Evidence for dispersing 1D Majorana channels in an iron-based superconductor.

The possible realization of Majorana fermions as quasiparticle excitations in condensed-matter physics has created much excitement. Most studies have focused on Majorana bound states; however, propagating Majorana states with linear dispersion have also been predicted. Here, we report scanning tunneling spectroscopic measurements of crystalline domain walls (DWs) in FeSe0.45Te0.55 We located DWs across which the lattice structure shifts by half a unit cell. These DWs have a finite, flat density of states inside the superconducting gap, which is a hallmark of linearly dispersing modes in one dimension. This signature is absent in DWs in the related superconductor, FeSe, which is not in the topological phase. Our combined data are consistent with the observation of dispersing Majorana states at a π-phase shift DW in a proximitized topological material.

Prognostic biomarkers in patients with human immunodeficiency virus-positive disease with head and neck squamous cell carcinoma.

BACKGROUND: We examined the prognostic value of a panel of biomarkers in patients with squamous cell carcinoma of the head and neck (SCCHN) who were human immunodeficiency virus (HIV) positive (HIV-positive head and neck cancer) and HIV negative (HIV-negative head and neck cancer). METHODS: Tissue microarrays (TMAs) were constructed using tumors from 41 disease site-matched and age-matched HIV-positive head and neck cancer cases and 44 HIV-negative head and neck cancer controls. Expression of tumor biomarkers was assessed by immunohistochemistry (IHC) and correlations examined with clinical variables. RESULTS: Expression levels of the studied oncogenic and inflammatory tumor biomarkers were not differentially regulated by HIV status. Among patients with HIV-positive head and neck cancer, laryngeal disease site (P = .003) and Clavien-Dindo classification IV (CD4) counts <200 cells/µL (P = .01) were associated with poor prognosis. Multivariate analysis showed that p16 positivity was associated with improved overall survival (OS; P < .001) whereas increased expression of transforming growth factor-beta (TGF-ß) was associated with poor clinical outcome (P = .001). CONCLUSION: Disease site has significant effect on the expression of biomarkers. Expression of tumor TGF-ß could be a valuable addition to the conventional risk stratification equation for improving head and neck cancer disease management strategies.

Integration of high-risk human papillomavirus into cellular cancer-related genes in head and neck cancer cell lines.

BACKGROUND: Human papillomavirus (HPV)-positive oropharyngeal cancer is generally associated with excellent response to therapy, but some HPV-positive tumors progress despite aggressive therapy. The purpose of this study was to evaluate viral oncogene expression and viral integration sites in HPV16- and HPV18-positive squamous cell carcinoma lines. METHODS: E6/E7 alternate transcripts were assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). Detection of integrated papillomavirus sequences (DIPS-PCR) and sequencing identified viral insertion sites and affected host genes. Cellular gene expression was assessed across viral integration sites. RESULTS: All HPV-positive cell lines expressed alternate HPVE6/E7 splicing indicative of active viral oncogenesis. HPV integration occurred within cancer-related genes TP63, DCC, JAK1, TERT, ATR, ETV6, PGR, PTPRN2, and TMEM237 in 8 head and neck squamous cell carcinoma (HNSCC) lines but UM-SCC-105 and UM-GCC-1 had only intergenic integration. CONCLUSION: HPV integration into cancer-related genes occurred in 7 of 9 HPV-positive cell lines and of these 6 were from tumors that progressed. HPV integration into cancer-related genes may be a secondary carcinogenic driver in HPV-driven tumors. © 2017 Wiley Periodicals, Inc. Head Neck 39: 840-852, 2017.

In vivo Wnt pathway inhibition of human squamous cell carcinoma growth and metastasis in the chick chorioallantoic model.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer with poor overall survival. New therapeutic strategies that target specific molecular lesions driving advanced disease are needed. Herein we demonstrate the utility of the chicken chorioallantoic membrane (CAM) assay for in vivo human HNSCC tumor growth and metastasis and the tumor suppressive effects of a new chemotherapeutic agent. METHODS: We tested anti-metastatic effects of a WNT pathway inhibitor, WNT974 (also known as LGK974), which targets porcupine (PORCN) the palmityl-transferase that is essential for secretion of Wnt proteins. CAM assays were performed with 8 HNSCC cell lines: UM-SCC-1, UM-SCC-10A, UM-SCC-10B, UM-SCC-11A, UM-SCC-14A UM-SCC-17A, UM-SCC-17B, UM-SCC-25, and UM-SCC-34. RESULTS: UM-SCC-1 (University of Michigan Squamous Cell Carcinoma cell line) CAM xenografts contain CD44+ and ALDH+ cancer stem cell (CSC) proportions similar to UM-SCC-1 mouse xenografts supporting the applicability of the CAM assay for study of CSCs. Inhibition of WNT signaling by the PORCN inhibitor WNT974 reduced metastatic spread of UM-SCC cells, especially in UM-SCCs with Notch1 deficiency. CONCLUSIONS: Our data demonstrate decreased tumor growth and metastases in tumors from cell lines that showed in vitro responses to WNT974, providing evidence that this agent may have a role in future HNSCC therapy.

Novel method of cell line establishment utilizing fluorescence-activated cell sorting resulting in 6 new head and neck squamous cell carcinoma lines.

BACKGROUND: The purpose of this study was to present the establishment of new cell lines, which is important to cancer research. METHODS: Six new head and neck squamous cell carcinoma cell lines were established using a novel fluorescence-activated cell sorting (FACS) method in order to overcome the barrier of fibroblast overgrowth and the susceptibility of primary tumors to fail in vitro. RESULTS: Antibodies chosen for specific targeting of epithelial cells and fibroblasts successfully separated cells for line establishment in 6 of 12 attempts, providing an alternative method of establishing head and neck squamous cell carcinoma cell lines. Each attempt at cell line establishment resulted in an epithelial carcinoma population, which was genotyped and catalogued as a unique cell line, and a corresponding fibroblast population. CONCLUSION: The selection of antibody markers could be optimized to aid in the establishment of any cancer cell line derived from any tumor tissue; this method is not limited to head and neck cancer. © 2015 Wiley Periodicals, Inc. Head Neck 38: E459-E467, 2016.

A Phase I Study of the SMAC-Mimetic Birinapant in Adults with Refractory Solid Tumors or Lymphoma.

The inhibitor of apoptosis (IAP) family of antiapoptotic proteins has been identified as a target for small molecule inhibitors in cancer. Second mitochondrial-derived activator of caspases (SMAC) efficiently and naturally antagonizes IAPs, and preclinical studies have determined that SMAC mimetics have potent anticancer properties. Here, we report a first-in-human trial designed to determine the maximum tolerated dose (MTD), safety, and pharmacokinetics/pharmacodynamics (PK/PD) of birinapant, a novel SMAC mimetic. Patients with advanced solid tumors or lymphoma were enrolled in a 3+3 dose escalation design with birinapant administered intravenously from 0.18 to 63 mg/m(2) once weekly every 3 of 4 weeks. Fifty patients were enrolled to 12 dose cohorts. Birinapant 47 mg/m(2) was determined to be the MTD. At 63 mg/m(2), dose-limiting toxicities included headache, nausea, and vomiting. Two cases of Bell's palsy (grade 2) also occurred at 63 mg/m(2). Birinapant had a plasma half-life of 30 to 35 hours and accumulated in tumor tissue. Birinapant suppressed cIAP1 and increased apoptosis in peripheral blood mononuclear cells and tumor tissue. Prolonged stable disease was observed in 3 patients: non-small cell lung cancer (5 months), colorectal cancer (5 months), and liposarcoma (9 months). Two patients with colorectal cancer had radiographic evidence of tumor shrinkage. In conclusion, birinapant was well tolerated with an MTD of 47 mg/m(2) and exhibited favorable PK and PD properties. Several patients demonstrated stable disease and evidence of antitumor activity. These results support the ongoing clinical trials of birinapant in patients with cancer.

UM-SCC-103: a unique tongue cancer cell line that recapitulates the tumorigenic stem cell population of the primary tumor.

OBJECTIVE: A new head and neck cancer cell line was developed from a highly aggressive HNSCC of the oral cavity diagnosed in a 26-year-old pregnant woman. METHODS: Cells from the primary tumor were passaged in culture and genotyped as a unique cell line. The resultant cell line was assessed for its ability to replicate the primary tumor. RESULTS: The primary tumor and cell line contained 19.03% and 19.62% CD44(high) cells, respectively. CD44(high) cancer stem cells from UM-SCC-103 formed tumors after flank injections in mice that reconstituted the heterogeneity of the primary tumor. CD44 staining and histology in the primary tumor and tumors grown in vivo from the cell line were similar. CD44(high) cells from the primary tumor resulted in lung colony formation in 2 out of 2 tail vein injections in mice, whereas CD44(low) cells did not. Similarly, CD44(high) cells from UM-SCC-103 formed lung tumors in 2 out of 4 mice, whereas CD44(low) cells did not. CONCLUSION: The similarity in marker expression and tumorigenic behavior between the primary tumor and the resulting cell line strongly suggests that the cell line resembles the primary tumor that it was derived from and provides an important new research tool for the study of head and neck carcinomas in young patients.

Birinapant, a smac-mimetic with improved tolerability for the treatment of solid tumors and hematological malignancies.

Birinapant (1) is a second-generation bivalent antagonist of IAP proteins that is currently undergoing clinical development for the treatment of cancer. Using a range of assays that evaluated cIAP1 stability and oligomeric state, we demonstrated that 1 stabilized the cIAP1-BUCR (BIR3-UBA-CARD-RING) dimer and promoted autoubiquitylation of cIAP1 in vitro. Smac-mimetic 1-induced loss of cIAPs correlated with inhibition of TNF-mediated NF-κB activation, caspase activation, and tumor cell killing. Many first-generation Smac-mimetics such as compound A (2) were poorly tolerated. Notably, animals that lack functional cIAP1, cIAP2, and XIAP are not viable, and 2 mimicked features of triple IAP knockout cells in vitro. The improved tolerability of 1 was associated with (i) decreased potency against cIAP2 and affinity for XIAP BIR3 and (ii) decreased ability to inhibit XIAP-dependent signaling pathways. The P2' position of 1 was critical to this differential activity, and this improved tolerability has allowed 1 to proceed into clinical studies.

Birinapant (TL32711), a bivalent SMAC mimetic, targets TRAF2-associated cIAPs, abrogates TNF-induced NF-κB activation, and is active in patient-derived xenograft models.

The acquisition of apoptosis resistance is a fundamental event in cancer development. Among the mechanisms used by cancer cells to evade apoptosis is the dysregulation of inhibitor of apoptosis (IAP) proteins. The activity of the IAPs is regulated by endogenous IAP antagonists such as SMAC (also termed DIABLO). Antagonism of IAP proteins by SMAC occurs via binding of the N-terminal tetrapeptide (AVPI) of SMAC to selected BIR domains of the IAPs. Small molecule compounds that mimic the AVPI motif of SMAC have been designed to overcome IAP-mediated apoptosis resistance of cancer cells. Here, we report the preclinical characterization of birinapant (TL32711), a bivalent SMAC-mimetic compound currently in clinical trials for the treatment of cancer. Birinapant bound to the BIR3 domains of cIAP1, cIAP2, XIAP, and the BIR domain of ML-IAP in vitro and induced the autoubiquitylation and proteasomal degradation of cIAP1 and cIAP2 in intact cells, which resulted in formation of a RIPK1:caspase-8 complex, caspase-8 activation, and induction of tumor cell death. Birinapant preferentially targeted the TRAF2-associated cIAP1 and cIAP2 with subsequent inhibition of TNF-induced NF-κB activation. The activity of a variety of chemotherapeutic cancer drugs was potentiated by birinapant both in a TNF-dependent or TNF-independent manner. Tumor growth in multiple primary patient-derived xenotransplant models was inhibited by birinapant at well-tolerated doses. These results support the therapeutic combination of birinapant with multiple chemotherapies, in particular, those therapies that can induce TNF secretion.

High-risk human papillomavirus detection in oropharyngeal, nasopharyngeal, and oral cavity cancers: comparison of multiple methods.

IMPORTANCE: Human papillomaviruses are now recognized as an etiologic factor in a growing subset of head and neck cancers and have critical prognostic importance that affects therapeutic decision making. There is no universally accepted gold standard for high-risk HPV (hrHPV) assessment in formalin-fixed, paraffin-embedded (FFPE) tissue specimens, nor is there a clear understanding of the frequency or role of hrHPV in sites other than oropharynx. OBJECTIVE: To determine the optimal assessment of hrHPV in FFPE head and neck tumor tissue specimens. DESIGN, SETTING, PARTICIPANTS: In the setting of a large Midwestern referral center, assessment of hrHPV by p16 immunohistochemical staining, in situ hybridization, and polymerase chain reaction (PCR)-MassArray (PCR-MA), with L1 PGMY-PCR and sequencing to resolve method discordance, was conducted for 338 FFPE oropharyngeal, nasopharyngeal, and oral cavity tumor tissue specimens. Relative sensitivity and specificity were compared to develop a standard optimal test protocol. Tissue specimens were collected from 338 patients with head and neck cancer treated during the period 2001 through 2011 in the departments of Otolaryngology, Radiation Oncology, and Medical Oncology. INTERVENTION: Patients received standard therapy. MAIN OUTCOMES AND MEASURES: Optimal hrHPV identification, detection, and activity in head and neck cancers. RESULTS: Using combined PCR-MA with L1 PGMY-PCR and sequencing for conclusive results, we found PCR-MA to have 99.5% sensitivity and 100% specificity, p16 to have 94.2% sensitivity and 85.5% specificity, and in situ hybridization to have 82.9% sensitivity and 81.0% specificity. Among HPV-positive tumors, HPV16 was most frequently detected, but 10 non-HPV16 types accounted for 6% to 50% of tumors, depending on the site. Overall, 86% of oropharynx, 50% of nasopharynx, and 26% of oral cavity tumors were positive for hrHPV. CONCLUSIONS AND RELEVANCE: PCR-MA has a low DNA (5 ng) requirement effective for testing small tissue samples; high throughput; and rapid identification of HPV types, with high sensitivity and specificity. PCR-MA together with p16INK4a provided accurate assessment of HPV presence, type, and activity and was determined to be the best approach for HPV testing in FFPE head and neck tumor tissue specimens.

Targeting Wnt-driven cancer through the inhibition of Porcupine by LGK974.

Wnt signaling is one of the key oncogenic pathways in multiple cancers, and targeting this pathway is an attractive therapeutic approach. However, therapeutic success has been limited because of the lack of therapeutic agents for targets in the Wnt pathway and the lack of a defined patient population that would be sensitive to a Wnt inhibitor. We developed a screen for small molecules that block Wnt secretion. This effort led to the discovery of LGK974, a potent and specific small-molecule Porcupine (PORCN) inhibitor. PORCN is a membrane-bound O-acyltransferase that is required for and dedicated to palmitoylation of Wnt ligands, a necessary step in the processing of Wnt ligand secretion. We show that LGK974 potently inhibits Wnt signaling in vitro and in vivo, including reduction of the Wnt-dependent LRP6 phosphorylation and the expression of Wnt target genes, such as AXIN2. LGK974 is potent and efficacious in multiple tumor models at well-tolerated doses in vivo, including murine and rat mechanistic breast cancer models driven by MMTV-Wnt1 and a human head and neck squamous cell carcinoma model (HN30). We also show that head and neck cancer cell lines with loss-of-function mutations in the Notch signaling pathway have a high response rate to LGK974. Together, these findings provide both a strategy and tools for targeting Wnt-driven cancers through the inhibition of PORCN.

Epidermal growth factor receptor, p16, cyclin D1, and p53 staining patterns for inverted papilloma.

BACKGROUND: The aim of this study was better characterize the staining patterns of inverted papilloma (IP) with and without carcinoma by performing immunohistochemistry for p16, epidermal growth factor receptor (EGFR), p53, and cyclin D1 antibodies in a large patient cohort. METHODS: A total of 162 IP specimens were collected from 147 patients treated at the University of Michigan between 1996 and 2011. Twenty-two specimens contained carcinoma. Tumor was extracted for construction of 2 tissue microarrays and stained for p16, EGFR, p53, and cyclin D1. Tumor staining intensity and percentage staining were scored. RESULTS: Benign disease was positive for p16 in 64%, EGFR in 50%, p53 in 30%, and cyclin D1 in 76%. IP with carcinomatous degeneration was positive for p16 in 14%, EGFR in 71%, p53 in 62%, and cyclin D1 in 76%. The differences in staining positivity between benign and malignant disease reached significance for p16 and p53 only. Mean percentage staining by tumor surface area for IP and IP with carcinoma was 12% vs 7% for p16 (no statistical significance [NS]), 20% vs 34% for EGFR (NS), 4% vs 24% for p53 (p < 0.001), and 17% vs 21% for cyclin D1 (NS). CONCLUSION: Important characteristic staining pattern for IP with and without carcinoma are highlighted in this study. Unlike recent trends in human papilloma virus (HPV)-related head and neck malignancies, low expression of p16 is a marker for malignancy in this series. Positive staining for p53 correlates with the development of carcinoma in IP.

Temporal and spatial evolution of therapy-induced tumor apoptosis detected by caspase-3-selective molecular imaging.

PURPOSE: Induction of apoptosis in tumors is considered a desired goal of anticancer therapy. We investigated whether the dynamic temporal and spatial evolution of apoptosis in response to cytotoxic and mechanism-based therapeutics could be detected noninvasively by the caspase-3 radiotracer [(18)F]ICMT-11 and positron emission tomography (PET). EXPERIMENTAL DESIGN: The effects of a single dose of the alkylating agent cyclophosphamide (CPA or 4-hydroperoxycyclophosphamide), or the mechanism-based small molecule SMAC mimetic birinapant on caspase-3 activation was assessed in vitro and by [(18)F]ICMT-11-PET in mice bearing 38C13 B-cell lymphoma, HCT116 colon carcinoma, or MDA-MB-231 breast adenocarcinoma tumors. Ex vivo analysis of caspase-3 was compared to the in vivo PET imaging data. RESULTS: Drug treatment increased the mean [(18)F]ICMT-11 tumor uptake with a peak at 24 hours for CPA (40 mg/kg; AUC40-60: 8.04 ± 1.33 and 16.05 ± 3.35 %ID/mL × min at baseline and 24 hours, respectively) and 6 hours for birinapant (15 mg/kg; AUC40-60: 20.29 ± 0.82 and 31.07 ± 5.66 %ID/mL × min, at baseline and 6 hours, respectively). Voxel-based spatiotemporal analysis of tumor-intrinsic heterogeneity suggested that discrete pockets of caspase-3 activation could be detected by [(18)F]ICMT-11. Increased tumor [(18)F]ICMT-11 uptake was associated with caspase-3 activation measured ex vivo, and early radiotracer uptake predicted apoptosis, distinct from the glucose metabolism with [(18)F]fluorodeoxyglucose-PET, which depicted continuous loss of cell viability. CONCLUSION: The proapoptotic effects of CPA and birinapant resulted in a time-dependent increase in [(18)F]ICMT-11 uptake detected by PET. [(18)F]ICMT-11-PET holds promise as a noninvasive pharmacodynamic biomarker of caspase-3-associated apoptosis in tumors.

UM-SCC-104: a new human papillomavirus-16-positive cancer stem cell-containing head and neck squamous cell carcinoma cell line.

BACKGROUND: Few human papillomavirus (HPV)(+) head and neck squamous cell carcinoma (HNSCC) cell lines exist. We established University of Michigan-squamous cell carcinoma-104 (UM-SCC-104), a new HPV(+) HNSCC cell line from a recurrent oral cavity tumor, and characterized it for the presence of cancer stem cells (CSCs). METHODS: Tumor cells were tested for biomarker expression by immunohistology, and the presence of HPV was assessed by several methods. RESULTS: UM-SCC-104 has a unique genotype, contains HPV-16, and expresses E6/E7. Inoculation of aldehyde dehydrogenase (ALDH)(+) and ALDH(-) cells in an immunocompromised mouse resulted in tumor growth from the ALDH(+) cells after 6 weeks that recapitulated the histology of the primary, whereas ALDH(-) cells did not produce tumors. CONCLUSION: UM-SCC-104, a new HPV-16, CSC-containing HNSCC cell line will aid in studying recurrent HPV(+) tumors. The aggressive nature of this tumor is consistent with high uniform expression of epidermal growth factor receptor (EGFR) and a functionally significant proportion of ALDH(+) CSCs.

Silencing heat shock protein 27 decreases metastatic behavior of human head and neck squamous cell cancer cells in vitro.

The small heat shock protein 27 (Hsp27) is a molecular chaperone that is involved in a variety of cellular functions in cancer cells. The purpose of this research is to study Hsp27 in vitro metastatic behaviors of head and neck squamous cell carcinoma cells (HNSCC). The expression of Hsp27 in primary and metastatic cell lines derived from the primary HNSCC and a synchronous lymph node metastasis in the same patient was determined using real-time PCR and Western blotting. Proliferation of the primary and metastatic HNSCC cell lines was evaluated using the MTS proliferation assay. Metastatic behavior was assessed using migration and invasion assays. SiRNA knockdown of Hsp27 was performed in the highly migratory metastatic HNSCC cell line. MTS assays showed that the primary (UM-SCC-22A) and metastatic (UM-SCC-22B) HNSCC have similar proliferation rates. However, UM-SCC-22B derived from the metastasis showed 2.3- to 3.6-fold higher migration ability and 2-fold higher invasion ability than UM-SCC-22A. Real-time PCR demonstrated that Hsp27 mRNA is 22.4-fold higher in metastatic UM-SCC-22B than primary UM-SCC-22A. Similarly, Western blotting showed that Hsp27 is rarely detectable in UM-SCC-22A whereas UM-SCC-22B expresses a 25-fold higher level of Hsp27 protein. SiRNA-mediated knockdown of Hsp27 in UM-SCC-22B reduced Hsp27 mRNA expression by nearly 6-fold and protein expression by 23-fold. Furthermore, siRNA knockdown of Hsp27 decreased metastatic behaviors of UM-SCC-22B by 3- to 4-fold in migration and 2-fold in cell invasion reducing cell invasion and migration to levels similar to the primary HNSCC UM-SCC-22A. These data indicate that Hsp27 may regulate metastatic potential of HNSCC cancer cells. Targeting Hsp27 may decrease metastasis in head and neck squamous cell cancer cells.

Genotyping of 73 UM-SCC head and neck squamous cell carcinoma cell lines.

BACKGROUND: We established multiple University of Michigan Squamous Cell Carcinoma (UM-SCC) cell lines. With time, these have been distributed to other labs all over the world. Recent scientific discussions have noted the need to confirm the origin and identity of cell lines in grant proposals and journal articles. We genotyped the UM-SCC cell lines in our collection to confirm their unique identity. METHOD: Early-passage UM-SCC cell lines were genotyped and photographed. RESULTS: Thus far, 73 unique head and neck UM-SCC cell lines (from 65 donors, including 21 lines from 17 females) were genotyped. In 7 cases, separate cell lines were established from the same donor. CONCLUSIONS: These results will be posted on the UM Head and Neck SPORE Tissue Core website for other investigators to confirm that the UM-SCC cells used in their laboratories have the correct features. Publications using UM-SCC cell lines should confirm the genotype.

Oxaliplatin pharmacokinetics and pharmacodynamics in adult cancer patients with impaired renal function.

PURPOSE: To characterize the pharmacokinetics and pharmacodynamics of oxaliplatin in cancer patients with impaired renal function. EXPERIMENTAL DESIGN: Thirty-four patients were stratified by 24-h urinary creatinine clearance (CrCL) into four renal dysfunction groups: group A (control, CrCL, >or=60 mL/min), B (mild, CrCL, 40-59 mL/min), C (moderate, CrCL, 20-39 mL/min), and D (severe, CrCL, <20 mL/min). Patients were treated with 60 to 130 mg/m2 oxaliplatin infused over 2 h every 3 weeks. Pharmacokinetic monitoring of platinum in plasma, plasma ultrafiltrates, and urine was done during cycles 1 and 2. RESULTS: Plasma ultrafiltrate platinum clearance strongly correlated with CrCL (r2 = 0.712). Platinum elimination from plasma was triphasic, and maximal platinum concentrations (Cmax) were consistent across all renal impairment groups. However, only the beta-half-life was significantly prolonged by renal impairment, with values of 14.0 +/- 4.3, 20.3 +/- 17.7, 29.2 +/- 29.6, and 68.1 h in groups A, B, C, and D, respectively (P = 0.002). At a dose level of 130 mg/m2, the area under the concentration time curve increased in with the degree of renal impairment, with values of 16.4 +/- 5.03, 39.7 +/- 11.5, and 44.6 +/- 14.6 mug.h/mL, in groups A, B, and C, respectively. However, there was no increase in pharmacodynamic drug-related toxicities. Estimated CrCL using the Cockcroft-Gault method approximated the measured 24-h urinary CrCL (mean prediction error, -5.0 mL/min). CONCLUSIONS: Oxaliplatin pharmacokinetics are altered in patients with renal impairment, but a corresponding increase in oxaliplatin-related toxicities is not observed.

Dose-escalating and pharmacologic study of oxaliplatin in adult cancer patients with impaired hepatic function: a National Cancer Institute Organ Dysfunction Working Group study.

PURPOSE: To determine the toxicities, pharmacokinetics, and maximally tolerated doses of oxaliplatin in patients with hepatic impairment and to develop formal guidelines for oxaliplatin dosing in this patient population. EXPERIMENTAL DESIGN: Sixty adult cancer patients with variable hepatic function received i.v. oxaliplatin ranging from 60 to 130 mg/m(2) every 3 weeks. Patients were stratified by levels of total bilirubin, aspartate aminotransferase (AST), and alkaline phosphatase (AP) into five cohorts based on the degree of hepatic dysfunction: control group A [bilirubin, AST, and AP < or = upper limit of normal (ULN)], mild dysfunction group B (bilirubin < or = ULN, ULN < AST < or = 2.5 x ULN, or ULN < AP < or = 5 x ULN), moderate dysfunction group C (ULN < bilirubin < or = 3.0 mg/dL, AST > 2.5 x ULN, or AP > 5 x ULN), severe dysfunction group D (bilirubin > 3.0 mg/dL, any AST, and any AP), and liver transplantation group E (any bilirubin, any AST, and any AP). Doses were escalated in cohorts of three patients, and urine and plasma ultrafiltrates were assayed for platinum concentrations. RESULTS: Dose escalation of single-agent oxaliplatin to 130 mg/m(2) was well tolerated in all cohorts. Platinum clearance did not correlate with any liver function test. Two of 56 assessable patients with a diagnosis of laryngeal carcinoma and cervical adenocarcinoma experienced partial responses lasting 3 and 5.5 months. CONCLUSIONS: Oxaliplatin at 130 mg/m(2) every 3 weeks was well tolerated in all patients with impaired liver function. Dose reductions of single-agent oxaliplatin are not indicated in patients with hepatic dysfunction.

Molecular, biologic, and pharmacokinetic properties of monoclonal antibodies: impact of these parameters on early clinical development.

Currently, 14 intact, unconjugated, monoclonal antibodies (Mabs) are approved for therapeutic use in the United States, and more than 100 Mabs are presently undergoing clinical development or regulatory review. Mabs are large molecular weight glycoproteins that embody structural, biochemical, and pharmacologic properties distinct from other biologics or chemically synthesized compounds. Early therapeutic Mabs were murine proteins, and clinical testing of these agents revealed serious immune-mediated toxicities. The side effect profile of murine Mab therapeutic agents restricted the clinical development of these agents to indications with high morbidity and/or mortality (ie, oncology, graft vs host rejection). Advances in genetic engineering and protein expression technologies resulted in the development of Mabs composed either predominately (ie, mouse/human chimeric, "humanized") or completely (ie, "fully human" Mabs) of the human amino acid sequence. The production of chimeric, humanized, and fully human Mabs significantly reduced the immune-mediated toxicities and expanded the utility for these agents in numerous therapeutic areas, particularly in chronic disorders requiring either long-term administration (ie, rheumatoid arthritis) or treatment upon the flare up of disease (Crohn's disease, psoriasis). This review provides an overview of the molecular, biochemical, and pharmacokinetic properties and clinical development history of Mabs and details how these factors currently affect the scope and design of early clinical development strategies for these drug candidates. Emphasis is placed on the criteria for selecting appropriate subject populations for phase I testing of Mabs.

Methamphetamine-induced sensitization differentially alters pCREB and DeltaFosB throughout the limbic circuit of the mammalian brain.

Enhancements in behavior that accompany repeated, intermittent administration of abused drugs (sensitization) endure long after drug administration has ceased. Such persistence reflects changes in intracellular signaling cascades and associated gene transcription factors in brain regions that are engaged by abused drugs. This process is not characterized for the most potent psychomotor stimulant, methamphetamine. Using motor behavior as an index of brain state in rats, we verified that five once-daily injections of 2.5 mg/kg methamphetamine induced behavioral sensitization that was demonstrated (expressed) 3 and 14 days later. Using immunoblot procedures, limbic brain regions implicated in behavioral sensitization were assayed for extracellular signal-regulated kinase and its phosphorylated form (pERK/ERK, a signal transduction kinase), cAMP response element binding protein and its phosphorylated form (pCREB/CREB, a constitutively expressed transcriptional regulator), and DeltaFosB (a long-lasting transcription factor). pERK, ERK, and CREB levels were not changed for any region assayed. In the ventral tegmental area, pCREB and DeltaFosB also were not changed. pCREB (activated CREB) was elevated in the frontal cortex at 3 days withdrawal, but not at 14 days. pCREB levels were decreased at 14 days withdrawal in the nucleus accumbens and ventral pallidum. Accumbal and pallidal levels of DeltaFosB were increased at 3 days withdrawal, and this increase persisted to 14 days in the pallidum. Thus, only the ventral pallidum showed changes in molecular processes that consistently correlated with motor sensitization, revealing that this region may be associated with this enduring behavioral phenotype initiated by methamphetamine. The present findings expand our understanding of the neuroanatomical and molecular substrates that may play a role in the persistence of druginduced sensitization.