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1.
Clin Genitourin Cancer ; 22(4): 102116, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38810324

ABSTRACT

PURPOSE: Adherence to active surveillance in patients with stage 1 testicular cancers may be influenced by factors affecting capacity and motivation to attend appointments. The aims of this study were to assess adherence to active surveillance and analyze factors which may impact adherence. PATIENTS AND METHODS: A retrospective cohort study was conducted in patients diagnosed with stage 1 testicular cancer between 2005 and 2020, and managed with active surveillance at 3 institutions in South Western Sydney, Australia. Adherence with active surveillance was followed to 2023 and patients were subsequently classified into 3 groups: "Optimal," "Adequate" or "Loss to follow-up" (LTFU). Factors for adherence were analyzed using multivariable logistic regression. Disease recurrence was analyzed using multivariable Cox regression. RESULTS: In 125 patients, adherence with active surveillance was assessed as "Optimal" in 64 (51%), "Adequate" in 14 (11%), and LTFU in 47 (38%). Multivariable analysis demonstrated that patients had higher odds of being in the "Optimal" or "Adequate" categories if they were from a culturally and linguistically diverse background (OR 4.86, P = .026), nonsmokers (OR 7.63, P = .0002), not employed (OR 4.93, P = .0085), had a partner (OR 2.74, P = .0326), or were diagnosed after June 2016 (OR 5.22, P = .0016). Recurrence occurred in 21 patients (17%). The risk of recurrence increased with the presence of multiple pathological risk factors (HR 5.77, P = .0032), if patients were unemployed (HR 2.57, P = .032), or if they had "Optimal" or "Adequate" adherence (HR 12.74, P = .0136). CONCLUSION: Adherence with active surveillance was poorer in this cohort of stage 1 testicular cancer patients. Patients from culturally and linguistically diverse backgrounds and those who were nonsmokers, unemployed, with a partner, and later date of diagnosis, were more likely to be adherent with active surveillance.


Subject(s)
Neoplasms, Germ Cell and Embryonal , Patient Compliance , Testicular Neoplasms , Humans , Male , Testicular Neoplasms/psychology , Testicular Neoplasms/pathology , Neoplasms, Germ Cell and Embryonal/psychology , Retrospective Studies , Adult , Risk Factors , Patient Compliance/statistics & numerical data , Watchful Waiting/statistics & numerical data , Middle Aged , Neoplasm Recurrence, Local/psychology , Neoplasm Staging , Australia , Young Adult
2.
Acta Physiol (Oxf) ; : e14167, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38779820

ABSTRACT

AIM: To investigate systemic regulators of the cancer-associated cachexia syndrome (CACS) in a pre-clinical model for lung cancer with the goal to identify therapeutic targets for tissue wasting. METHODS: Using the Kras/Lkb1 (KL) mouse model, we found that CACS is associated with white adipose tissue (WAT) dysfunction that directly affects skeletal muscle homeostasis. WAT transcriptomes showed evidence of reduced adipogenesis, and, in agreement, we found low levels of circulating adiponectin. To preserve adipogenesis and restore adiponectin levels, we treated mice with the PPAR-γ agonist, rosiglitazone. RESULTS: Rosiglitazone treatment increased serum adiponectin levels, delayed weight loss, and preserved skeletal muscle and adipose tissue mass, as compared to vehicle-treated mice. The preservation of muscle mass with rosiglitazone was associated with increases in AMPK and AKT activity. Similarly, activation of the adiponectin receptors in muscle cells increased AMPK activity, anabolic signaling, and protein synthesis. CONCLUSION: Our data suggest that PPAR-γ agonists may be a useful adjuvant therapy to preserve tissue mass in lung cancer.

3.
Asia Pac J Clin Oncol ; 20(1): 128-137, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38051140

ABSTRACT

PURPOSE: Survivorship care plans (SCP) are recommended as integral to survivorship care but are not routinely provided in many centers. We explore whether SCP from the Sydney Cancer Survivorship Centre (SCSC) clinic was received by general practitioners (GP) and cancer specialists, and their views on SCP. METHODS: A mixed-method study comprising a quality assurance audit, a questionnaire of GP practices and GP, and semi-structured interviews of cancer specialists who referred patients to the SCSC clinic between 2019-2020. Descriptive statistics were used for quantitative data and content analysis for qualitative data. RESULTS: The audit found 153/190 (80.5%) SCSC attendees had SCP uploaded to hospital medical records. The response rate from GP practices was 41%; among the 55 responding practices, 38 (69%) did not receive the SCP. The response rate from GP was 19%; among the 29 responding GP, 25 (86%) indicated the SCP was worthwhile, especially follow-up plans and multidisciplinary team recommendations. Analysis of 14 cancer specialist interviews identified themes of 1) awareness of SCP; 2) access: SCP difficult to locate; 3) process: access and distribution require improvement; 4) systemic issues; 5) content and layout: more concise and better readability required; 6) value: mainly for GP and survivors; 7) use of SCP: limited; 8) recommendations: improve delivery process, enhance layout/content, more stakeholder input, more tailored information. CONCLUSION: Although response rates from GP were low, those responding perceived SCP to be useful. Cancer specialists believed SCP were more valuable for GP and survivors. Process issues, especially SCP delivery, need to be improved.


Subject(s)
General Practitioners , Neoplasms , Humans , Survivorship , Patient Care Planning , Neoplasms/therapy , Survivors
4.
bioRxiv ; 2023 Aug 02.
Article in English | MEDLINE | ID: mdl-37577571

ABSTRACT

The cancer associated cachexia syndrome (CACS) is a systemic metabolic disorder resulting in loss of body weight due to skeletal muscle and adipose tissues atrophy. CACS is particularly prominent in lung cancer patients, where it contributes to poor quality of life and excess mortality. Using the Kras/Lkb1 (KL) mouse model, we found that CACS is associated with white adipose tissue (WAT) dysfunction that directly affects skeletal muscle homeostasis. WAT transcriptomes showed evidence of reduced adipogenesis, and, in agreement, we found low levels of circulating adiponectin. To preserve adipogenesis and restore adiponectin levels, we treated mice with the PPAR-γ agonist, rosiglitazone. Rosiglitazone treatment increased serum adiponectin levels, delayed weight loss, and preserved skeletal muscle and adipose tissue mass, as compared to vehicle-treated mice. The preservation of muscle mass with rosiglitazone was associated with increases in AMPK and AKT activity. Similarly, activation of the adiponectin receptors in muscle cells increased AMPK activity, anabolic signaling, and protein synthesis. Our data suggest that PPAR-γ agonists may be a useful adjuvant therapy to preserve tissue mass in lung cancer.

5.
Cancer Immunol Res ; 11(5): 558-569, 2023 05 03.
Article in English | MEDLINE | ID: mdl-36820825

ABSTRACT

Patients with BRAF-mutant melanoma show substantial responses to combined BRAF and MEK inhibition, but most relapse within 2 years. A major reservoir for drug resistance is minimal residual disease (MRD), comprised of drug-tolerant tumor cells laying in a dormant state. Towards exploiting potential therapeutic vulnerabilities of MRD, we established a genetically engineered mouse model of BrafV600E-driven melanoma MRD wherein genetic BrafV600E extinction leads to strong but incomplete tumor regression. Transcriptional time-course analysis after BrafV600E extinction revealed that after an initial surge of immune activation, tumors later became immunologically "cold" after MRD establishment. Computational analysis identified candidate T-cell recruiting chemokines as strongly upregulated initially and steeply decreasing as the immune response faded. Therefore, we hypothesized that sustaining chemokine signaling could impair MRD maintenance through increased recruitment of effector T cells. We found that intratumoral administration of recombinant Cxcl9 (rCxcl9), either naked or loaded in microparticles, significantly impaired MRD relapse in BRAF-inhibited tumors, including several complete pathologic responses after microparticle-delivered rCxcl9 combined with BRAF and MEK inhibition. Our experiments constitute proof of concept that chemokine-based microparticle delivery systems are a potential strategy to forestall tumor relapse and thus improve the clinical success of first-line treatment methods.


Subject(s)
Melanoma , Proto-Oncogene Proteins B-raf , Animals , Mice , Cell Line, Tumor , Melanoma/drug therapy , Melanoma/genetics , Melanoma/pathology , Mitogen-Activated Protein Kinase Kinases , Mutation , Neoplasm Recurrence, Local , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Proto-Oncogene Proteins B-raf/genetics
6.
Cancer Discov ; 13(4): 1002-1025, 2023 04 03.
Article in English | MEDLINE | ID: mdl-36715544

ABSTRACT

KRAS is the most frequently mutated oncogene in human lung adenocarcinomas (hLUAD), and activating mutations frequently co-occur with loss-of-function mutations in TP53 or STK11/LKB1. However, mutation of all three genes is rarely observed in hLUAD, even though engineered comutation is highly aggressive in mouse lung adenocarcinoma (mLUAD). Here, we provide a mechanistic explanation for this difference by uncovering an evolutionary divergence in the regulation of triosephosphate isomerase (TPI1). In hLUAD, TPI1 activity is regulated via phosphorylation at Ser21 by the salt inducible kinases (SIK) in an LKB1-dependent manner, modulating flux between the completion of glycolysis and production of glycerol lipids. In mice, Ser21 of TPI1 is a Cys residue that can be oxidized to alter TPI1 activity without a need for SIKs or LKB1. Our findings suggest this metabolic flexibility is critical in rapidly growing cells with KRAS and TP53 mutations, explaining why the loss of LKB1 creates a liability in these tumors. SIGNIFICANCE: Utilizing phosphoproteomics and metabolomics in genetically engineered human cell lines and genetically engineered mouse models (GEMM), we uncover an evolutionary divergence in metabolic regulation within a clinically relevant genotype of human LUAD with therapeutic implications. Our data provide a cautionary example of the limits of GEMMs as tools to study human diseases such as cancers. This article is highlighted in the In This Issue feature, p. 799.


Subject(s)
Adenocarcinoma of Lung , Lung Neoplasms , Triose-Phosphate Isomerase , Animals , Humans , Mice , Adenocarcinoma of Lung/genetics , Adenocarcinoma of Lung/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Mutation , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Triose-Phosphate Isomerase/genetics , Triose-Phosphate Isomerase/metabolism
7.
Nat Commun ; 13(1): 4633, 2022 08 08.
Article in English | MEDLINE | ID: mdl-35941104

ABSTRACT

Cancer cachexia is a common, debilitating condition with limited therapeutic options. Using an established mouse model of lung cancer, we find that cachexia is characterized by reduced food intake, spontaneous activity, and energy expenditure accompanied by muscle metabolic dysfunction and atrophy. We identify Activin A as a purported driver of cachexia and treat with ActRIIB-Fc, a decoy ligand for TGF-ß/activin family members, together with anamorelin (Ana), a ghrelin receptor agonist, to reverse muscle dysfunction and anorexia, respectively. Ana effectively increases food intake but only the combination of drugs increases lean mass, restores spontaneous activity, and improves overall survival. These beneficial effects are limited to female mice and are dependent on ovarian function. In agreement, high expression of Activin A in human lung adenocarcinoma correlates with unfavorable prognosis only in female patients, despite similar expression levels in both sexes. This study suggests that multimodal, sex-specific, therapies are needed to reverse cachexia.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Animals , Anorexia/complications , Appetite , Cachexia/drug therapy , Cachexia/pathology , Carcinoma, Non-Small-Cell Lung/pathology , Female , Humans , Lung Neoplasms/metabolism , Male , Mice
8.
Front Oncol ; 12: 903157, 2022.
Article in English | MEDLINE | ID: mdl-35719965

ABSTRACT

Cachexia is a debilitating comorbidity affecting many lung cancer patients. We have previously found that cachectic mice with lung cancer have reduced serum ketone body levels due to low PPARα activity in the liver. Restoring hepatic PPARα activity with fenofibrate increased circulating ketones and delayed muscle and white adipose tissue wasting. We hypothesized that the loss of circulating ketones plays a pathophysiologic role in cachexia and performed two dietary intervention studies to test this hypothesis. In the first study, male and female mice were randomized to consume either a very low carbohydrate, ketogenic diet (KD) or normal chow (NC) after undergoing tumor induction. The KD successfully restored serum ketone levels and decreased blood glucose in cachectic mice but did not improve body weight maintenance or survival. In fact, there was a trend for the KD to worsen survival in male but not in female mice. In the second study, we compounded a ketone ester supplement into the NC diet (KE) and randomized tumor-bearing mice to KE or NC after tumor induction. We confirmed that KE was able to acutely and chronically increase ketone body abundance in the serum compared to NC. However, the restoration of ketones in the circulation was not able to improve body weight maintenance or survival in male or female mice with lung cancer. Finally, we investigated PPARα activity in the liver of mice fed KE and NC and found that animals fed a ketone ester supplement showed a significant increase in mRNA expression of several PPARα targets. These data negate our initial hypothesis and suggest that restoring ketone body availability in the circulation of mice with lung cancer does not alter cachexia development or improve survival, despite increasing hepatic PPARα activity.

9.
Article in English | MEDLINE | ID: mdl-34750173

ABSTRACT

The regenerative capabilities of the liver represent a paradigm for understanding tissue repair in solid organs. Regeneration after partial hepatectomy in rodent models is well understood, while regeneration in the context of clinically relevant chronic injuries is less studied. Given the growing incidence of fatty liver disease, cirrhosis, and liver cancer, interest in liver regeneration is increasing. Here, we will review the principles, genetics, and cell biology underlying liver regeneration, as well as new approaches being used to study heterogeneity in liver tissue maintenance and repair.

10.
Nature ; 597(7875): 263-267, 2021 09.
Article in English | MEDLINE | ID: mdl-34408323

ABSTRACT

Fructose consumption is linked to the rising incidence of obesity and cancer, which are two of the leading causes of morbidity and mortality globally1,2. Dietary fructose metabolism begins at the epithelium of the small intestine, where fructose is transported by glucose transporter type 5 (GLUT5; encoded by SLC2A5) and phosphorylated by ketohexokinase to form fructose 1-phosphate, which accumulates to high levels in the cell3,4. Although this pathway has been implicated in obesity and tumour promotion, the exact mechanism that drives these pathologies in the intestine remains unclear. Here we show that dietary fructose improves the survival of intestinal cells and increases intestinal villus length in several mouse models. The increase in villus length expands the surface area of the gut and increases nutrient absorption and adiposity in mice that are fed a high-fat diet. In hypoxic intestinal cells, fructose 1-phosphate inhibits the M2 isoform of pyruvate kinase to promote cell survival5-7. Genetic ablation of ketohexokinase or stimulation of pyruvate kinase prevents villus elongation and abolishes the nutrient absorption and tumour growth that are induced by feeding mice with high-fructose corn syrup. The ability of fructose to promote cell survival through an allosteric metabolite thus provides additional insights into the excess adiposity generated by a Western diet, and a compelling explanation for the promotion of tumour growth by high-fructose corn syrup.


Subject(s)
Fructose/pharmacology , High Fructose Corn Syrup/pharmacology , Intestinal Absorption/drug effects , Intestinal Mucosa/cytology , Intestinal Mucosa/drug effects , Nutrients/metabolism , Animals , Cell Survival/drug effects , Enzyme Activation , Female , Fructokinases/metabolism , Fructose/metabolism , High Fructose Corn Syrup/metabolism , Hypoxia/diet therapy , Hypoxia/pathology , Intestinal Mucosa/metabolism , Lipid Metabolism/drug effects , Male , Mice , Pyruvate Kinase/metabolism
11.
BMJ Open ; 11(5): e043215, 2021 05 26.
Article in English | MEDLINE | ID: mdl-34039571

ABSTRACT

OBJECTIVES: To identify available literature on prevalence, severity and contributing factors of scan-associated anxiety ('scanxiety') and interventions to reduce it. DESIGN: Systematic scoping review. DATA SOURCES: Ovid MEDLINE, Ovid EMBASE, Ovid PsycINFO, Ovid Cochrane Central Register of Controlled Trials, Scopus, EBSCO CINAHL and PubMed up to July 2020. STUDY SELECTION: Eligible studies recruited people having cancer-related non-invasive scans (including screening) and contained a quantitative assessment of scanxiety. DATA EXTRACTION: Demographics and scanxiety outcomes were recorded, and data were summarised by descriptive statistics. RESULTS: Of 26 693 citations, 57 studies were included across a range of scan types (mammogram: 26/57, 46%; positron-emission tomography: 14/57, 25%; CT: 14/57, 25%) and designs (observation: 47/57, 82%; intervention: 10/57, 18%). Eighty-one measurement tools were used to quantify prevalence and/or severity of scanxiety, including purpose-designed Likert scales (17/81, 21%); the State Trait Anxiety Inventory (14/81, 17%) and the Hospital Anxiety and Depression Scale (9/81, 11%). Scanxiety prevalence ranged from 0% to 64% (above prespecified thresholds) or from 13% to 83% ('any' anxiety, if no threshold). Mean severity scores appeared low in almost all measures that quantitatively measured scanxiety (54/62, 87%), regardless of whether anxiety thresholds were prespecified. Moderate to severe scanxiety occurred in 4%-28% of people in studies using descriptive measures. Nine of 20 studies assessing scanxiety prescan and postscan reported significant postscan reduction in scanxiety. Lower education, smoking, higher levels of pain, higher perceived risk of cancer and diagnostic scans (vs screening scans) consistently correlated with higher scanxiety severity but not age, gender, ethnicity or marital status. Interventions included relaxation, distraction, education and psychological support. Six of 10 interventions showed a reduction in scanxiety. CONCLUSIONS: Prevalence and severity of scanxiety varied widely likely due to heterogeneous methods of measurement. A uniform approach to evaluating scanxiety will improve understanding of the phenomenon and help guide interventions.


Subject(s)
Depression , Neoplasms , Anxiety/epidemiology , Anxiety/etiology , Anxiety Disorders , Humans
12.
Cancer Metab ; 9(1): 12, 2021 Mar 24.
Article in English | MEDLINE | ID: mdl-33762003

ABSTRACT

BACKGROUND: Fructose is an abundant source of carbon and energy for cells to use for metabolism, but only certain cell types use fructose to proliferate. Tumor cells that acquire the ability to metabolize fructose have a fitness advantage over their neighboring cells, but the proteins that mediate fructose metabolism in this context are unknown. Here, we investigated the determinants of fructose-mediated cell proliferation. METHODS: Live cell imaging and crystal violet assays were used to characterize the ability of several cell lines (RKO, H508, HepG2, Huh7, HEK293T (293T), A172, U118-MG, U87, MCF-7, MDA-MB-468, PC3, DLD1 HCT116, and 22RV1) to proliferate in fructose (i.e., the fructolytic ability). Fructose metabolism gene expression was determined by RT-qPCR and western blot for each cell line. A positive selection approach was used to "train" non-fructolytic PC3 cells to utilize fructose for proliferation. RNA-seq was performed on parental and trained PC3 cells to find key transcripts associated with fructolytic ability. A CRISPR-cas9 plasmid containing KHK-specific sgRNA was transfected in 293T cells to generate KHK-/- cells. Lentiviral transduction was used to overexpress empty vector, KHK, or GLUT5 in cells. Metabolic profiling was done with seahorse metabolic flux analysis as well as LC/MS metabolomics. Cell Titer Glo was used to determine cell sensitivity to 2-deoxyglucose in media containing either fructose or glucose. RESULTS: We found that neither the tissue of origin nor expression level of any single gene related to fructose catabolism determine the fructolytic ability. However, cells cultured chronically in fructose can develop fructolytic ability. SLC2A5, encoding the fructose transporter, GLUT5, was specifically upregulated in these cells. Overexpression of GLUT5 in non-fructolytic cells enabled growth in fructose-containing media across cells of different origins. GLUT5 permitted fructose to flux through glycolysis using hexokinase (HK) and not ketohexokinase (KHK). CONCLUSIONS: We show that GLUT5 is a robust and generalizable driver of fructose-dependent cell proliferation. This indicates that fructose uptake is the limiting factor for fructose-mediated cell proliferation. We further demonstrate that cellular proliferation with fructose is independent of KHK.

13.
Cancer Discov ; 11(6): 1411-1423, 2021 06.
Article in English | MEDLINE | ID: mdl-33495197

ABSTRACT

Lung squamous cell carcinoma (LSCC) is the second most prevalent type of lung cancer. Despite extensive genomic characterization, no targeted therapies are approved for the treatment of LSCC. Distal amplification of the 3q chromosome is the most frequent genomic alteration in LSCC, and there is an urgent need to identify efficacious druggable targets within this amplicon. We identify the protein kinase TNIK as a therapeutic target in LSCC. TNIK is amplified in approximately 50% of LSCC cases. TNIK genetic depletion or pharmacologic inhibition reduces the growth of LSCC cells in vitro and in vivo. In addition, TNIK inhibition showed antitumor activity and increased apoptosis in established LSCC patient-derived xenografts. Mechanistically, we identified the tumor suppressor Merlin/NF2 as a novel TNIK substrate and showed that TNIK and Merlin are required for the activation of focal adhesion kinase. In conclusion, our data identify targeting TNIK as a potential therapeutic strategy in LSCC. SIGNIFICANCE: Targeted therapies have not yet been approved for the treatment of LSCC, due to lack of identification of actionable cancer drivers. We define TNIK catalytic activity as essential for maintaining LSCC viability and validate the antitumor efficacy of TNIK inhibition in preclinical models of LSCC.This article is highlighted in the In This Issue feature, p. 1307.


Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Squamous Cell/drug therapy , Lung Neoplasms/drug therapy , Protein Kinase Inhibitors/therapeutic use , Protein Serine-Threonine Kinases/antagonists & inhibitors , Animals , Antineoplastic Agents/pharmacology , Carcinoma, Squamous Cell/genetics , Cell Line, Tumor/drug effects , Epithelial Cells/drug effects , Gene Expression Regulation, Neoplastic , Humans , Lung Neoplasms/genetics , Mice , Molecular Targeted Therapy , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/genetics
14.
Cancer Discov ; 10(9): 1352-1373, 2020 09.
Article in English | MEDLINE | ID: mdl-32571778

ABSTRACT

A hallmark of metastasis is the adaptation of tumor cells to new environments. Metabolic constraints imposed by the serine and glycine-limited brain environment restrict metastatic tumor growth. How brain metastases overcome these growth-prohibitive conditions is poorly understood. Here, we demonstrate that 3-phosphoglycerate dehydrogenase (PHGDH), which catalyzes the rate-limiting step of glucose-derived serine synthesis, is a major determinant of brain metastasis in multiple human cancer types and preclinical models. Enhanced serine synthesis proved important for nucleotide production and cell proliferation in highly aggressive brain metastatic cells. In vivo, genetic suppression and pharmacologic inhibition of PHGDH attenuated brain metastasis, but not extracranial tumor growth, and improved overall survival in mice. These results reveal that extracellular amino acid availability determines serine synthesis pathway dependence, and suggest that PHGDH inhibitors may be useful in the treatment of brain metastasis. SIGNIFICANCE: Using proteomics, metabolomics, and multiple brain metastasis models, we demonstrate that the nutrient-limited environment of the brain potentiates brain metastasis susceptibility to serine synthesis inhibition. These findings underscore the importance of studying cancer metabolism in physiologically relevant contexts, and provide a rationale for using PHGDH inhibitors to treat brain metastasis.This article is highlighted in the In This Issue feature, p. 1241.


Subject(s)
Antineoplastic Agents/therapeutic use , Brain Neoplasms/drug therapy , Brain/pathology , Phosphoglycerate Dehydrogenase/antagonists & inhibitors , Animals , Antineoplastic Agents/pharmacology , Brain/metabolism , Brain Neoplasms/secondary , Cell Line, Tumor , Datasets as Topic , Drug Resistance, Neoplasm , Female , Gene Knockdown Techniques , Glycine/analysis , Glycine/metabolism , Humans , Metabolomics , Mice , Phosphoglycerate Dehydrogenase/genetics , Phosphoglycerate Dehydrogenase/metabolism , Proteomics , RNA-Seq , Serine/analysis , Serine/metabolism , Tumor Microenvironment/drug effects , Xenograft Model Antitumor Assays
15.
Cancer Discov ; 8(5): 556-567, 2018 05.
Article in English | MEDLINE | ID: mdl-29496665

ABSTRACT

Combined MEK and CDK4/6 inhibition (MEKi + CDK4i) has shown promising clinical outcomes in patients with NRAS-mutant melanoma. Here, we interrogated longitudinal biopsies from a patient who initially responded to MEKi + CDK4i therapy but subsequently developed resistance. Whole-exome sequencing and functional validation identified an acquired PIK3CAE545K mutation as conferring drug resistance. We demonstrate that PIK3CAE545K preexisted in a rare subpopulation that was missed by both clinical and research testing, but was revealed upon multiregion sampling due to PIK3CAE545K being nonuniformly distributed. This resistant population rapidly expanded after the initiation of MEKi + CDK4i therapy and persisted in all successive samples even after immune checkpoint therapy and distant metastasis. Functional studies identified activated S6K1 as both a key marker and specific therapeutic vulnerability downstream of PIK3CAE545K-induced resistance. These results demonstrate that difficult-to-detect preexisting resistance mutations may exist more often than previously appreciated and also posit S6K1 as a common downstream therapeutic nexus for the MAPK, CDK4/6, and PI3K pathways.Significance: We report the first characterization of clinical acquired resistance to MEKi + CDK4i, identifying a rare preexisting PIK3CAE545K subpopulation that expands upon therapy and exhibits drug resistance. We suggest that single-region pretreatment biopsy is insufficient to detect rare, spatially segregated drug-resistant subclones. Inhibition of S6K1 is able to resensitize PIK3CAE545K-expressing NRAS-mutant melanoma cells to MEKi + CDK4i. Cancer Discov; 8(5); 556-67. ©2018 AACR.See related commentary by Sullivan, p. 532See related article by Teh et al., p. 568This article is highlighted in the In This Issue feature, p. 517.


Subject(s)
Class I Phosphatidylinositol 3-Kinases/genetics , Drug Resistance, Neoplasm/genetics , GTP Phosphohydrolases/genetics , Melanoma/genetics , Melanoma/metabolism , Membrane Proteins/genetics , Mutation , Ribosomal Protein S6 Kinases, 70-kDa/metabolism , Signal Transduction , Animals , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers , Cell Line, Tumor , Class I Phosphatidylinositol 3-Kinases/metabolism , Cyclin-Dependent Kinase 4/antagonists & inhibitors , Cyclin-Dependent Kinase 6/antagonists & inhibitors , Female , GTP Phosphohydrolases/metabolism , Humans , Melanoma/diagnosis , Melanoma/drug therapy , Membrane Proteins/metabolism , Mice , Middle Aged , Models, Biological , Phosphorylation , Positron-Emission Tomography , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Signal Transduction/drug effects
17.
Oncotarget ; 7(21): 30453-60, 2016 May 24.
Article in English | MEDLINE | ID: mdl-27028853

ABSTRACT

BRAF inhibitor (BRAFi) therapy is associated with the induction of neoplasia, most commonly cutaneous squamous cell carcinoma (cuSCC). This toxicity is explained in part by "paradoxical ERK activation," or the hyperactivation of ERK signaling by BRAFi in BRAF wild-type cells. However, the rate of cuSCC induction varies widely among BRAFi. To explore this mechanistically, we profiled paradoxical ERK activation by vemurafenib, dabrafenib, encorafenib (LGX818), and PLX8394, demonstrating that vemurafenib induces ERK activation the greatest, while dabrafenib and encorafenib have higher "paradox indices", defined as the pERK activation EC80 divided by the IC80 against A375, corresponding to wider therapeutic windows for achieving tumor inhibition without paradoxical ERK activation. Our results identify differences in the paradox indices of these compounds as a potential mechanism for the differences in cuSCC induction rates and highlight the utility of using ERK activity as a biomarker for maximizing the clinical utility of BRAFi.


Subject(s)
Carcinoma, Squamous Cell/chemically induced , MAP Kinase Signaling System/drug effects , Protein Kinase Inhibitors/adverse effects , Proto-Oncogene Proteins B-raf/antagonists & inhibitors , Skin Neoplasms/chemically induced , Apoptosis/drug effects , Carbamates/adverse effects , Cell Line , Cell Line, Tumor , Enzyme Activation/drug effects , Heterocyclic Compounds, 2-Ring/adverse effects , Humans , Imidazoles/adverse effects , Indoles/adverse effects , Mitogen-Activated Protein Kinase 1/metabolism , Oximes/adverse effects , Sulfonamides/adverse effects , Vemurafenib
18.
J Nanobiotechnology ; 13: 25, 2015 Mar 25.
Article in English | MEDLINE | ID: mdl-25890381

ABSTRACT

BACKGROUND: The poor prognosis of patients with drug resistant ovarian cancer and the lack of targeted therapy have raised the need for alternative treatments. Albendazole (ABZ) is an anti-parasite compound capable of impairing microtubule formation. We hypothesized that ABZ could be repurposed as a potential anti-angiogenic drug due to its potent inhibition of vascular endothelial growth factor (VEGF) in ovarian cancer with ascites. However, the poor aqueous solubility of ABZ limits its potential for cancer therapy. In this study, we have assembled ABZ with bovine serum albumin into nanoparticles with a size range of 7-10 nm (BSA-ABZ) and 200-250 nm (Nab-ABZ). We further examined the anticancer effects of ABZ carrying nanoparticles in ovarian cancer cells, in both in vitro and in vivo models. RESULTS: Drug release studies demonstrated that about 93% of ABZ was released from BSA-ABZ 10 nm in comparison to 83% from Nab-ABZ 200 nm at pH 7.4 in 8 days. In vitro cell proliferation studies showed that the BSA-ABZ 10 nm exhibited the highest killing efficacy of ovarian cancer cells with surprisingly least toxicity to healthy ovarian epithelial cells. Confocal microscopy and fluorescence activated cell sorting analysis (FACS) revealed more efficient internalization of the BSA-ABZ 10 nm by cancer cells. For in vivo studies, we examined the tumor growth, ascites formation and the expression of VEGF and secreted protein acidic and rich in cysteine (SPARC) in tumor samples and only VEGF in plasma samples. The BSA-ABZ 10 nm reduced the tumor burden significantly (p < 0.02) at a much lower drug dose (10 µg/ml) compare to free drug. Both formulations were capable of suppressing the ascites volume significantly (p < 0.05) and reducing the number of ascites cells. The expression of VEGF and SPARC was also reduced, which indicates the underlying therapeutic mechanism of the ABZ. CONCLUSION: Our data suggest that the BSA-ABZ may hold promise for the treatment and control of progression of ovarian cancer with ascites. However further studies are required to examine the efficacy of both the formulations in aggressive models of recurrent ovarian cancer with respect to particle size and dosing parameters.


Subject(s)
Albendazole/administration & dosage , Antineoplastic Agents/administration & dosage , Nanoparticles/administration & dosage , Ovarian Neoplasms/drug therapy , Serum Albumin, Bovine/chemistry , Albendazole/pharmacology , Animals , Antineoplastic Agents/pharmacology , Ascitic Fluid/drug effects , Cell Line/drug effects , Epithelial Cells/drug effects , Female , Humans , Mice, Inbred BALB C , Mice, Nude , Nanoparticles/chemistry , Osteonectin/metabolism , Ovarian Neoplasms/pathology , Ovary/cytology , Particle Size , Serum Albumin, Bovine/administration & dosage , Vascular Endothelial Growth Factor A/blood , Vascular Endothelial Growth Factor A/metabolism , Xenograft Model Antitumor Assays
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