. Interleukin-8 and its receptors play a critical role in angiogenesis, and polymorphisms in these genes have previously been reported to predict clinical outcome and resistance to therapy in a variety of cancer types. In addition, gender and the subsequent varied levels of sex hormones between males and females may also have an impact on colorectal cancer progression. Sex hormones such as estrogen exert their effects on the cell by binding to steroid receptors such as estrogen receptor beta (ER-β). It is known that ER-β is predominantly expressed in the colon, and that differential expression of this gene is predictive of clinical outcome. Therefore, functional polymorphisms within ER-β, IL-8, and the IL-8 receptors may prove to be molecular markers for predicting clinical outcome in colorectal cancer patients. Methods: 173 patients were enrolled in this phase II study. 152 patients were evaluable for genotyping and statistical analysis. There were 74 females and 78 males, and median age was 60 (range 25–87). The dose of oxaliplatin was 130mg/m2 every 3 weeks and 5-FU was 200mg/m2/day CI for 10 weeks followed by 2 weeks rest. Polymorphisms in estrogen receptor beta, IL-8, and CXCR2 (IL-8 receptor) were tested by PCR. Results: Median follow-up was 18.6 months, response rate 19%, median time to tumor progression 4.2 months and median survival 10.3 months. IL-8 T251A polymorphism was predictive of time to tumor progression (p=0.04, log-rank test). ER-β CA repeat polymorphism was predictive of tumor response as well as time to tumor progression (p=0.015, p=0.012, respectively). ER-β A730G SNP was also predictive of time to tumor progression (p=0.03). Polymorphism in CXCR2 was predictive of tumor response (p=0.034). Conclusions: Our results suggest that polymorphisms within IL-8, CXCR2, and ER-β may affect the progression of colorectal cancer and subsequent clinical outcome. These results highlight the importance of angiogenesis and hormone levels in colorectal cancer.

No significant financial relationships to disclose.

Molecular markers associated with response and clinical outcome to cetuximab/bevacizumab/irinotecan (CBI) versus cetuximab/bevacizumab (CB) in irinotecan-refractory colorectal cancer (BOND2)

4113

Background: Phase II (BOND2) trial of Cetuximab/Bevacizumab/Irinotecan (CBI) vs Cetuximab/Bevacizumab (CB) has shown that bevacizumab added to the efficacy of cetuximab and cetuximab/irinotecan in irinotecan-refractory bevacizumab-naïve CRC patients. We tested whether expression levels of genes involved in angiogenesis (VEGF, IL-8), the EGFR pathway (EGFR, COX2) and DNA repair (ERCC1) are associated with clinical outcome. Patients and Methods: This randomized phase II trial enrolled 81 patients. Treatment plan as: Arm A received IRI at the same dose and schedule as last received prior to study, plus Cetuximab 400 mg/m2 loading dose, then weekly at 250 mg/m2, plus Bevacizumab 5 mg/kg given every other week. Arm B received the same as arm A, but without IRI. FFPE samples for 35 out of 81 patients (M:W 24:11, median age 56 (29–80) enrolled in the BOND2 study were tested. Patients received either with CBI (n=18, Arm A) or with CB (n=17, Arm B). FFPE tissues were dissected using laser-captured microdissection and analyzed EGFR, ERCC1, VEGFA, VEGFR2, COX2, Cyclin D1, IL-8, and NRP1 mRNA expression using a quantitative real-time RT-PCR. Gene expression values are expressed as ratios between the target gene and internal reference gene. Results: All eight genes and treatment arm were considered in the CART analysis. The classification tree for response, progression-free survival, and overall survival are evaluated. The expression levels of VEGFR2 and NRP1 classified patients in 3 response groups with response rate range from 61% to 0%. Patients who were classified as responders (Group I; VEGFR2=0.65 and NRP1<2.285) were at a lower risk for progression, compared with patients who were classified as non- responders (Group II; VEGFR2=0.65 and NRP1=2.285 and Group III; VEGFR2<0.65). The expression levels of NRP1 and ERCC1, and EGFR and VEGFR2 were chosen to classify patients into 3 groups with distinct risk of progression-free survival and overall survival, respectively. Conclusion: These data suggest that gene expression levels may be molecular markers of response for patients with mCRC treated with CBI or CB. Prospective studies are needed to validate these preliminary findings.

No significant financial relationships to disclose.

Phase II study of paclitaxel, cisplatin, and 5-FU combination chemotherapy in patients with advanced gastric cancer

15052

Background: Taxane has been used widely in advanced gastric cancer, but toxicities are problematic. To avoid the bone marrow suppression, docetaxel could be replaced paclitaxel to reduce bone marrow suppression and to improve the efficacy, we planned to augmentation of the dose intensity. This phase II study evaluated the efficacy and safety of combination chemotherapy with paclitaxel, cisplatin, and 5-fluorouracil (5-FU) in advanced gastric cancer. Methods: Patients with histologically confirmed gastric adenocarcinoma, ECOG PS = 2, at least one measurable lesion and adequate organ functions were eligible. Paclitaxel (175 mg/m2) and cisplatin (75 mg/m2) were given as a 1-h intravenous infusion on day 1, followed by 5-FU (750 mg/m2) as a 24-h continuous infusion for 5 days. This cycle was repeated every 3 weeks. Results: Forty-five eligible patients (median age 56 years) were treated in this way. Of the 41 patients in whom efficacy was evaluable, an objective response rate (ORR) was seen in 20 (48.8%), a complete response in two, and a partial response in 18 patients. The median time to progression was 6.9 months (95% CI, 5.86–7.94), and the median overall survival was 13.1 months (95% CI, 8.83–17.37). The main hematological toxicity was neutropenia and greater than grade 3 neutropenia was observed in 67 cycles (25%). Febrile neutropenia developed in three patients (7.3%). The major non-hematological toxicities were asthenia and peripheral neuropathy, but grade 3 or 4 toxicity was not seen. Conclusions: The combination chemotherapy with paclitaxel, cisplatin, and 5-FU is a promising regimen, and was well tolerated in patients with advanced gastric cancer.

No significant financial relationships to disclose.

Use of sex-specific genomic profile to predict clinical outcome in metastatic colorectal cancer (mCRC) patients treated with 5- fluorouracil/oxaliplatin

4122

Background: There is increasing evidence that gender plays a significant role in the development and progression of colorectal cancer (CRC). Rates of CRC incidence are higher among males, and it has been shown that hormone replacement therapy in postmenopausal women reduces the risk of developing CRC, indicating a protective effect of female hormones. These findings indicate that physiological differences between the sexes may contribute to differential tumor development and progression. In the current study, we tested the hypothesis whether males and females would have different genomic profiles that would predict clinical outcome in 5-FU/oxal-treated mCRC. Methods: One hundred seventy-three patients were enrolled in this phase II study. One hundred fifty-two patients were evaluable for genotyping and statistical analysis. There were 74 females and 78 males, and median age was 60 (range 25–87). Twenty-four polymorphisms in 12 genes involved in cancer progression were tested by PCR. CART analysis was used to test for association of polymorphisms with overall survival (OS), time to tumor progression (TTP), and tumor response. Separate regression trees were developed for males and females. Results: Median follow-up was 18.6 months, response rate 19%, median time to tumor progression 4.2 months and median survival 10.3 months. CART analysis by gender generated significantly different regression trees for men versus women. For TTP, males carrying polymorphisms in the ER-β and SCN1A genes had improved TTP, while females carrying polymorphisms in the XPD and EGFR genes had improved TTP. For OS, male patients carrying ER-β and MTHFR polymorphisms had improved OS, while female patients carrying polymorphisms in SCN1A and PLA2 had improved OS. It is notable that analysis of males and females in combination produced a different regression tree than when separated by gender. Conclusions: Our results suggest for the first time that genomic profiling to predict clinical outcome of patients with mCRC depends on gender. Taking gender into account when examining the genetic profile of patients may help to more specifically identify those who will benefit from 5-FU/oxal chemotherapy.

No significant financial relationships to disclose.

Targeting the human double minute (HDM)-2 ubiquitin ligase as a strategy against non-Hodgkin’s lymphoma

14016

Background: The ubiquitin-proteasome pathway has been validated as a target for non-Hodgkin lymphoma (NHL) with the recent approval of bortezomib for mantle cell lymphoma (MCL). In addition to anti-tumor activity, however, proteasome inhibitors have pleiotropic effects, including activation of an anti-apoptotic heat shock protein response, and their use clinically is complicated by toxicities such as peripheral neuropathy. By targeting E3 ubiquitin ligases, which are involved in ubiquitination of only a small subset of cellular proteins, it may be possible to achieve more specific anti-tumor effects with a better therapeutic index. One attractive target is HDM-2, which is responsible for ubiquitination of the p53 tumor suppressor. Methods: To evaluate the therapeutic potential of agents targeting HDM-2, we studied the impact of the small molecule MI-63, an inhibitor of the HDM-2-p53 interaction, in both p53 wild-type and -mutant cell line models. Results: Treatment of wild-type p53 MCL, NHL, and acute lymphocytic leukemia (ALL) cell lines with MI-63 induced a dose- and time- dependent inhibition of proliferation, with an IC50 in the 1.0–5.0 μM range. This was associated with G1/S cell cycle arrest , and apoptosis mediated by caspase-3. MI-63 induced accumulation and phopshorylation of p53 and also enhanced MDM-2 levels. Multiple p53 target genes were induced, including p21Cip1 and p53-upregulated modulator of apoptosis (PUMA), resulting in cleavage of poly-ADP-ribose-polymerase (PARP). Cell lines expressing certain p53 mutants were sensitive to the effects of MI-63, resulting in activation of caspases 3, 8, 9 and apoptosis. Cells without p53 expression were resistant to MI-63, but at higher drug concentrations proliferation was still inhibited, indicating a possible impact on HDM-2-mediated but p53-independent cell death pathways. Combinations of MI-63 with other anti-tumor agents showed enhanced anti-proliferative effects that met the criteria for synergistic interactions. Conclusions: Inhibition of the HDM-2-p53 interaction is a promising approach both by itself, and in combination with currently used chemotherapeutics, against lymphoid malignancies, providing a rational for translation of this agent into the clinic.

No significant financial relationships to disclose.

Alemtuzumab plus CHOP as front-line chemotherapy for patients with peripheral T-cell lymphomas

8069

Background: The present study was conducted to evaluate the safety and efficacy of alemtuzumab plus CHOP chemotherapy for patients with peripheral T-cell lymphomas (PTCLs). Methods: Twenty patients with newly diagnosed PTCLs were enrolled. The treatment consisted of classical CHOP plus alemtuzumab (10 mg/m2 i.v on day 1 and 20 mg/m2 i.v on day 2 in the first cycle, then 30 mg/m2 i.v on day 1 in the subsequent cycles) based on 3-week intervals. Results: Thirteen complete responses (65.0%) and 3 partial responses (15.0%) were confirmed, giving an overall response rate of 80.0 %. The estimated event-free survival at 1 year was 43.3%. The most severe hematologic adverse event was neutropenia, which occurred with a grade 4 intensity in 18 patients (90.0%). Plus, febrile neutropenia was observed in 11 patients (55.0%). Five patients (25%) experienced CMV (cytomegalovirus) reactivation, while 3 patients developed CMV diseases, such as pneumonitis or retinitis. There were 2 treatment-related deaths. Conclusions: The alemtuzumab plus CHOP chemotherapy seemed to produce active antitumor activity in terms of the complete response rates in patients with PTCLs. However, since high infectious and hematologic toxicities were observed, careful monitoring and early treatment to prevent treatment-related mortality are needed.

No significant financial relationships to disclose.

Pharmacogenomic analysis of a randomized phase II trial (BOND 2) of cetuximab/bevacizumab/irinotecan (CBI) versus cetuximab/bevacizumab (CB) in irinotecan-refractory colorectal cancer

4128

Background: Phase II CBI VS CB trial has shown that bevacizumab added the efficacy of cetuximab and cetuximab/irinotecan in irinotecan-refractory bevacizumab-naïve CRC patients. We tested the germline polymorphisms involved in angiogenesis pathway(VEGF, IL-8, TGF-β), EGFR pathway (EGFR, COX-2, CyclinD1,E-cadherin,FCGR2A,3A), DNA repair pathway(ERCC1, XRCC1, XPD) and drug metabolism pathway (GSTP1, UGT1A1) to evaluate their association with clinical outcome. Here we expand our gene polymorphisms data involving EGFR pathway (EGF, FCGR2B, Survivin, ADAMS10/17), Angiogenesis pathway (Neuropilin-1, HIF-1, Tissue factor) and irinotecan metabolism pathway(ABCB1,OATPC). Methods: Genomic DNA was extracted from blood samples. 65 out of 81 patients enrolled in the BOND 2 trial were available for molecular correlates study. these 65 patients include 44 men, 21 women, median age 58 years (range 24–86). Patients received either with CBI (n=31) (Arm A) or with CB (n=34) (Arm B). In Arm A, 12 pts (43%) had PR, the median TTP was 7.1 months, and the median survival was 18.0 months. In Arm B, 9 pts (27%) had PR, the median TTP was 4.6 months, and the median survival was 10.3 months. PCR-RFLP based technique was used to determine polymorphisms. Univariate analysis (Fisher’s exact test for response; log-rank test for TTP and OS) was performed to examine associations between polymorphisms and clinical outcome. Results: For Arm B, we found significant associations between HIF-1 polymorphism and tumor response (P=0.017), between HIF-1, FCGR2B polymorphisms and TTP, and between OATPC polymorphism and OS (P values < 0.05). For Arm A, we found a trend in association between EGF polymorphism and tumor response (P=0.08). Conclusions: These data suggest that germline polymorphisms may be potential molecular markers for clinical outcome for patients with mCRC treated with CBI or CB. Prospective studies are needed to confirm these preliminary findings.

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