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12
result(s) for
"Lockhart, Albert C."
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Long non-coding RNA RAMS11 promotes metastatic colorectal cancer progression
2020
Colorectal cancer (CRC) is the most common gastrointestinal malignancy in the U.S.A. and approximately 50% of patients develop metastatic disease (mCRC). Despite our understanding of long non-coding RNAs (lncRNAs) in primary colon cancer, their role in mCRC and treatment resistance remains poorly characterized. Therefore, through transcriptome sequencing of normal, primary, and distant mCRC tissues we find 148 differentially expressed RNAs Associated with Metastasis (
RAMS
). We prioritize
RAMS11
due to its association with poor disease-free survival and promotion of aggressive phenotypes in vitro and in vivo. A FDA-approved drug high-throughput viability assay shows that elevated
RAMS11
expression increases resistance to topoisomerase inhibitors. Subsequent experiments demonstrate
RAMS11
-dependent recruitment of Chromobox protein 4 (CBX4) transcriptionally activates Topoisomerase II alpha (TOP2α
)
. Overall, recent clinical trials using topoisomerase inhibitors coupled with our findings of
RAMS11-
dependent regulation of TOP2α supports the potential use of
RAMS11
as a biomarker and therapeutic target for mCRC.
The role of long non-coding RNAs (lncRNAs) in metastatic colorectal cancer (mCRC) and treatment resistance is unclear. Here, the authors use transcriptome sequencing of matched normal, primary, and metastatic CRC tissues to discover and validate that lncRNA
RAMS11
promotes metastasis and resistance to topoisomerase inhibitors in mCRC.
Journal Article
Synergistic Effects of Concurrent Blockade of PI3K and MEK Pathways in Pancreatic Cancer Preclinical Models
by
Plambeck-Suess, Stacy
,
Xu, Mai
,
Zhong, Hua
in
1-Phosphatidylinositol 3-kinase
,
Analysis
,
Animals
2013
Patients with pancreatic cancer have dismal prognoses, and novel therapies are urgently needed. Mutations of the KRAS oncogene occur frequently in pancreatic cancer and represent an attractive target. Direct targeting of the predominant KRAS pathways have been challenging and research into therapeutic strategies have been now refocused on pathways downstream of KRAS, phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK [MEK]). We hypothesized that concurrent inhibition of the PI3K and MEK pathways would result in synergistic antitumor activity, as it would circumvent the compensatory feedback loop between the two pathways. We investigated the combined effect of the PI3K inhibitor, GDC0941, and the MEK inhibitor, AZD6244, on cell viability, apoptosis and cell signaling in a panel of pancreatic cancer cell lines. An in vivo analysis was conducted on pancreatic cancer xenografts. While BxPC-3 (KRAS wild type) and MIA PaCa-2 (KRAS mutated) cell lines were sensitive to GDC0941 and AZD6244 as single agents, synergistic inhibition of tumor cell growth and induction of apoptosis were observed in both cell lines when the two drugs were combined. Interestingly, phosphorylation of the cap-dependent translational components, 4E-binding protein (p-4E-BP1) and S6 was found to be closely associated with sensitivity to GDC0941 and AZD6244. In BxPC-3 cell xenografts, survival differences were observed between the control and the AZD6244, GDC0941, and combination groups. Our study provides the rationale for concurrent targeting of the PI3K and MEK pathways, regardless of KRAS status, and suggests that phosphorylation of 4E-BP1and S6 can serve as a predictive biomarker for response to treatment.
Journal Article
Phase I pharmacokinetic study of single agent trametinib in patients with advanced cancer and hepatic dysfunction
2022
Background
Trametinib is an oral MEK 1/2 inhibitor, with a single agent recommended phase 2 dose (RP2D) of 2 mg daily (QD). This study was designed to evaluate RP2D, maximum tolerated dose (MTD), and pharmacokinetic (PK) profile of trametinib in patients with advanced solid tumors who had various degrees of hepatic dysfunction (HD).
Methods
Advanced cancer patients were stratified into 4 HD groups based on Organ Dysfunction Working Group hepatic function stratification criteria: normal (Norm), mild (Mild), moderate (Mod), severe (Sev). Dose escalation was based on “3 + 3” design within each HD group. PK samples were collected at cycle 1 days 15-16.
Results
Forty-six patients were enrolled with 44 evaluable for safety [Norm=17, Mild=7, Mod (1.5 mg)=4, Mod (2 mg)=5, Sev (1 mg)=9, Sev (1.5 mg)=2] and 22 for PK analysis. Treatment related adverse events were consistent with prior trametinib studies. No treatment related deaths occurred. Dose limiting toxicities (DLTs) were evaluable in 15 patients (Mild=6, Mod (1.5 mg)=3, Mod (2 mg)=2, Sev (1 mg)=3 and Sev (1.5 mg)=1). One DLT (grade 3 acneiform rash) was observed in a Sev patient (1.5 mg). Dose interruptions or reductions due to treatment related adverse events occurred in 15 patients (34%) [Norm=9, 53%; Mild=2, 29%; Mod (1.5 mg)=1, 33%; Mod (2 mg)=2, 33%; Sev (1 mg)=1, 11%; Sev (1.5 mg)=1; 50%]. There were no significant differences across HD groups for all PK parameters when trametinib was normalized to 2 mg. However, only limited PK data were available for the Mod (n = 3) and Sev (n = 3) groups compared to Norm (n = 10) and Mild (n = 6) groups. Trametinib is heavily protein bound, with no correlation between serum albumin level and unbound trametinib fraction (p = 0.26).
Conclusions
RP2D for trametinib in Mild HD patients is 2 mg QD. There are insufficient number of evaluable patients due to difficulty of patient accrual to declare RP2D and MTD for Mod and Sev HD groups. DLTs were not observed in the highest dose cohorts that reached three evaluable patients – 1.5 mg QD in Mod group, and 1 mg QD in Sev group.
Trial registration
This study was registered in the ClinicalTrials.gov website (
NCT 02070549
) on February 25, 2014. .
Journal Article
HER kinase inhibition in patients with HER2- and HER3-mutant cancers
2018
Somatic mutations of
ERBB2
and
ERBB3
(which encode HER2 and HER3, respectively) are found in a wide range of cancers. Preclinical modelling suggests that a subset of these mutations lead to constitutive HER2 activation, but most remain biologically uncharacterized. Here we define the biological and therapeutic importance of known oncogenic HER2 and HER3 mutations and variants of unknown biological importance by conducting a multi-histology, genomically selected, ‘basket’ trial using the pan-HER kinase inhibitor neratinib (SUMMIT; clinicaltrials.gov identifier NCT01953926). Efficacy in HER2-mutant cancers varied as a function of both tumour type and mutant allele to a degree not predicted by preclinical models, with the greatest activity seen in breast, cervical and biliary cancers and with tumours that contain kinase domain missense mutations. This study demonstrates how a molecularly driven clinical trial can be used to refine our biological understanding of both characterized and new genomic alterations with potential broad applicability for advancing the paradigm of genome-driven oncology.
In a basket trial design, the efficacy of the pan-HER kinase inhibitor neratinib is tested in patients with 21 different tumour types, and responses are determined by mutation and tissue type, and are restricted to HER2-mutant cancers.
Basket trial of HER inhibition
Mutations in, or overexpression of, HER2 and HER3 (members of the epidermal growth factor receptor (EGFR) family) are found in numerous cancer types. Here, the authors conduct a basket trial—a clinical trial whereby patients are given a targeted therapy based on the presence of a molecular marker rather than on their tumour type—to test the efficacy of neratinib, an irreversible inhibitor of all HER kinases. Neratinib was given to 141 patients with one of 21 different tumour types containing mutations in HER2 and HER3, including breast, lung, bladder and colorectal cancer. The results show that responses are determined by mutation and tissue type, and are restricted to HER2-mutant cancers. Clinical benefit is also conditioned by alterations in downstream signalling pathways. The results highlight the potential of basket trials in molecularly driven oncology.
Journal Article
A phase I study of IMP321 and gemcitabine as the front-line therapy in patients with advanced pancreatic adenocarcinoma
by
Suresh, Rama
,
Mitchem, Jonathan B.
,
Sorscher, Steven
in
Adenocarcinoma - drug therapy
,
Adult
,
Aged
2013
Summary
Purpose
This phase I study was conducted to determine the safety profile and maximum tolerated dose (MTD) of IMP321, a soluble lymphocyte activation gene-3 (LAG-3) Ig fusion protein and MHC Class II agonist, combined with gemcitabine in patients with advanced pancreatic adenocarcinoma.
Patients and methods
Patients with advanced pancreatic adenocarcinoma were treated with gemcitabine (1,000 mg/m
2
)(level 1), gemcitabine (1,000 mg/m
2
) plus IMP 321 at 0.5 mg (level 2) and 2.0 mg (level 3), respectively. Safety, toxicity, and immunological markers at baseline and post treatment were assessed.
Results
A total of 18 patients were enrolled to the study, and 17 were evaluable for toxicity. None of the 6 patients who received 0.5 mg IMP321 experienced IMP321-related adverse events. Of the 5 patients who received IMP321 at the 2 mg dose level, 1 experienced rash, 1 reported hot flashes and 2 had mild pain at the injection sites. No severe adverse events previously attributed to IMP321 were observed. No significant differences were observed when comparing pre- and post-treatment levels of monocytes (CD11b+CD14+), conventional dendritic cells (CD11c+) or T cell subsets (CD4, CD8).
Conclusions
IMP321 in combination with gemcitabine is a well-tolerated regimen. IMP321 did not result in any severe adverse events. No incremental activity observed for the additional IMP 321 to gemcitabine at the dose levels evaluated, likely due to sub-optimal dosing. Immunological markers suggested that higher dose levels of IMP321 are needed for future clinical studies.
Journal Article
Vitamin D deficiency and prognostics among patients with pancreatic adenocarcinoma
by
Wang, Jian
,
Ding, Kevin
,
Thomas, Denise
in
Adenocarcinoma - blood
,
Adenocarcinoma - complications
,
Adenocarcinoma - pathology
2013
Background
The prevalence of vitamin D deficiency among patients with cancer has been previously reported. Because vitamin D is fat soluble, patients with pancreatic adenocarcinoma may have an especially high risk of vitamin D deficiency in association with ongoing and varying degrees of malabsorption. However, little is known about the correlation between vitamin D status and prognosis in these patients.
Methods
We conducted a retrospective review of vitamin D status in patients with pancreatic adenocarcinoma who were treated at Siteman Cancer Center. Patients’ demographic information, clinical staging at the time of vitamin D assessment, vitamin D levels, and survival data were collected. Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D (25[OH]D) level of less than 20 ng/mL, and vitamin D insufficiency was defined as a 25(OH)D level of between 20 ng/mL and 30 ng/mL.
Results
Between December 2007 and June 2011, 178 patients with pancreatic adenocarcinoma had their vitamin D levels checked at the time of initial visit at this center. Of these 178 patients, 87 (49%) had vitamin D deficiency, and 44 (25%) had vitamin D insufficiency. The median 25(OH)D level was significantly lower among nonwhite patients and among patients with stage I and II disease. A 25(OH)D level of less than 20 ng/mL was found to be associated with poor prognosis (p = 0.0019) in patients with stage III and IV disease.
Conclusions
Vitamin D insufficiency and deficiency were prevalent among patients with pancreatic adenocarcinoma. The vitamin D level appears to be prognostic for patients with advanced pancreatic adenocarcinoma, and its effects should be further examined in a prospective study.
Journal Article
Author Correction: HER kinase inhibition in patients with HER2- and HER3-mutant cancers
by
Erinjeri, Joseph P.
,
Quinn, David I.
,
Boni, Valentina
in
Author Correction
,
Humanities and Social Sciences
,
multidisciplinary
2019
The 'Competing interests' statement of this Article has been updated; please see the accompanying Amendment. The original Article has not been corrected online.The 'Competing interests' statement of this Article has been updated; please see the accompanying Amendment. The original Article has not been corrected online.
Journal Article
Synergistic Effects of Concurrent Blockade of PI3K and MEK Pathways in Pancreatic Cancer Preclinical Models: e77243
2013
Patients with pancreatic cancer have dismal prognoses, and novel therapies are urgently needed. Mutations of the KRAS oncogene occur frequently in pancreatic cancer and represent an attractive target. Direct targeting of the predominant KRAS pathways have been challenging and research into therapeutic strategies have been now refocused on pathways downstream of KRAS, phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK [MEK]). We hypothesized that concurrent inhibition of the PI3K and MEK pathways would result in synergistic antitumor activity, as it would circumvent the compensatory feedback loop between the two pathways. We investigated the combined effect of the PI3K inhibitor, GDC0941, and the MEK inhibitor, AZD6244, on cell viability, apoptosis and cell signaling in a panel of pancreatic cancer cell lines. An in vivo analysis was conducted on pancreatic cancer xenografts. While BxPC-3 (KRAS wild type) and MIA PaCa-2 (KRAS mutated) cell lines were sensitive to GDC0941 and AZD6244 as single agents, synergistic inhibition of tumor cell growth and induction of apoptosis were observed in both cell lines when the two drugs were combined. Interestingly, phosphorylation of the cap-dependent translational components, 4E-binding protein (p-4E-BP1) and S6 was found to be closely associated with sensitivity to GDC0941 and AZD6244. In BxPC-3 cell xenografts, survival differences were observed between the control and the AZD6244, GDC0941, and combination groups. Our study provides the rationale for concurrent targeting of the PI3K and MEK pathways, regardless of KRAS status, and suggests that phosphorylation of 4E-BP1and S6 can serve as a predictive biomarker for response to treatment.
Journal Article
Extracellular vesicle sorting of α-Synuclein is regulated by sumoylation
by
Russo, Belisa
,
Ludolph, Albert C.
,
Schwalbe, Martin
in
alpha-Synuclein - genetics
,
alpha-Synuclein - metabolism
,
Animals
2015
Extracellular α-Synuclein has been implicated in interneuronal propagation of disease pathology in Parkinson’s Disease. How α-Synuclein is released into the extracellular space is still unclear. Here, we show that α-Synuclein is present in extracellular vesicles in the central nervous system. We find that sorting of α-Synuclein in extracellular vesicles is regulated by sumoylation and that sumoylation acts as a sorting factor for targeting of both, cytosolic and transmembrane proteins, to extracellular vesicles. We provide evidence that the SUMO-dependent sorting utilizes the endosomal sorting complex required for transport (ESCRT) by interaction with phosphoinositols. Ubiquitination of cargo proteins is so far the only known determinant for ESCRT-dependent sorting into the extracellular vesicle pathway. Our study reveals a function of SUMO protein modification as a Ubiquitin-independent ESCRT sorting signal, regulating the extracellular vesicle release of α-Synuclein. We deciphered in detail the molecular mechanism which directs α-Synuclein into extracellular vesicles which is of highest relevance for the understanding of Parkinson’s disease pathogenesis and progression at the molecular level. We furthermore propose that sumo-dependent sorting constitutes a mechanism with more general implications for cell biology.
Journal Article