Quantitative proteomic analysis of HER2 protein expression in PDAC tumors.

Metastatic pancreatic adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the United States, with a 5-year survival rate of only 11%, necessitating identification of novel treatment paradigms. Tumor tissue specimens from patients with PDAC, breast cancer, and other solid tumor malignancies were collected and tumor cells were enriched using laser microdissection (LMD). Reverse phase protein array (RPPA) analysis was performed on enriched tumor cell lysates to quantify a 32-protein/phosphoprotein biomarker panel comprising known anticancer drug targets and/or cancer-related total and phosphorylated proteins, including HER2Total, HER2Y1248, and HER3Y1289. RPPA analysis revealed significant levels of HER2Total in PDAC patients at abundances comparable to HER2-positive (IHC 3+) and HER2-low (IHC 1+ /2+ , FISH-) breast cancer tissues, for which HER2 screening is routinely performed. These data support a critical unmet need for routine clinical evaluation of HER2 expression in PDAC patients and examination of the utility of HER2-directed antibody-drug conjugates in these patients.

Clinical and social factors associated with excess weight in Hispanic and non-Hispanic White children.

BACKGROUND: Hispanic children are disproportionately affected by obesity, with this disparity starting at a young age, and there is a paucity of data comparing factors associated with excess weight in the first year of life in Hispanic vs. non-Hispanic populations. METHODS: Excess weight was defined as weight-for-length ≥95th percentile. The associations of potential risk factors were compared by ethnicity stratification. RESULTS: Of the 1009 children, 302 (30.0%) were Hispanic and 707 (70.0%) were non-Hispanic White. The rate of excess weight was 30.1% and 13.6% among Hispanic and non-Hispanic White children, respectively. Factors associated with excess weight for non-Hispanic White children were higher than recommended weight gain during pregnancy (odds ratio (OR) 1.8 (1.2-3.1)), higher paternal body mass index (BMI) (OR 1.1 (1.02-1.15)), higher birth weight (OR 1.001 (1.001-1.002)), and lower breast milk feedings at 6 months (OR 0.98 (0.96-0.98)). Factors associated with excess weight for Hispanic children were lower maternal education (OR 2.37 (1.1-4.5)) and lower breast milk feedings at 6 months (OR 0.98 (0.96-0.99)). CONCLUSION: There are differential risk factors associated with excess weight at 12 months between Hispanic and non-Hispanic White children. Identification of differential factors in different ethnicities may allow for more targeted anticipatory guidance reduce obesity in at-risk populations.

EPG5 Variants with Modest Functional Impact Result in an Ameliorated and Primarily Neurological Phenotype in a 3.5-Year-Old Patient with Vici Syndrome.

Congenital disorders of autophagy are multisystem disorders with significant neurological involvement. Ectopic p-granules protein 5 (EPG5)-associated Vici syndrome is a prototypical congenital disorder of autophagy and presents with the cardinal features of agenesis of the corpus callosum, cataracts, cardiomyopathy, immunodeficiency, and oculocutaneous hypopigmentation. The majority of EPG5 variants leading to Vici syndrome are null alleles with only a few missense variants published to date. Here we report a 3.5-year-old male with compound heterozygous EPG5 variants [NM_020964.2: c.772G > T/c.5943-9_5943-5del]. His clinical presentation deviates notably from classic Vici syndrome with a lack of hypopigmentation, cataracts, immunodeficiency, cardiomyopathy, or failure to thrive. Neurological manifestations within the known disease spectrum include early-onset global developmental delay, hypotonia, and postnatal microcephaly. Seizures, hearing loss, or optic nerve atrophy are absent, however. Magnetic resonance imaging demonstrates a thin but fully formed corpus callosum. Based on the ameliorated and primarily neurological phenotype, we hypothesized that the functional impact of the EPG5 variants present would be milder with a higher amount of residual EPG5 expression. Analyses of EPG5 messenger ribonucleic acid (mRNA) in the patient and his parents were performed to examine expression level and splicing; mRNA from a healthy control and a patient with classic Vici syndrome was also included. Aberrant splicing due to the intronic mutation was detected, but no loss of expression. In contrast, we observed a 50% reduction in mRNA expression in classic Vici syndrome patient fibroblasts. These results support a model of disease severity, which correlates to the dosage of EPG5 expression.

A phase 1 study of cetuximab and lapatinib in patients with advanced solid tumor malignancies.

BACKGROUND: Acquired resistance to antiepidermal growth factor receptor (anti-EGFR) therapy may be caused by EGFR-v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2 (ErbB2) heterodimerization and pathway reactivation. In preclinical studies, inhibiting ErbB2 blocked this resistance mechanism and resensitized cells to anti-EGFR therapy. Cetuximab targets EGFR, whereas lapatinib inhibits both EGFR and ErbB2. The objective of this phase 1 trial was to assess the safety, dose-limiting toxicities (DLTs), and maximum tolerated doses (MTDs) of cetuximab and lapatinib in patients with solid tumors. METHODS: Patients received standard weekly cetuximab with escalating lapatinib doses of 750 mg, 1000 mg, or 1250 mg daily in 3-week cycles. DLTs were monitored through the end of cycle 2. Pretreatment and post-treatment tumor biopsies and germline DNA samples were obtained for correlative studies. RESULTS: Twenty-two patients were enrolled, and 18 patients each were evaluable for toxicity and response. Fifty-nine percent of patients had received prior anti-EGFR therapy. Common toxicities included rash and diarrhea. No patient experienced a DLT at the highest dose level, and no grade 4 toxicity was observed. Response included no complete responses, 3 partial responses, 9 patients with stable disease, and 6 patients with disease progression, for an overall response rate of 17% and a clinical benefit rate of 67%. The clinical benefit rate in patients who had previously received anti-EGFR therapy was 70%. The mean treatment duration was 4.7 cycles (range, 1-14 cycles). Decreased expression of EGFR/ErbB2 pathway components after treatment was correlated with response, whereas increased expression in the PI3K, Jak/Stat, and MAPK pathways occurred in nonresponders. CONCLUSIONS: The combination of cetuximab and lapatinib was well tolerated, had the expected toxicities, and exhibited notable clinical activity, including in patients who had received previous anti-EGFR therapy. Further clinical study of this combination is warranted.

RAS Mutations Beyond KRAS Exon 2: A Review and Discussion of Clinical Trial Data.

Opinion statement: The addition of targeted therapy to a 5-FU chemotherapy backbone is now a standard of care in metastatic colorectal cancer. Epidermal growth factor receptor (EGFR) inhibitors have been demonstrated to improve progression-free survival (PFS) and overall survival (OS) in the first line for patients with tumors that do not harbor KRAS exon 2 mutations. Eligibility criteria for most clinical trials involving EGFR inhibitors in recent years have used the absence of KRAS exon 2 mutation as the sole criteria for entry, as this specific mutation has been consistently shown to be predictive of a poor response to EGFR inhibitors. However, expanded analyses of first-line metastatic trials reveal that other RAS mutations, such as other KRAS mutations in exons 3 and 4, along with NRAS mutations, are predictive of poor responses to EGFR inhibitors as well. Testing for a full panel of these RAS mutations should be done prior to initiating treatment with an EGFR inhibitor. Further clinical trials are required to determine the predictive impact of each of these individual mutations. To date, they have been analyzed in the aggregate. The addition of targeted therapy, bevacizumab or an EGFR inhibitor, to a chemotherapy backbone should be considered for all appropriate patients. The relevant clinical trials that evaluated patients without any RAS mutation and compared an EGFR inhibitor to chemotherapy alone show a distinct advantage in overall survival and progression-free survival to the groups that received EGFR inhibition. The largest trial that compared bevacizumab with an EGFR inhibitor in the first line, CALGB/SWOG 80405, did not show a statistically significant difference between the two groups, making the use of bevacizumab, cetuximab, or panitumumab reasonable in the first line.

A phase 1/pharmacokinetic study of sunitinib in combination with highly active antiretroviral therapy in human immunodeficiency virus-positive patients with cancer: AIDS Malignancy Consortium trial AMC 061.

BACKGROUND: The treatment of non-acquired immunodeficiency syndrome-defining cancers may be complicated by drug interactions between highly active antiretroviral therapy (HAART) and chemotherapy. This trial is the first by the AIDS Malignancy Consortium to assess targeted therapies and HAART in human immunodeficiency virus-positive patients (ClinicalTrials.gov identifier: NCT00890747). METHODS: In a modified phase 1 study of sunitinib, patients were stratified into 2 treatment arms based on whether they were receiving therapy with ritonavir, a potent CYP3A4 inhibitor. Patients in treatment arm 1 (non-ritonavir HAART) received standard sunitinib dosing (50 mg/day). Treatment arm 2 (ritonavir-based HAART) used a phase 1, 3 + 3 dose escalation design (from 25 mg/day to 50 mg/day). Cycles were comprised of 4 weeks on treatment followed by a 2-week break (6 weeks total). The pharmacokinetics of sunitinib and its active metabolite (N-desethyl sunitinib) were assessed. RESULTS: Nineteen patients were enrolled and were evaluable. Patients on treatment arm 1 tolerated treatment with no dose-limiting toxicity observed. In treatment arm 2, a dose-limiting toxicity was experienced at a dose of 37.5 mg, and an additional 3 of 5 patients experienced grade 3 neutropenia (toxicity graded as per National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]), an uncommon toxicity of sunitinib. No patient achieved a response, but 10 patients had stable disease, including 8 with prolonged disease stability. Efavirenz, a potent inducer of CYP3A4, resulted in increased exposure of N-desethyl sunitinib, whereas ritonavir caused decreased exposure of the metabolite. Hand-foot syndrome was associated with higher steady-state trough concentrations of sunitinib. CONCLUSIONS: Patients receiving non-ritonavir-based HAART regimens tolerated standard dosing of sunitinib. Patients receiving ritonavir-based therapy who were treated with a dose of 37.5 mg/day experienced higher toxicities. Dose reductions of sunitinib to 37.5 mg may be warranted in patients receiving ritonavir.

Effectiveness of an Electronic Medical Record-Based Recognition Tool for the Identification of Incidental Pulmonary Nodules.

BACKGROUND: Incidental pulmonary nodules (IPNs) are lung nodules detected on imaging studies performed for an unrelated reason. Approximately 1.6 million IPNs are detected in the United States every year. Unfortunately, close to 1.1 million (69%) of these IPNs are not managed with appropriate follow-up care. The goal of this study was to assess the utility of a noncommercial electronic medical record (EMR)-based IPN keyword recognition program in identifying IPNs and the ability of lung navigators to communicate these findings to patients. METHODS: This is a observational, implementation study aimed identify IPNs using an EMR-based protocol and to relay results of findings to patients. The patient population included patients 16 and older undergoing computed tomography (CT) chest, CT chest/abdomen, CT angiogram chest, CT chest/abdomen/pelvis, and chest radiography through the radiology department within a large community tertiary medical campus between June 2019 and August 2020. EPIC EMR were queried using criteria designed to find IPNs. A lung navigator reviewed these cases and sorted them into categories based on their size and risk status. After identification of risk factors, actions were taken to directly communicate results to patients. RESULTS: Seven hundred and fifty-three patients were found to have true IPNs without a history of active malignancy involving the lung. On the basis of radiographic measurements, 60% of the nodules identified were <6 mm, 17% were between 6 and 8 mm, 22% were >8 mm, and 12% were deemed nodular opacities. Lung navigators were able to contact a total of 637 (87%) individuals with IPNs and results were directly communicated. Of the 637 patients identified to have an IPN, a total of 12 (2%) cancers were diagnosed. CONCLUSION: We have here demonstrated that the development of an EMR-based keyword recognition platform for the identification of IPNs is a useful and successful tool for communication of IPN findings to patients using lung navigators.

Safety of Nivolumab Added to Chemoradiation Therapy Platforms for Intermediate and High-Risk Locoregionally Advanced Head and Neck Squamous Cell Carcinoma: RTOG Foundation 3504.

PURPOSE: Programmed death-1 immune checkpoint blockade improves survival of patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC), but the benefits of addition to (chemo)radiation for newly diagnosed patients with HNSCC remain unknown. METHODS AND MATERIALS: We evaluated the safety of nivolumab concomitant with 70 Gy intensity modulated radiation therapy and weekly cisplatin (arm 1), every 3-week cisplatin (arm 2), cetuximab (arm 3), or alone for platinum-ineligible patients (arm 4) in newly diagnosed intermediate- or high-risk locoregionally advanced HNSCC. Patients received nivolumab from 2 weeks prior to radiation therapy until 3 months post-radiation therapy. The primary endpoint was dose-limiting toxicity (DLT). If ≤2 of the first 8 evaluable patients experienced a DLT, an arm was considered safe. Secondary endpoints included toxicity and feasibility of adjuvant nivolumab to 1 year, defined as all 7 additional doses received by ≥4 of the first 8 evaluable patients across arms. RESULTS: Of 39 patients (10 in arms 1, 3, 4 and 9 in arm 2), 72% had T3-4 tumors, 85% had N2-3 nodal disease, and 67% had >10 pack-years of smoking. There were no DLTs in arms 1 and 2, 1 in arm 3 (mucositis), and 2 in arm 4 (lipase elevation and mucositis in 1 and fatigue in another). The most common grade ≥3 nivolumab-related adverse events were lipase increase, mucositis, diarrhea, lymphopenia, hyponatremia, leukopenia, fatigue, and serum amylase increase. Adjuvant nivolumab was feasible as defined in the protocol. CONCLUSIONS: Concomitant nivolumab with the 4 tested regimens was safe for patients with intermediate- and high-risk HNSCC, and subsequent adjuvant nivolumab was feasible as defined (NCT02764593).

The rising challenge of non-AIDS-defining cancers in HIV-infected patients.

Since the advent of HAART, patients with HIV infection have seen a significant improvement in their morbidity, mortality, and life expectancy. The incidence of AIDS-defining illnesses, including AIDS-defining malignancies, has been on the decline. However, deaths due to non-AIDS-defining illnesses have been on the rise. These so-called non-AIDS-defining cancers (NADCs) include cancers of the lung, liver, kidney, anus, head and neck, and skin, as well as Hodgkin's lymphoma. It is poorly understood why this higher rate of NADCs is occurring. The key challenge facing oncologists is how to administer chemotherapy effectively and safely to patients on antiretroviral therapy. The challenge to clinicians caring for HIV-infected patients is to develop and implement effective means to screen, treat, and prevent NADCs in the future. This review presents data on the epidemiology and etiology of NADCs, as well as ongoing research into this evolving aspect of the HIV epidemic.

A phase 1 study of efatutazone, an oral peroxisome proliferator-activated receptor gamma agonist, administered to patients with advanced malignancies.

BACKGROUND: Efatutazone (CS-7017), a novel peroxisome proliferator-activated receptor gamma (PPARγ) agonist, exerts anticancer activity in preclinical models. The authors conducted a phase 1 study to determine the recommended phase 2 dose, safety, tolerability, and pharmacokinetics of efatutazone. METHODS: Patients with advanced solid malignancies and no curative therapeutic options were enrolled to receive a given dose of efatutazone, administered orally (PO) twice daily for 6 weeks, in a 3 + 3 intercohort dose-escalation trial. After the third patient, patients with diabetes mellitus were excluded. Efatutazone dosing continued until disease progression or unacceptable toxicity, with measurement of efatutazone pharmacokinetics and plasma adiponectin levels. RESULTS: Thirty-one patients received efatutazone at doses ranging from 0.10 to 1.15 mg PO twice daily. Dose escalation stopped when maximal impact on PPARγ-related biomarkers had been reached before any protocol-defined maximum-tolerated dose level. On the basis of a population pharmacokinetic/pharmacodynamic analysis, the recommended phase 2 dose was 0.5 mg PO twice daily. A majority of patients experienced peripheral edema (53.3%), often requiring diuretics. Three episodes of dose-limiting toxicities, related to fluid retention, were noted in the 0.10-, 0.25-, and 1.15-mg cohorts. Of 31 treated patients, 27 were evaluable for response. A sustained partial response (PR; 690 days on therapy) was observed in a patient with myxoid liposarcoma. Ten additional patients had stable disease (SD) for ≥60 days. Exposures were approximately dose proportional, and adiponectin levels increased after 4 weeks of treatment at all dose levels. Immunohistochemistry of archived specimens demonstrated that PPARγ and retinoid X receptor expression levels were significantly greater in patients with SD for ≥60 days or PR (P = .0079), suggesting a predictive biomarker. CONCLUSIONS: Efatutazone demonstrates acceptable tolerability with evidence of disease control in patients with advanced malignancies.

Quantitation of unbound sunitinib and its metabolite N-desethyl sunitinib (SU12662) in human plasma by equilibrium dialysis and liquid chromatography-tandem mass spectrometry: application to a pharmacokinetic study.

A rapid, selective, and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of unbound sunitinib and its active metabolite N-desethyl sunitinib in plasma. Plasma and post-dialysis buffer samples were extracted using a liquid-liquid extraction procedure with acetonitrile-n-butylchloride (1:4, v/v). Chromatographic separation was achieved on a Waters X-Terra® MS RP(18) column with a mobile phase consisting of acetonitrile and water (60:40, v/v) containing formic acid (0.1%, v/v) using an isocratic run, at a flow-rate of 0.2 mL/min. Analytes were detected by electrospray tandem mass spectrometry in the selective reaction monitoring mode. Linear calibration curves were generated over the ranges 0.1-100 and 0.02-5 ng/mL for sunitinib and 0.2-200 and 0.04-10 ng/mL for N-desethyl sunitinib in plasma and in phosphate-buffered solution, respectively. The values for both within-day and between-day precision and accuracy were well within the generally accepted criteria for analytical methods. The analytical range was sufficient to determine the unbound and total concentrations of both analytes. The method was applied for measurement unbound concentrations in addition to total concentrations of sunitinib and its metabolite in plasma of a cancer patient receiving 50 mg daily dose.

Remote Home Monitoring of Patients With Cancer During the COVID Pandemic: A Pilot Study.

PURPOSE: The COVID-19 pandemic has posed significant challenges in the care of patients with cancer, including how to manage outpatients who are COVID-positive but do not require hospitalization. We explored the use of a remote patient monitoring (RPM) program to care for such outpatients. METHODS: Consecutive patients who were tested for COVID-19 because of symptom onset but were clinically stable were offered enrollment into a pilot RPM program. Patients were provided equipment for vital sign measurements and a computer tablet to enter results three times per day. The results were monitored centrally by clinical staff. The goal was to closely monitor patients and escalate care as warranted. RESULTS: Between March and June of 2020, 29 patients were approached and 26 were enrolled. The mean age was 57 years old (range, 30-88), 14 were women, and patients remained in the program for an average of 16 days (range, 2-63). Twenty-four patients (83%) were on active anticancer therapy. During that time period, only one patient was admitted to the hospital for worsening respiratory symptoms. The percentage of days during which at least one set of data and all three sets of data were entered was 97.2% and 65.7%, respectively. There was no association between the demographic factors of age, sex, or the reason for being monitored with the level of engagement (P > .05). CONCLUSION: In this pilot study, patients with cancer were readily enrolled in a remote home monitoring program. Monitoring was feasible, and there was a high rate of engagement with the program. The role of RPM should be further tested as the COVID pandemic continues.

Comparison of ATP-binding cassette transporter interactions with the tyrosine kinase inhibitors imatinib, nilotinib, and dasatinib.

Although the development of tyrosine kinase inhibitors (TKIs) to control the unregulated activity of BCR-ABL revolutionized the therapy of chronic myeloid leukemia, resistance to TKIs is a clinical reality. Among the postulated mechanisms of resistance is the overexpression of ATP-binding cassette (ABC) transporters, such as P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2), which mediate reduced intracellular drug accumulation. We compared the interactions of the TKIs imatinib, nilotinib, and dasatinib with ABCB1 and ABCG2 in ex vivo and in vitro systems. The TKIs inhibited rhodamine 123 and Hoechst 33342 efflux mediated by endogenous expression of the transporters in murine and human hematopoietic stem cells with potency order nilotinib >> imatinib >> dasatinib. Studies with ABCB1-, ABCG2-, and ABCC1-transfected human embryonic kidney 293 cells verified that nilotinib was the most potent inhibitor of ABCB1 and ABCG2. Cytotoxicity assays in stably transduced K562-ABCG2 and K562-ABCB1 cells confirmed that the TKIs were also substrates for the two transporters. Like imatinib, both nilotinib and dasatinib decreased ABCG2 surface expression in K562-ABCG2 cells. Finally, we found that all TKIs were able to compete labeling of ABCB1 and ABCG2 by the photo-cross-linkable prazosin analog [(125)I]iodoarylazidoprazosin, suggesting interaction at the prazosin-binding site of both proteins. Our experiments support the hypothesis that all three TKIs are substrates of ABC transporters and that, at higher concentrations, TKIs overcome transporter function. Taken together, the results suggest that therapeutic doses of imatinib and nilotinib may diminish the potential of ABCB1 and ABCG2 to limit oral absorption or confer resistance. Clinical data are required to definitively answer the latter question.

Cetuximab in the treatment of rheumatoid arthritis.

Members of the epidermal growth factor receptor (EGFR) family and their associated ligands are commonly expressed by synovial cells, and may be involved in the synovial hyperplasia seen in rheumatoid arthritis and its disease progression. This family of receptors is also expressed in cancer cells, and EGFR targeted therapy is now a mainstay of anticancer therapy. Cetuximab (Erbitux) is a monoclonal antibody directed against the EGFR extracellular receptor that has received Food and Drug Administration approval for the treatment of colorectal cancer as well as head and neck cancer. We report a case of a 61-year-old woman with an extensive history of rheumatoid arthritis requiring multiple therapies, who experienced a surprising remission of her disease and its symptoms while being treated with cetuximab for her head and neck cancer. The case as well as possible mechanisms of action are discussed. Further clinical investigations are clearly warranted.

Association of Ancestral Genetic Admixture and Excess Weight at Twelve Months of Age.

Background/Objective: Understanding the influence of genetically determined ancestry may give insight into the disparities of obesity seen in different ethnic groups beginning at a very early age. Aim: To investigate the relationship between children's ancestral genetic proportions and excess weight at 12 months of age. Methods: Eight hundred twenty-one 12-month-old children were included in this cross-sectional study. Their genetic admixture was estimated using the ancestry and kinship tool kit by projecting the samples into the 1000 Genomes principal component database. Weight-for-length percentile (WFLP) at 12 months of age was categorized as <95th percentile or ≥95th percentile. Multiple logistic regression analysis was performed to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for the association of admixture proportions, including European (EUR), admixed American (AMR), African (AFR), South Asian (SAS), and East Asian (EAS) populations, with WFLP categories, adjusting for maternal education, birth weight, frequency of breastfeeding, and juice consumption. Results: Eight hundred twenty-one children were included; WFLP <95th percentile = 671 (81.7%) and WFLP ≥95th percentile = 150 (18.3%). Crude ORs showed that the EUR admixture was protective [OR 0.45 (95% CI 0.27-0.74)], whereas AMR [OR 3.85 (95% CI 1.92-7.70)] and AFR [OR 5.70 (95% CI 2.19-14.85)] admixtures were positively associated with excess weight. After adjusting for confounding variables, only the AFR admixture was associated with WFLP ≥95th percentile [OR 7.38 (95% CI 2.31-23.59)]. Conclusions: AFRs remain associated with early excess weight after accounting for confounding variables, suggesting that this ancestral genetic background may contribute to the differences seen in early childhood obesity.

Identification of compounds that correlate with ABCG2 transporter function in the National Cancer Institute Anticancer Drug Screen.

ABCG2 is an ATP-binding cassette transporter that counts multiple anticancer compounds among its substrates and is believed to regulate oral bioavailability as well as serve a protective role in the blood-brain barrier, the maternal-fetal barrier, and hematopoietic stem cells. We sought to determine whether novel compounds that interact with the transporter could be identified through analysis of cytotoxicity profiles recorded in the NCI Anticancer Drug Screen database. A flow cytometric assay was used to measure ABCG2 function in the 60 cell lines and generate a molecular profile for COMPARE analysis. This strategy identified >70 compounds with Pearson correlation coefficients (PCCs) >0.4, where reduced drug sensitivity correlated with ABCG2 expression, as well as >120 compounds with PCCs < -0.4, indicating compounds to which ABCG2 expression conferred greater sensitivity. Despite identification of known single nucleotide polymorphisms in the ABCG2 gene in a number of the cell lines, omission of these lines from the COMPARE analysis did not affect PCCs. Available compounds were subjected to validation studies to confirm interaction with the transporter, including flow cytometry, [(125)I]IAAP binding, and cytotoxicity assays, and interaction was documented in 20 of the 27 compounds studied. Although known substrates of ABCG2 such as mitoxantrone or topotecan were not identified, we characterized three novel substrates-5-hydroxypicolinaldehyde thiosemicarbazone (NSC107392), (E)-N-(1-decylsulfanyl-3-hydroxypropan-2-yl)-3-(6-methyl-2,4-dioxo-1H-pyrimidin-5-yl)prop-2-enamide (NSC265473), and 1,2,3,4,7-pentahydroxy-1,3,4,4a,5,11b-hexahydro[1,3]dioxolo[4,5-j]phenanthridin-6(2H)-one [NSC349156 (pancratistatin)]-and four compounds that inhibited transporter function-2-[methyl(2-pyridin-2-ylethyl)-amino]fluoren-9-one hydroiodide (NSC24048), 5-amino-6-(7-amino-5,8-dihydro-6-methoxy-5,8-dioxo-2-quinolinyl)-4-(2-hydroxy-3,4-dimethoxyphenyl)-3-methyl-2-pyridinecarboxylic acid, methyl ester (NSC45384), (17beta)-2,4-dibromo-estra-1,3,5(10)-triene-3,17-diol (NSC103054), and methyl N-(pyridine-4-carbonylamino)carbamodithioate (NSC636795). In summary, COMPARE analysis of the NCI drug screen database using the ABCG2 functional profile was able to identify novel substrates and transporter-interacting compounds.

Targeted therapies to treat non-AIDS-defining cancers in patients with HIV on HAART therapy: treatment considerations and research outlook.

PURPOSE OF REVIEW: Highly active antiretroviral therapy has led to a dramatic improvement in the prognosis of patients diagnosed with HIV and AIDS. This includes a significant decline in the rates of AIDS-related cancers, including Kaposi's sarcoma and non-Hodgkin's lymphoma. Unfortunately, rates of non-AIDS-defining cancers are on the rise, and now exceed the rates of AIDS-related cancers in patients with HIV. Treating non-AIDS-defining cancers in patients who are on highly active antiretroviral therapy is an open and complicated clinical question. RECENT FINDINGS: Newer targeted therapies are now available to treat cancers which were historically refractory to traditional cytotoxic chemotherapy. Highly active antiretroviral therapy agents are notorious for causing drug-drug interactions. The co-administration of targeted chemotherapies with highly active antiretroviral therapy could well impede the efficacy or increase the toxicity of these targeted therapies. Unfortunately little is known about possible drug-drug interactions because HIV patients are typically excluded from clinical trials. SUMMARY: We highlight what is known about how and why highly active antiretroviral therapy agents can affect drug metabolism. We then present the clinical and pharmacological data for nine recently approved targeted therapies - imatinib, dasatinib, nilotinib, erlotinib, sunitinib, lapatinib, bortezomib, sorafenib, and temsirolimus. We conclude with considerations on how to use these new agents to treat non-AIDS-defining cancers, and discuss a future research agenda to better understand and predict potential highly active antiretroviral therapy-targeted therapy interactions.

The 315-316 deletion determines the BXP-21 antibody epitope but has no effect on the function of wild type ABCG2 or the Q141K variant.

ABCG2 is a half-transporter initially described in multidrug-resistant cancer cells and lately identified as an important factor in the pharmacokinetics of its substrates. Q141K is by far the most intensively studied single nucleotide polymorphism of ABCG2 with potential clinical relevance. Here we used stably transfected HEK cells to study the Q141K polymorphism together with the deletion of amino acids 315-316, which were recently reported to coexist in two cancer cell lines (A549 and SK-OV-3). Functional studies confirmed our previous report that when normalized to surface expression, Q141K has impaired transport of mitoxantrone. This result was extended to include the ABCG2-specific substrate pheophorbide a. While we found no functional consequence of deleting amino acids 315 and 316, we did find that the deletion mutant is no longer recognized by the BXP-21 antibody. We conclude that amino acids 315 and 316 form part of the epitope for the BXP-21 antibody.

Endosomal trafficking defects in patient cells with KIAA1109 biallelic variants.

The uncharacterized gene KIAA1 109 has recently been associated with a congenital neurological malformation disorder that variably presents with arthrogryposis, craniofacial and/or cardiac abnormalities. We have identified two additional patients with compound heterozygous KIAA1109 variants presenting with the same neurological malformations. The mechanism whereby KIAA1109 loss of function causes this spectrum of disorders was the primary focus of our studies. We hypothesized that KIAA1109 function could be conserved relative to the fly gene tweek and examined endocytosis and endosome recycling in patient fibroblasts. Furthermore, we examined the structure of the cytoskeleton and cilia based on functional overlap with endocytosis and several known etiologies for neuronal migration disorders. Utilizing primary dermal fibroblasts from one patient and a healthy donor, we performed immunofluorescence and endocytosis assays to examine the endosomal, cytoskeletal, and ciliary cellular phenotypes. We found notable abnormalities in endosomal trafficking and endosome recycling pathways. We also observed changes in the actin cytoskeleton and cilia structural dynamics. We conclude that the function of KIAA1109 in humans may indeed overlap with the function of the Drosophila ortholog, resulting in perturbations to endosomal trafficking and the actin cytoskeleton. These alterations have ripple effects, altering many pathways that are critical for proper neuronal migration and embryonic development.