Rachel Gonzalez

Aberrant redox regulation in human metastatic melanoma cells compared to normal melanocytes

Melanocytes and melanoma cells contain melanin, a complex polymer that modulates redox changes in these cells. Relative intracellular hydrogen peroxide levels measured by dichlorodihydrofluorescein are similar in the two cell types, but the levels of superoxide anion measured by dihydroethidium were markedly increased in melanoma cells. Chelator-induced oxidative stress is efficiently suppressed by melanocytes without substantial recruitment of the transcription factors NF-kappaB and AP-1 as measured by electrophoretic mobility shift assay and quantitated by densitometry or by a change in frequency of apoptosis as determined by annexin V binding. In contrast, NF-kappaB in melanoma cells is strongly recruited by changes in redox status and exhibits a correlative relationship to intracellular hydrogen peroxide (but not superoxide anion). However, the response of the NF-kappaB pathway to intracellular hydrogen peroxide is anomalous, including downregulation of p65 and IkappaBalpha RNA expression (Northern blot). Additionally, recruitment of AP-1 binding in melanoma cells was directly correlated with intracellular levels of superoxide anion (but not hydrogen peroxide). Neither the degree of NF-kappaB nor AP-1 binding in melanoma cells was related to the frequency of apoptosis. The responsiveness of NF-kappaB and AP-1 recruitment to intracellular levels of hydrogen peroxide and superoxide anion without concomitant control of apoptosis provides a general mechanism by which these cells can escape noxious injury (e.g., chemotherapy). The marked enhancement of apoptosis in melanoma cells by chelators indicates, however, that this alteration can be circumvented and offers a unique therapeutic window to explore.

The Association Between Implementation Strategy Use and the Uptake of Hepatitis C Treatment in a National Sample

BackgroundHepatitis C virus (HCV) is a common and highly morbid illness. New medications that have much higher cure rates have become the new evidence-based practice in the field. Understanding the implementation of these new medications nationally provides an opportunity to advance the understanding of the role of implementation strategies in clinical outcomes on a large scale. The Expert Recommendations for Implementing Change (ERIC) study defined discrete implementation strategies and clustered these strategies into groups. The present evaluation assessed the use of these strategies and clusters in the context of HCV treatment across the US Department of Veterans Affairs (VA), Veterans Health Administration, the largest provider of HCV care nationally.MethodsA 73-item survey was developed and sent to all VA sites treating HCV via electronic survey, to assess whether or not a site used each ERIC-defined implementation strategy related to employing the new HCV medication in 2014. VA national data regarding the number of Veterans starting on the new HCV medications at each site were collected. The associations between treatment starts and number and type of implementation strategies were assessed.ResultsA total of 80 (62%) sites responded. Respondents endorsed an average of 25 ± 14 strategies. The number of treatment starts was positively correlated with the total number of strategies endorsed (r = 0.43, p < 0.001). Quartile of treatment starts was significantly associated with the number of strategies endorsed (p < 0.01), with the top quartile endorsing a median of 33 strategies, compared to 15 strategies in the lowest quartile. There were significant differences in the types of strategies endorsed by sites in the highest and lowest quartiles of treatment starts. Four of the 10 top strategies for sites in the top quartile had significant correlations with treatment starts compared to only 1 of the 10 top strategies in the bottom quartile sites. Overall, only 3 of the top 15 most frequently used strategies were associated with treatment.ConclusionsThese results suggest that sites that used a greater number of implementation strategies were able to deliver more evidence-based treatment in HCV. The current assessment also demonstrates the feasibility of electronic self-reporting to evaluate ERIC strategies on a large scale. These results provide initial evidence for the clinical relevance of the ERIC strategies in a real-world implementation setting on a large scale. This is an initial step in identifying which strategies are associated with the uptake of evidence-based practices in nationwide healthcare systems.

A Phase II Randomized, Controlled Trial of S-Adenosylmethionine in Reducing Serum α-Fetoprotein in Patients with Hepatitis C Cirrhosis and Elevated AFP

In animal models of hepatocellular carcinoma (HCC), deficiency of S-adenosylmethionine (SAMe) increased the risk of HCC whereas administration of SAMe reduced HCC. The aim of this trial was to determine whether oral SAMe administration to patients with hepatitis C cirrhosis would decrease serum α-fetoprotein (AFP) level, a biomarker of HCC risk in hepatitis C. This was a prospective, randomized, placebo-controlled, double-blind trial of SAMe, up to 2.4 g/d, for 24 weeks as compared with placebo among subjects with hepatitis C cirrhosis and a mildly elevated serum AFP. Primary outcome was change in AFP between baseline and week 24. Secondary outcomes included changes in routine tests of liver function and injury, other biomarkers of HCC risk, SAMe metabolites, markers of oxidative stress, and quality of life. One hundred ten subjects were randomized and 87 (44 SAMe and 43 placebo) completed treatment. There was no difference in the change in AFP during 24 weeks among subjects receiving SAMe as compared with placebo. Changes in markers of liver function, liver injury, and hepatitis C viral level were not significantly different between groups. Similarly, SAMe did not change markers of oxidative stress or serum glutathione level. SAMe blood level increased significantly among subjects receiving SAMe. Changes in quality of life did not differ between groups. Overall, this trial did not find that SAMe treatment improved serum AFP in subjects with advanced hepatitis C cirrhosis and a mildly elevated AFP. SAMe did not improve tests of liver function or injury or markers of oxidative stress or antioxidant potential. Cancer Prev Res; 8(9); 864–72. ©2015 AACR.

Phase IIA trial testing erlotinib as an intervention against intraductal pancreatic mucinous neoplasms.

Intraductal papillary mucinous neoplasms (IPMN) are a distinct type of precursor lesions that cause about 5% of pancreatic adenocarcinoma (1, 2). Four-year survival rates of 40% to 75% are reported (3–7). There is currently no chemotherapy specifically approved for treating IPMNs. The number of IPMN cases has significantly increased over the last decade (8). Cancer Prev Res; 4(4); 512–3. ©2011 AACR.

A phase IIa randomized, double-blind trial of erlotinib in inhibiting epidermal growth factor receptor signaling in aberrant crypt foci of the colorectum.

Colorectal cancer progresses through multiple distinct stages that are potentially amenable to chemopreventative intervention. Epidermal growth factor receptor (EGFR) inhibitors are efficacious in advanced tumors including colorectal cancer. There is significant evidence that EGFR also plays important roles in colorectal cancer initiation, and that EGFR inhibitors block tumorigenesis. We performed a double-blind randomized clinical trial to test whether the EGFR inhibitor erlotinib given for up to 30 days had an acceptable safety and efficacy profile to reduce EGFR signaling biomarkers in colorectal aberrant crypt foci (ACF), a subset of which progress to colorectal cancer, and normal rectal tissue. A total of 45 patients were randomized to one of three erlotinib doses (25, 50, and 100 mg) with randomization stratified by nonsteroidal anti-inflammatory drug (NSAID) use. There were no unanticipated adverse events with erlotinib therapy. Erlotinib was detected in both normal rectal mucosa and ACFs. Colorectal ACF phosphorylated ERK (pERK), phosphorylated EGFR (pEGFR), and total EGFR signaling changes from baseline were modest and there was no dose response. Overall, this trial did not meet is primary efficacy endpoint. Colorectal EGFR signaling inhibition by erlotinib is therefore likely insufficient to merit further studies without additional prescreening stratification or potentially longer duration of use. Cancer Prev Res; 8(3); 222–30. ©2015 AACR.

Hepatitis C Care in the Department of Veterans Affairs: Building a Foundation for Success

The Department of Veterans Affairs (VA) has made significant progress in treating hepatitis C virus, experiencing more than a 75% reduction in veterans remaining to be treated since the availability of oral direct-acting antivirals. Hepatitis C Innovation Teams use lean process improvement and system redesign, resulting in practice models that address gaps in care. The key to success is creative improvements in veteran access to providers, including expanded use of nonphysician providers, video telehealth, and electronic technologies. Population health management tools monitor and identify trends in care, helping the VA tailor care and address barriers.

Abstract 1706: Evaluation of LGR5 protein expression in colon cancer stem cells

Cancer stem cells are a subpopulation of cancer cells responsible for cancer initiation, development and metastasis. A number of studies demonstrated that Leucine-rich repeat containing G-protein-coupled receptor 5 (LGR5) can drive cancer development through triggering canonical Wnt signaling and its downstream gene expression. LGR5 is an important biomarker specifically expressed on colon cancer stem cells. In this study, we have successfully developed an LGR5 antibody with high specificity to detect endogenous LGR5 expression in different immunoassay application. By screening multiple anti-LGR5 hybridoma clones, antibody generated by clone UMAB212 was proven to be highly specific on our high density protein microarray chip assay. Here our experimental data demonstrated that clone UMAB212 recognizes not only human LGR5 protein but also mouse LGR5 protein in both western blot and flow cytometry applications. No cross-reactivity was observed with the other two LGR family members, LGR4 and LGR6. Furthermore, this antibody also works great on immunohistochemistry application on FFPE tissue blocks. In summary, UMAB212 is great tool for us to study LGR5 protein in different immunoassay setting and it could also be a potential cancer diagnostic reagent. Citation Format: Wei Fu, Rachel Gonzalez, Kehu Yuan, Caiwei Chen, Haitao Wei, Hsiangmin Lu, Qi Ren, Evelin Logis, Sean Kelly, Wei-Wu He, Donghui Ma. Evaluation of LGR5 protein expression in colon cancer stem cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1706.

Abstract 415: A new, highly sensitive ALK antibody improves the screening of rearranged-ALK by IHC

All non-small cell lung cancer (NSCLC) patients are recommended to be screened for anaplastic lymphoma kinase (ALK)-rearrangement despite its low occurrence ( Citation Format: Hsiangmin Lu, Rachel Gonzalez, Yi Shen, Mu-lan Jin, Yipan Wu, Yungang Zhang, Kehu Yuan, Boyang Chu, Lili Qi, Huibo Liu, Chenlin Wang, Guangli Wang, Youmin Shu, Julie McDowell, Donghui Ma, Wei-wu He, Jian Chen, Ray Lin. A new, highly sensitive ALK antibody improves the screening of rearranged-ALK by IHC. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 415.

Abstract 3247: SAMe versus placebo for the reduction of serum AFP in patients with hepatitis C cirrhosis and moderately elevated AFP: A randomized, placebo-controlled, double-blind phase II trial

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Background: Hepatocellular carcinoma (HCC) is a common complication of hepatitis C virus related cirrhosis (HCV-C). Alpha-fetoprotein (AFP) has been proposed as a biomarker of HCC risk. S-adenosylmethionine (SAMe) is a food supplement that has an excellent safety profile. The use of SAMe as a chemopreventive is based on abnormalities in methionine cycle (with decreased SAMe levels) in patients with cirrhosis, increased risk of HCC in experimental animals deprived of SAMe, and the prevention of liver cancer by SAMe administration in animal models of chemically-induced HCC. Methods: This was a prospective, randomized, placebo-controlled, double-blind phase IIb trial to determine if SAMe (up to 2.4 grams/day) for 24 weeks reduced serum AFP levels in patients with HCV-C. Inclusion criteria: lab evidence of HCV-C (platelet count 15), or history of, or mass suspicious for HCC. Primary outcome was decline in AFP between week 0 and 24. Secondary outcomes: change in other HCC-related markers (des-gamma carboxyprothrombin, AFP-L3), blood tests for HCV RNA, SAMe metabolites, serum markers of oxidative stress, and quality of life. Results: A total of 110 patients were enrolled and 87 completed study. After the 24-week treatment, AFP declined among patients receiving SAMe (-1.9 ng/mL) and increased among patients receiving placebo (+5.9 ng/mL; p=0.16). Neither des-gamma carboxyprothrombin (DCP) nor AFP-L3 changed significantly with SAMe treatment. There were no significant differences in serum HCV RNA between groups. Blood levels of SAMe and S-adenosylhomocysteine (SAH) increased 3-5 fold among patients receiving SAMe and were unchanged in placebo group (p<0.01). Serum glutathione and methionine did not change significantly. Several components of quality of life improved among patients receiving SAMe. There were 5 serious adverse events in the placebo group and 7 in the SAMe group; none were attributable to SAMe. Conclusions: SAMe administration for 24 weeks in patients with HCV-C and elevated AFP did not decrease AFP significantly nor alter liver function. SAMe significantly increased serum SAMe and SAH levels, but did not alter serum glutathione level or serum markers of oxidative stress. Citation Format: Timothy Morgan, Frank L. Meyskens, John Hoefs, Ke-Qin Hu, Tarek Hassanein, Thomas D. Boyer, Neville R. Pimstone, Kathy Osann, Rachel Gonzalez, L M. Rodriguez. SAMe versus placebo for the reduction of serum AFP in patients with hepatitis C cirrhosis and moderately elevated AFP: A randomized, placebo-controlled, double-blind phase II trial. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3247. doi:10.1158/1538-7445.AM2014-3247