Meclizine hydrochloride is an antihistamine widely used for treatment of vertigo and motion sickness. In HCC it has been used for anti-emetic effects, but it is used here as a CAR (constitutive androstane receptor) inverse agonist. The hypothesis of this study is that Meclizine, CAR inverse agonist, will have beneficial therapeutic effect in patients with hepatocellular carcinoma who are candidates for surgical resection, ablation, TACE, Y90 or systemic therapy by blocking tumorigenesis and inducing apoptosis. The effects of Meclizine will be analyzed by measuring messenger RNA level of CAR target genes CYP2B6, c-Myc and FoxM1, the downstream effectors of CAR, by real time quantitative PCR.
The constitutive androstane receptor (CAR, NR1I3) is a nuclear receptor that plays a central role in hepatic detoxification of potentially toxic compounds, or xenobiotics. Chronic CAR activation by specific agonists induces tumors in wild type mice, and strongly promotes hepatocarcinogenesis in combination with initiating mutagens. Both effects are absent in CAR null mice. These tumorigenic effects are associated with an acute induction of hepatocyte proliferation in mice. Preliminary results using partially humanized mice demonstrate a very similar proliferative effect of CAR activation in human hepatocytes. The transcriptional activity of CAR can be reversed by specific inverse agonists. These ligands are analogous to steroid receptor antagonists, converting the transcriptional activation of the agonist bound receptor into transcriptional repression. These compounds are termed inverse agonists because they do not depend on the presence of agonist ligands to exert their repressive effects. Mouse and human CAR proteins are more divergent than other nuclear receptors, and respond to quite different profiles of agonists and inverse agonists. Preliminary results demonstrate that the specific mouse CAR inverse agonist androstanol blocks proliferation and induces apoptosis in mouse liver tumors. This raises the possibility that targeting CAR may represent a new modality of treatment for hepatocellular cancer (HCC) analogous to estrogen and androgen receptor antagonists in breast and prostate cancers. Meclizine, a widely used antihistamine medication for vertigo and motion sickness, is an inverse agonist ligand of human CAR. Investigators hypothesize that reversing CAR function with meclizine will have a beneficial therapeutic effect in patients with HCC by blocking proliferation and inducing apoptosis. Investigators therefore propose a novel window of opportunity trial in which biopsy proven HCC patients will receive oral meclizine daily for 28 (up to 35) days while awaiting surgical resection, radiofrequency ablation, transarterial chemoembolization, Y90 or systemic therapy. The primary test of treatment outcome will be the predicted decrease in expression of downstream CAR target genes (CYP2B6, MYC and FOXM1) in pre and post treatment tumor specimens. Investigators will also measure the change in tumor proliferation and apoptosis by measuring Ki-67 proliferation index and TUNEL assays (terminal deoxynucleotidyl transferase dUTP Nick-End Labeling assay), serum levels of AFP and GDF 15, and overall tumor response by imaging. HCC is the most rapidly increasing cause of cancer mortality in the United States and medical treatment options are limited. Successful completion of this study may identify a new approach to treatment of HCC.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
13
All subjects will receive 50 mg of meclizine taken orally, twice a day (daily dose 100 mg) for 28 (up to 35) days.
Baylor College of Medicine -McNair Campus
Houston, Texas, United States
Baylor College of Medicine
Houston, Texas, United States
Baylor St. Luke's Medical Center
Houston, Texas, United States
Ben Taub General Hospital
Houston, Texas, United States
Harris Health System- Smith Clinic
Houston, Texas, United States
Change in mRNA levels
Quantitative real time PCR(qPCR) can give change in expression level compared to control Delta CT value. Downstream target genes of CAR (CYP2b6,c-Myc, and FoxM) will be measured by qPCR in the pre and post treatment Hepatocellular cancer tissue specimens. The qPCR machine measures the intensity of fluorescence emitted by the probe at each cycle. The Ct measure is a determined PCR cycle and represents the basic result of a qPCR experience. The Ct is the value where the PCR curve crosses the threshold.
Time frame: day1 and last day of treatment(last day would be one time point between day 28 and day 35 of treatment)
Change in Ki-67 proliferation index
The proliferative index is a measure of the number of cells in a tumor that are dividing (proliferating).
Time frame: day1 and last day of treatment(last day would be one time point between day 28 and day 35 of treatment)
change in apoptosis by TUNEL assay
apoptosis will be measured by TUNEL (terminal deoxynucleotidyl transferase dUTP Nick-End Labeling assay)
Time frame: day1 and last day of treatment(last day would be one time point between day 28 and day 35 of treatment)
Tumor response
Assess tumor response by RECIST criteria
Time frame: day1 and last day of treatment(last day would be one time point between day 28 and day 35 of treatment)
Change in Serum AFP
This will be measured in peripheral blood samples
Time frame: day1 and last day of treatment(last day would be one time point between day 28 and day 35 of treatment)
Change in growth differentiation factor (GDF-15)
This will be measured in peripheral blood samples
Time frame: day1 and last day of treatment(last day would be one time point between day 28 and day 35 of treatment)
A panel of CAR downstream target genes
expression of a panel of CAR downstream target genes
Time frame: day1 and last day of treatment(last day would be one time point between day 28 and day 35 of treatment)
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