Project description:We generated immune checkpoint blockade resistant cell lines from a prostate tumor driven by Probasin-Cre Pten/P53/Smad4 loxp deletion, through serial implantation and ICB treatment. We then wanted to explore whether gene expression changes associated with resistance to immune checkpoint blockade could be reversed by treating ICB resistant cells with the pan-HDAC inhibitor Vorinostat. We used a microarray to determine gene expression changes caused by Vorinostat treatment in these cells with biological duplicates.
Project description:Transcriptome analysis was conducted on vorinostat resistant HCT116 cells (HCT116-VR) upon knockdown of potential vorinostat resistance candidate genes in the presence and absence of vorinostat. Potential vorinostat resistance candidate genes chosen for this study were GLI1 and PSMD13, which were identified through a genome-wide synthetic lethal RNA interference screen. To understand the transcriptional events underpinning the effect of GLI1 and PSMD13 knockdown (sensitisation to vorinostat-induced apoptosis), cells were first subjected to gene knockdown, then to treatment with vorinsotat or the solvent control. Two timepoints for drug treatment were assessed: a timepoint before induction of apoptosis (4hrs for siGLI1 and 8hrs for siPSMD13) and a timepoint when apoptosis could be detected (8hrs for siGLI1 and 12hrs for siPSMD13).
Project description:Transcriptome analysis was conducted on vorinostat resistant HCT116 cells (HCT116-VR) upon knockdown of potential vorinostat resistance candidate genes in the presence and absence of vorinostat. Potential vorinostat resistance candidate genes chosen for this study were GLI1 and PSMD13, which were identified through a genome-wide synthetic lethal RNA interference screen. To understand the transcriptional events underpinning the effect of GLI1 and PSMD13 knockdown (sensitisation to vorinostat-induced apoptosis), cells were first subjected to gene knockdown, then to treatment with vorinsotat or the solvent control. Two timepoints for drug treatment were assessed: a timepoint before induction of apoptosis (4hrs for siGLI1 and 8hrs for siPSMD13) and a timepoint when apoptosis could be detected (8hrs for siGLI1 and 12hrs for siPSMD13). There are 42 samples in total, from triplicate independent biological experiments of 14 samples each.
Project description:Purpose: In an HIV cure setting, Vorinostat may provide the “shock” capable of flushing HIV out of the persistent reservoir, while antiretroviral therapy is used to prevent new infections. However, this drug may modulate the expression of human endogenous retroviruses (HERVs). This study demonstrates significant modulation of HERVs and suggests that they should be considered as off-target effects of this drug treatment. Methods: Peripheral blood mononuclear cells were collected from 4 healthy donors. Naive CD4 T cells were isolated and utilized to assess HERV dysregulation after treatment with Vorinostat. Cells were collected for study and exposed to a dose of Vorinostat (10uM dose over a 24 hour period). After this, RNA was extracted from cells and their untreated paired counterparts for deep sequencing by Expression Analysis. Sequence reads that passed quality filters were mapped to the HERVd reference database using Bowtie and counted using HTSeq. Any HERV which did not achieve at least 1 count per million mapped and counted reads in at least 4 samples was discarded. Differential expression was performed upon the filtered dataset with edgeR and using TMM normalization. Results: Using an custom built data analysis pipeline, ~100 million reads per sample were mapped to the HERVd reference database and identified 10784 distinct dysregulated elements Bowtie/HTSeq workflow. Differential expression analysis was performed between vorinostat treated and untreated conditions which demonstrated 2102 dysregulated HERV elements with 1007 downregulated and 1095 upregulated (FDR < 0.05) with EdgeR. Results were further subset with a log2FC ± 3 which resulted in 451 upregulated and 363 downregulated HERV elements from 81 and 82 distinct families respectively. HERV elements from the LTR12 family were by far the most dramatically upregulated in family frequency and fold change magnitude. Further confirmation with droplet digital PCR confirmed upregulation of LTR12 elements and demonstrated an exponential dose response curve with HERV expression found at even moderate doses (334nM) of vorinostat treatment. Conclusions: This study represents the first detailed analysis of HERV dysregulation following vorinostat treatment using the untargeted approach of total RNA-Seq. These results demonstrate that vorinostat dysregulates multiple HERV families with a propensity to upregulate members of the LTR12 HERV family. This study also provides a methodology to analyze HERV dysregulation in future treatments with vorinostat or other drugs by providing a mechanism to choose primer and probe sets which will properly represent HERV dysregulation as expression across an HERV is not uniform or continuous. Finally, this work suggests that HERV dysregulation by vorinostat treatment should be considered an off-target effect of this drug and HERV elements, such as LTR12, should be monitored as biomarkers during shock and kill clinical trials with HDAC inhibitors and that trial subjects should be screened to explore further HIV:HERV interactions.
Project description:Diffuse midline gliomas (DMG) are aggressive pediatric tumors of the central nervous system that are highly resistant to treatments and are inevitably fatal. Lysine to methionine substitution of residue 27 on histone H3 (H3-K27M) is a driver mutation in DMGs, reshaping the epigenetic landscape of these cells to promote tumorigenesis. H3-K27M gliomas are characterized by deregulation of histone acetylation and methylation pathways, as well as the oncogenic MYC pathway. In search of effective treatment, we examined the therapeutic potential of dual targeting of histone deacetylases (HDACs) and MYC in these tumors. Treatment of H3-K27M patient-derived cells with Sulfopin, an inhibitor shown to block MYC-driven tumors in vivo, in combination with the HDAC inhibitor Vorinostat, resulted in substantial decrease in cell viability. Moreover, transcriptome and epigenome profiling revealed synergistic effect of this drug combination in downregulation of prominent oncogenic pathways such as mTOR. Finally, in vivo studies of patient-derived orthotopic xenograft models showed significant tumor size reduction in mice treated with the drug combination. These results highlight the combined treatment of Sulfopin and Vorinostat as a promising therapeutic approach for these aggressive tumors.
Project description:Potential vorinostat-resistance candidate genes were identified using RNA interference screening in vorinostat-resistant HCT116 cells (HCT116-VR) using a synthetic lethal approach. In order to understand the mechanisms by which these genes contributed to vorinostat response, transcriptomic analysis was conducted on HCT116-VR cells and those with siRNA-mediated knockdown of each of the vorinostat resistance candidate genes.
Project description:Potential vorinostat-resistance candidate genes were identified using RNA interference screening in vorinostat-resistant HCT116 cells (HCT116-VR) using a synthetic lethal approach. In order to understand the mechanisms by which these genes contributed to vorinostat response, transcriptomic analysis was conducted on HCT116-VR cells and those with siRNA-mediated knockdown of each of the vorinostat resistance candidate genes. There are 45 samples in total, from triplicate independent biological experiments of 15 samples each. The negative control to which all gene knockdowns are compared is the mock transfection control (mock).
Project description:The study objective was to propose molecular mechanisms of action of the histone deacetylase inhibitor vorinostat. In the PRAVO phase 1 study, patients that were scheduled to receive pelvic palliative radiation to 30 Gy in 3-Gy fractions for gastrointestinal carcinoma, were enrolled onto four sequential dose levels of vorinostat, starting at 100 mg daily with dose escalation in increments of 100 mg. Endpoints included treatment safety and tolerability, tumor response, and biological activity of vorinostat. For the purpose of identifying biomarkers of vorinostat action, peripheral blood mononuclear cells, representing normal tissue exposed to vorinostat, were used. The samples were collected, one at baseline and two on-treatment samples. The time points for sample collection were chosen based on our previous data from experimental colorectal carcinoma models exposed to vorinostat, demonstrating that the maximum tumor histone acetylation 2-3 hours after drug exposure was restored to baseline after 24 hours. In PRAVO study patients, tumor histone hyperacetylation was observed 3 hours after vorinostat administration. From the 17 patients enrolled onto the PRAVO study, a full set of three samples was obtained from 14 individuals: one baseline sample collected prior to commencement of vorinostat treatment (T0), and two on-treatment samples collected 2 and 24 hours after the patient had received the preceding daily dose of vorinostat (T2 and T24). Individual vorinostat dose levels were 100 mg (D100), 200 mg (D200), 300 mg (D300), or 400 mg (D400).
Project description:Analysis of gene expression changes after treatment of neuroblastoma cell line SK-N-BE(2)-C afer 24h and 6d treatment with vorinostat to check for changes in expression of genes regulating autophagy