Subjective effects and perceived mechanisms of change of cognitive behavioral and mindfulness-based online interventions for low sexual desire in women

Cognitive-behavioral (CBT) and mindfulness-based therapy (MBT) are effective treatments for Hypoactive Sexual Desire Dysfunction (HSDD) in women. To date, evidence regarding the mechanisms of these treatments for improving low sexual desire is still lacking. To gain comprehensive information on the subjective effects and perceived mechanisms of change of CBT and MBT for HSDD, semi-structured qualitative interviews were conducted with 51 cis-women who participated in a trial investigating internet-based CBT and MBT for HSDD. Data were analyzed with deductive and inductive content analysis. Subjective treatment effects included increased desire, improved communication, and greater self-acceptance. Different mechanisms of change for CBT and MBT were endorsed by participants. This study provides tangible evidence of the different pathways through which CBT and MBT can improve women's sexual desire.

A Qualitative Study of Women's Experiences with Cognitive-Behavioral and Mindfulness-Based Online Interventions for Low Sexual Desire

Cognitive-behavioral (CBT) and mindfulness-based therapy (MBT) are among the most researched types of psychological interventions for low sexual desire in women. While both have been found effective in improving women's sexual desire, little is known about how women personally experience these treatments. To closely examine both approaches from a participant's perspective, semi-structured telephone-based interviews were conducted with 51 cis-women (M_age = 39, SD = 11, range = 22 to 69) who participated in a randomized controlled study comparing internet-based CBT and MBT for low sexual desire with a waitlist. Interview data were analyzed using thematic and content analysis. Most women (n = 44, 86.3%) evaluated their respective treatment (i.e., CBT or MBT) as helpful in improving their sexual desire. CBT-techniques, such as cognitive restructuring, were mentioned as being helpful for challenging maladaptive thinking patterns, while formal mindfulness-exercises allowed women to disengage from negative sexuality-related thoughts. Elements of sex therapy, including self-stimulation exercises and sensate focus, were perceived as crucial for getting women in touch with their sexual desires and preferences. Strengths of the online format included anonymity, flexibility, and convenient access. Overall, women's personal accounts supported feasibility, acceptability, and clinical usefulness of CBT- and MBT-based internet interventions targeting low sexual desire.

Polygenic risk scores across the extended psychosis spectrum

As early detection of symptoms in the subclinical to clinical psychosis spectrum may improve health outcomes, knowing the probabilistic susceptibility of developing a disorder could guide mitigation measures and clinical intervention. In this context, polygenic risk scores (PRSs) quantifying the additive effects of multiple common genetic variants hold the potential to predict complex diseases and index severity gradients. PRSs for schizophrenia (SZ) and bipolar disorder (BD) were computed using Bayesian regression and continuous shrinkage priors based on the latest SZ and BD genome-wide association studies (Psychiatric Genomics Consortium, third release). Eight well-phenotyped groups (n = 1580; 56% males) were assessed: control (n = 305), lower (n = 117) and higher (n = 113) schizotypy (both groups of healthy individuals), at-risk for psychosis (n = 120), BD type-I (n = 359), BD type-II (n = 96), schizoaffective disorder (n = 86), and SZ groups (n = 384). PRS differences were investigated for binary traits and the quantitative Positive and Negative Syndrome Scale. Both BD-PRS and SZ-PRS significantly differentiated controls from at-risk and clinical groups (Nagelkerke's pseudo-R2: 1.3-7.7%), except for BD type-II for SZ-PRS. Out of 28 pairwise comparisons for SZ-PRS and BD-PRS, 9 and 12, respectively, reached the Bonferroni-corrected significance. BD-PRS differed between control and at-risk groups, but not between at-risk and BD type-I groups. There was no difference between controls and schizotypy. SZ-PRSs, but not BD-PRSs, were positively associated with transdiagnostic symptomology. Overall, PRSs support the continuum model across the psychosis spectrum at the genomic level with possible irregularities for schizotypy. The at-risk state demands heightened clinical attention and research addressing symptom course specifiers. Continued efforts are needed to refine the diagnostic and prognostic accuracy of PRSs in mental healthcare.

Using Three Indirect Measures to Assess the Role of Sexuality-Related Associations and Interpretations for Women's Sexual Desire: An Internet-Based Experimental Study

Theoretical models emphasize the role of both automatic appraisals (i.e., associations) and conscious appraisals (i.e., interpretations) for sexual desire. Studies on sexuality-related appraisals have not combined self-report measures and experimental paradigms in order to compare the relevance of associations or interpretations. The aim of this study was to assess the relative contribution of both associations and interpretations to the explanation of low sexual desire in women. Toward this goal, indirect measures assessing associations (via a Single Target Implicit Association Test [STIAT]) and interpretations (via a Scrambled Sentences Test [SST] and a scenario task) were administered in a sample of 263 women (M_age = 27.90, SD 8.27) with varying levels of sexual desire and different sexual orientations (exclusively heterosexual women: 54.6%). Negative sexuality-related interpretations as assessed with two variants of the SST as well as the scenario task added to the explanation of lower sexual desire in women. Negative associations as measured with the STIAT were predictive of lower sexual desire only in women who did not indicate an exclusively heterosexual orientation. In this study, sexuality-related interpretations were more relevant to women's sexual desire than automatic associations. Future studies should assess the causal mechanism underlying sexuality-related interpretations (e.g., by evaluating whether these can be changed via cognitive bias modification techniques or psychological treatments).

Psychometric Properties of a Self-Report Version of the Sexual Interest and Desire Inventory-Female (SIDI-F-SR)

BACKGROUND

The Sexual Interest and Desire Inventory-Female (SIDI-F) is a clinician-administered scale that allows for a comprehensive assessment of symptoms related to Hypoactive Sexual Desire Dysfunction (HSDD). As self-report questionnaires may facilitate less socially desirable responding and as time and resources are scarce in many clinical and research settings, a self-report version was developed (Sexual Interest and Desire Inventory- Female Self-Report; SIDI-F-SR).

AIM

To assess the psychometric properties of the SIDI-F-SR and to investigate the agreement between the SIDI-F and SIDI-F-SR.

METHODS

A total of 170 women (Mage = 37, SD = 11, range = 20-69) with HSDD answered the SIDI-F, administered by a clinical psychologist via telephone, first, followed by the SIDI-F-SR, delivered as an Internet-based questionnaire. A subset of 19 women answered the SIDI-F-SR twice over a period of 14 weeks.

OUTCOMES

Convergent validity of the SIDI-F-SR was assessed via correlations with the desire subscale of the Female Sexual Function Index and the Female Sexual Distress Scale Revised. Internal consistency and test-retest reliability as well as intraclass correlation and predictors of absolute agreement between SIDI-F and SIDI-F-SR were examined.

RESULTS

Test-retest-reliability was good (r = 0.74). Convergent validity was low but comparable between SIDI-F and SIDI-F-SR. Internal consistency of the SIDI-F-SR was acceptable (α = 0.76) and comparable to the SIDI-F (α = 0.74). When corrections for the restriction of range were applied, internal consistency of the SIDI-F-SR increased to 0.91. There was high agreement between SIDI-F and SIDI-F-SR (ICC = 0.86). On average, women scored about one point higher (indicated more desire) in the self-report vs the clinician-administered scale.

CLINICAL IMPLICATIONS

The SIDI-F-SR can be used in settings where time and resources are limited. Whether the clinical cutoff point for the SIDI-F is adequate for the SIDI-F-SR has yet to be determined.

STRENGTHS AND LIMITATIONS

Large sample of diverse women with HSDD. Lack of control groups (ie, healthy controls, women with other sexual dysfunctions).

CONCLUSION

The SIDI-F-SR showed promising psychometric properties in a sample of women with HSDD. Velten J, Hirschfeld G, Meyers M, et al. Psychometric Properties of a Self-Report Version of the Sexual Interest and Desire Inventory-Female (SIDI-F-SR). J Sex Med 2021;18:990-995.

Psychological Treatment of Low Sexual Desire in Women: Protocol for a Randomized, Waitlist-Controlled Trial of Internet-Based Cognitive Behavioral and Mindfulness-Based Treatments

BACKGROUND

Psychological therapies are effective treatments for hypoactive sexual desire dysfunction (HSDD; formerly hypoactive sexual desire disorder), a common sexual dysfunction among women. Access to evidence-based treatments, however, remains difficult. Internet-based interventions are effective for a variety of psychological disorders and may be a promising means to close the treatment gap for HSDD.

OBJECTIVE

This article describes the treatment protocol and study design of a randomized controlled trial, aiming to study the efficacy of cognitive behavioral and mindfulness-based interventions delivered via the internet for women with HSDD to a waitlist control group. Outcomes are sexual desire (primary) and sexual distress (secondary). Additional variables (eg, depression, mindfulness, rumination) will be assessed as potential moderators or mediators of treatment success.

METHODS

A cognitive behavioral and a mindfulness-based self-help intervention for HSDD will be provided online. Overall, 266 women with HSDD will be recruited and assigned either to one of the intervention groups, or to a waitlist control group (2:2:1). Outcome data will be assessed at baseline, at 12 weeks, and at 6 and 12 months after randomization. Intention-to-treat and completer analyses will be conducted.

RESULTS

We expect improvements in sexual desire and sexuality-related distress in both intervention groups compared to the waitlist control. Recruitment has begun in January 2019 and is expected to be completed in August 2021. Results will be published in 2022.

CONCLUSIONS

This study aims to contribute to the improvement and dissemination of psychological treatments for women with HSDD and to clarify whether cognitive behavioral and/or mindfulness-based treatments for HSDD are feasible and effective when delivered via the internet.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03780751; https://clinicaltrials.gov/ct2/show/NCT03780751.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/20326.

An Investigation of Psychosis Subgroups With Prognostic Validation and Exploration of Genetic Underpinnings: The PsyCourse Study

IMPORTANCE

Identifying psychosis subgroups could improve clinical and research precision. Research has focused on symptom subgroups, but there is a need to consider a broader clinical spectrum, disentangle illness trajectories, and investigate genetic associations.

OBJECTIVE

To detect psychosis subgroups using data-driven methods and examine their illness courses over 1.5 years and polygenic scores for schizophrenia, bipolar disorder, major depression disorder, and educational achievement.

DESIGN, SETTING, AND PARTICIPANTS

This ongoing multisite, naturalistic, longitudinal (6-month intervals) cohort study began in January 2012 across 18 sites. Data from a referred sample of 1223 individuals (765 in the discovery sample and 458 in the validation sample) with DSM-IV diagnoses of schizophrenia, bipolar affective disorder (I/II), schizoaffective disorder, schizophreniform disorder, and brief psychotic disorder were collected from secondary and tertiary care sites. Discovery data were extracted in September 2016 and analyzed from November 2016 to January 2018, and prospective validation data were extracted in October 2018 and analyzed from January to May 2019.

MAIN OUTCOMES AND MEASURES

A clinical battery of 188 variables measuring demographic characteristics, clinical history, symptoms, functioning, and cognition was decomposed using nonnegative matrix factorization clustering. Subtype-specific illness courses were compared with mixed models and polygenic scores with analysis of covariance. Supervised learning was used to replicate results in validation data with the most reliably discriminative 45 variables.

RESULTS

Of the 765 individuals in the discovery sample, 341 (44.6%) were women, and the mean (SD) age was 42.7 (12.9) years. Five subgroups were found and labeled as affective psychosis (n = 252), suicidal psychosis (n = 44), depressive psychosis (n = 131), high-functioning psychosis (n = 252), and severe psychosis (n = 86). Illness courses with significant quadratic interaction terms were found for psychosis symptoms (R2 = 0.41; 95% CI, 0.38-0.44), depression symptoms (R2 = 0.28; 95% CI, 0.25-0.32), global functioning (R2 = 0.16; 95% CI, 0.14-0.20), and quality of life (R2 = 0.20; 95% CI, 0.17-0.23). The depressive and severe psychosis subgroups exhibited the lowest functioning and quadratic illness courses with partial recovery followed by reoccurrence of severe illness. Differences were found for educational attainment polygenic scores (mean [SD] partial η2 = 0.014 [0.003]) but not for diagnostic polygenic risk. Results were largely replicated in the validation cohort.

CONCLUSIONS AND RELEVANCE

Psychosis subgroups were detected with distinctive clinical signatures and illness courses and specificity for a nondiagnostic genetic marker. New data-driven clinical approaches are important for future psychosis taxonomies. The findings suggest a need to consider short-term to medium-term service provision to restore functioning in patients stratified into the depressive and severe psychosis subgroups.

A longitudinal approach to biological psychiatric research: The PsyCourse study

In current diagnostic systems, schizophrenia and bipolar disorder are still conceptualized as distinct categorical entities. Recently, both clinical and genomic evidence have challenged this Kraepelinian dichotomy. There are only few longitudinal studies addressing potential overlaps between these conditions. Here, we present design and first results of the PsyCourse study (N = 891 individuals at baseline), an ongoing transdiagnostic study of the affective-to-psychotic continuum that combines longitudinal deep phenotyping and dimensional assessment of psychopathology with an extensive collection of biomaterial. To provide an initial characterization of the PsyCourse study sample, we compare two broad diagnostic groups defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) classification system, that is, predominantly affective (n = 367 individuals) versus predominantly psychotic disorders (n = 524 individuals). Depressive, manic, and psychotic symptoms as well as global functioning over time were contrasted using linear mixed models. Furthermore, we explored the effects of polygenic risk scores for schizophrenia on diagnostic group membership and addressed their effects on nonparticipation in follow-up visits. While phenotypic results confirmed expected differences in current psychotic symptoms and global functioning, both manic and depressive symptoms did not vary between both groups after correction for multiple testing. Polygenic risk scores for schizophrenia significantly explained part of the variability of diagnostic group. The PsyCourse study presents a unique resource to research the complex relationships of psychopathology and biology in severe mental disorders not confined to traditional diagnostic boundaries and is open for collaborations.

At-risk symptoms of bipolar disorder in a university student cohort

To assess the occurrence and frequency of bipolar at-risk symptoms in a large sample of previously undiagnosed students using the new screening tool Bochumer Screeningbogen Bipolar (BSB). 2329 students of the Ruhr-University Bochum, Germany completed online demographic data as well as various self-rating questionnaires (BSB; Hypomania Checklist 32; Altman Self-Rating Mania Scale; Beck Depression Inventory). Within the student cohort (64.4% female, mean age 24.3 years) every fifth student currently suffered from moderate to severe depressive symptoms; every sixth student had already thought about suicide and every other student reported a history of mood swings. The most frequently reported depressive symptoms included physical exhaustion, depressed mood, and tiredness. The most frequently reported (hypo)manic symptoms included physical agitation, feeling extremely energetic, and lack of concentration. The BSB showed good convergent validity with other established questionnaires capturing depressive or (hypo)manic symptoms, as well as a stable administration of underlying constructs. The BSB correlated significantly with the already established applied questionnaires. The predictive power of the BSB regarding the development of bipolar disorder cannot be correctly quantified at present. The further purpose of this exploratory web-based study should be to examine the validity of the presented measures in a longitudinal design.

Multiple births by a captive swellshark Cephaloscyllium ventriosum via facultative parthenogenesis

Using a novel set of 12 microsatellites, a captive, adult female swellshark Cephaloscyllium ventriosum that produced five pups via parthenogenesis is described; naturally occurring parthenogenesis has been observed in every vertebrate class with the exception of mammals. As demonstrated in this study, a captive environment is ideal for long-term monitoring of animals under controlled conditions, and easily allows the detection of particular facets of their biology.

Large Group Exposure Treatment: A Feasibility Study of Exposure Combined with Diaphragmatic Breathing in Highly Dental Fearful Individuals

A large-group one session treatment (LG-OST) combining exposure and diaphragmatic breathing as a bodily coping element was carried out to investigate its feasibility and effectiveness in a sample of 43 highly dental fearful individuals treated simultaneously. We assessed subjective dental fear, dysfunctional dental-related beliefs, and perceived control pre- and post-intervention and at four-month follow-up. Participants additionally performed a behavioural approach test (BAT) pre- and post-intervention. During the applied exposure exercises, four participants (9.3%) discontinued the program all reporting too high levels of distress. Regarding subjective dental fear and dysfunctional dental related beliefs post treatment effects, LG-OST showed medium to large effect sizes, ranging from Cohen's d = 0.51 to d = 0.84 in the Intention-to-Treat analysis. Subjective dental fear improved clinically significantly in about one fourth (25.6%) of therapy completers. All post-treatment effects remained stable over time. Concerning the behavioral fear dimension, we observed a strong ceiling effect. Already at pre-assessment, participants accomplished more than six out of seven BAT-steps. Thus, behavioral approach did not increase significantly following treatment. Overall, the LG-OST protocol proved feasible and efficient. Compared to other one-session individual and multi-session group treatments the observed LG-OST effects were smaller. However, if LG-OST could match the efficacy of highly intensive short treatments delivered in an individual setting in the future, for example, by applying a wider array of exposure exercises, it could be a very useful treatment option as an intermediate step within a stepped care approach.

Abstract P2-11-11: Phase II trial of exemestane with immunomodulatory oral cyclophosphamide in metastatic hormone receptor (HR)-positive breast cancer: Prolonged progression-free survival (PFS) in patients with distinct T regulatory cell (Treg) profile

Background: Resistance to endocrine therapies in HR-positive breast cancer is a significant challenge. The steroidal aromatase inhibitor (AI) exemestane (EXE) has demonstrated short-term efficacy in metastatic HR-positive HER2-negative breast cancer (mHR+BC) that has progressed during treatment with a non-steroidal AI. Combination strategies have not shown a survival benefit. Immunotherapy represents a promising approach as it may increase durability of responses. Low dose cyclophosphamide (CTX) has demonstrated efficacy in combination with neoadjuvant letrozole in HR+BC, conceivably by enhancing anti-tumor immune responses. Here we investigated whether EXE combined with immunomodulatory CTX could provide durable responses in heavily pretreated patients and assessed immunological profiles (NCT01963481).

Methods: Phase II trial of EXE (25mg PO daily) with CTX (50 mg PO daily) enrolled postmenopausal women (n=23) with mHR+BC who had progressed on prior endocrine therapy (including nonsteroidal AI, tamoxifen, and/or fulvestrant); prior chemotherapy was allowed. The primary endpoint was PFS (per RECIST 1.1) at 3 months; secondary endpoints were response rate, tolerability, and immune correlates. Detailed functional immune profiling of peripheral T cell subsets were performed by flow cytometry at baseline, 1, 3, 6, 9 & 12 months, with healthy donors available as controls.

Results: All 23 patients have been enrolled, and 21 are evaluable for response. Median age was 54 (range 31-77), median prior lines of endocrine therapy was 2 (1-3) and chemotherapy was 1 (0-5). The majority (15/23) had visceral organ involvement. Combination treatment was well tolerated with one grade 3 urinary tract infection but no grade 4 or 5 toxicity. An objective response was observed in 19% of patients (4/21, 1 CR and 3 PR) and an additional 33% (7/21) had SD, resulting in a 3-month-PFS of 48.5% (95% CI, 30.5-77.1). Responses were durable in all patients, lasting =/> 9 months and included patients with liver metastases.

Comparison of peripheral immune cell subsets of patients (n=16) at baseline to age/sex-matched healthy controls demonstrated an increased proportion of CD4+ memory T cells with central memory phenotype (CD45RO+CD27+, p<0.0001). When patients were stratified based on PFS at 3 months, the proportion of naïve Tregs (CD4+CD45RO-FOXP3+Helios+) at baseline was significantly lower (p=0.003) in the non-progressor group compared to patients with progression. Remarkably, when these patient groups were compared for changes in T cell subsets during treatment, the proportion of both naïve and memory Treg subsets increased from baseline to 3 months (p<0.01), but only in the non-progressor patient group. While preliminary, these findings are possibly indicative of novel predictive biomarkers.

Conclusion: EXE and CTX had a favorable safety profile with evidence of clinical activity in patients with heavily pretreated mHR+BC, including durable responses in liver and bone. Correlative studies are ongoing to identify potential biomarkers of response or resistance to therapy.

Citation Format: Kwa M, Novik Y, Oratz R, Jhaveri K, Wu J, Gu P, Meyers M, Muggia F, Bonakdar M, Abidoglu C, Kozhaya L, Li X, Joseph B, Iwano A, Friedman K, Goldberg JD, Unutmaz D, Adams S. Phase II trial of exemestane with immunomodulatory oral cyclophosphamide in metastatic hormone receptor (HR)-positive breast cancer: Prolonged progression-free survival (PFS) in patients with distinct T regulatory cell (Treg) profile. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-11-11.

Head and neck adenoid cystic carcinoma: A prospective multicenter REFCOR study of 95 cases

OBJECTIVES

To describe the clinical, histological and therapeutic characteristics of a prospective multicenter series of 95 head and neck adenoid cystic carcinoma patients, and to determine any prognostic factors for disease-free survival.

PATIENTS AND METHODS

Ninety-five patients with adenoid cystic carcinoma were included in the Réseau d'Expertise Français Des Cancers ORL Rares (REFCOR, French Rare Head and Neck Cancer Expert Network) database between 2009 and 2012. The primary site was the salivary glands in 39 cases, sinus cavities (including hard palate) in 36 cases, pharynx-larynx-trachea in 14 cases, and lips and oral cavity in 4 cases. The tumor was stage I in 15% of cases, stage II in 23%, stage III in 26% and stage IV in 36%. Nine patients had cervical lymph node involvement and 5 had metastases at diagnosis. Fifty-six percent of patients were managed by surgery with postoperative radiation therapy. During follow-up, 3 patients died, 9 developed metastases and 12 showed recurrence or local progression.

RESULTS

Mean follow-up was 18 months. On univariate analysis, disease-free survival correlated with T stage (P=0.05), N stage (P=0.003), resection margins (P=0.04), lymph node involvement on histology (P=0.01), and absence of chemotherapy (P=0.03). On multivariate analysis, disease-free survival correlated with T stage (P=0.01), N stage (P=0.09) and surgery (P=0.005).

CONCLUSION

The essential issue in adenoid cystic carcinoma is long-term control. The present results confirm that the reference attitude is radical surgical resection for optimal local control. Adjuvant radiation therapy did not emerge as a prognostic factor. This study also provides a starting-point for translational studies in pathology and genetics.

Abstract P5-20-05: A Phase 2 trial of RAD 001 and Carboplatin in patients with triple negative metastatic breast cancer

BACKGROUND: RAD001 is an oral mTOR inhibitor that has exhibited activity in breast cancer. Triple negative breast cancer cells are unable to repair double stranded DNA breaks and hence have sensitivity to platinum agents that cause interstrand cross-links. Rapamycin acts synergistically with platinum agents to induce apoptosis and inhibit proliferation in at least two different breast cancer cell lines (including ER/PR negative cell lines). We propose that combination RAD001 and carboplatin may have activity in triple-negative breast cancer.

MATERIALS AND METHODS: The primary objective of the study is to determine clinical benefit (complete remission (CR) + partial remission (PR) + stable disease (SD more than 6 months)) and the toxicity of this combination in triple negative metastatic breast cancer who have had 0–3 prior chemotherapy regimens for metastatic disease. Twenty-five subjects were to be entered in this Phase II study. This design has greater than 80% power to test the null hypothesis that the clinical benefit rate is less than or equal to 10% versus the alternative hypothesis that clinical benefit rate is greater than or equal to 30%. Prior carboplatin is allowed. Women with treated brain metastasis are eligible. Secondary objectives are to determine progression free survival and relationship between pretreatment sensitivity (biopsy at baseline) and clinical response (biopsy post 2 cycles) using IHC staining for abundance of key proteins in the Akt-mTOR pathway and their activity using surrogate phosphorylation site-specific antibodies. According to the original study plan, carboplatin AUC 6, was to be given intravenously every three weeks. Five mg of RAD001 was to be given daily with a 3 patient run-in and then 10 mg daily if there were no dose-limiting toxicities. Due to a surprising amount of thrombocytopenia with this combination the dose of carboplatin was first amended to AUC 5 and most recently to AUC 4 with 5 mg of RAD001 (and no plan to escalate to 10 mg).

RESULTS: 23 patients of a planned 25 have been recruited thus far. Median age is 59. Of the 20 patients assessable for response at this time, there have been 1 CR, 5 PRs, 8 SDs and 6 PDs. One SD was achieved in a patient progressing on single agent Carboplatin at study entry. Median duration of CR+ SD +PR thus far is 13 weeks (range: 6–74 weeks). 5 of 22 patients assessable for toxicity had grade 3/4 thrombocytopenia and 4 patients had grade 3 neutropenia (no febrile neutropenia). 13 out of eighteen patients have had treatment held and/or dose reductions secondary to hematological toxicity, however, since amendment for starting dose of Carboplatin to AUC 4 the regimen has been very well tolerated with only 1 out of eleven patients with grade 3 neutropenia and grade 3 thrombocytopenia. 1 patient suffered from grade 3 dehydration. The estimated clinical benefit rate is 45% (95% confidence interval: 23%, 67%). Median time to progression or death is 85 days from start of treatment.

CONCLUSIONS: Our study has met the primary end point of demonstrating clinical benefit in triple negative metastatic breast cancer. Dose limiting thrombocytopenia was an unexpected side effect requiring protocol amendment. We continue to accrue study subjects at the amended dosing.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-20-05.

Evaluating systemic lupus erythematosus patients for lung involvement

Introduction: We set out to determine the frequency of respiratory symptoms, abnormal lung function, and shrinking lung syndrome (SLS) among patients with systemic lupus erythematosus (SLE) and to determine correlates of SLS. Methods: Consecutive adult patients who fulfilled the American College of Rheumatology classification criteria for SLE were enrolled. Demographics, clinical, and serologic characteristics were recorded; all patients underwent pulmonary function tests (PFT) and had either a chest X-ray or computed tomography scan. SLS was defined as dyspnea with restrictive lung physiology (defined as a forced vital capacity (FVC) <80% predicted in the absence of obstruction) who did not have any evidence of interstitial lung disease on chest imaging; controls were symptomatic patients with no restrictive physiology and the absence of interstitial changes on chest imaging. Results: Sixty-nine out of 110 (63%) patients had respiratory symptoms, 73 (66%) patients had abnormal lung function, and 11 (10%) patients met the definition for SLS. In a multivariate model controlling for disease duration, a history of pleuritis, modified American College of Rheumatology total score, seropositivity for dsDNA and RNP antibodies, increased disease duration (odds ratio (OR) = 1.2; 95% confidence interval (CI) of 1.0–1.3, p = 0.04), seropositivity for anti-RNP (OR = 24.4; 95% CI of 1.6–384.0, p = 0.02), and a history of serositis were significantly associated with SLS when compared with symptomatic controls. Conclusion: Respiratory symptoms, abnormal lung function, and SLS are common in SLE. Clinicians should consider evaluation for SLS among symptomatic patients with long-standing disease and a history of pleuritis.

P1-17-07: Phase II Trial of RAD001 Plus Carboplatin in Patients with Triple-Negative Metastatic Breast Cancer

Background: RAD001 is an oral mTOR inhibitor that has exhibited activity in breast cancer. Triple negative breast cancer cells are unable to repair double stranded DNA breaks and hence have sensitivity to platinum agents that cause interstrand cross-links. Rapamycin acts synergistically with platinum agents to induce apoptosis and inhibit proliferation in at least two different breast cancer cell lines (including ER/PR negative cell lines). We propose that combination RAD001 and carboplatin may have activity in triple-negative breast cancer.

Methods: The primary objective of the study is to determine clinical benefit (complete remission (CR) + partial remission (PR) + stable disease (SD)) and the toxicity of this combination in women with triple negative metastatic breast cancer who have had 0–3 prior chemotherapy regimens for metastatic disease. Secondary objectives are to determine progression free survival as well as investigating the relationship between pretreatment sensitivity (biopsy at baseline) and clinical response (biopsy post 2 cycles) using IHC staining for abundance of key proteins in the Akt-mTOR pathway and their activity using surrogate phosphorylation site-specific antibodies (Akt and phospho-serine 473, phospho-threonine and phospho-threonine 308 Akt; mTOR and phospho-serine 2448 mTOR; ribosome protein S6 kinase (S6K) and phospho-threonine 378 S6K; 4E-BP1 and phospho-serine 65 4E-BP1). Prior carboplatin is allowed. Women with treated brain metastasis are eligible. According to the original study plan, carboplatin AUC 6, was to be given intravenously every three weeks. Five mg of RAD001 was to be given daily with a 3 patient run-in and then 10 mg daily if there were no dose-limiting toxicities. Due to a unexpected amount of thrombocytopenia with this combination the dose of carboplatin was first amended to AUC 5 and most recently to AUC 4 with 5 mg of RAD001 (and no plan to escalate to 10 mg).

Results: Fourteen patients of a planned 25 have been recruited thus far. Median age is 58.5. Median number of prior regimens is 2 (0-3). Of the 7 patients assessable for response at this time, there have been 2 PR's and 5 patients with SD. One SD was achieved in a patient progressing on single agent carboplatin at study entry. Median duration of SD + PR is 28.5 weeks (5 patients have ongoing response ranging from 8–46.5 weeks). Five of 8 patients assessable for toxicity had grade 3 or 4 thrombocytopenia and 2 patients had grade 3 neutropenia. No cases of febrile neutropenia were observed. Four patients have required blood transfusion and one patient has required platelet transfusion. All patients have had treatment held and/or dose reductions secondary to hematological toxicity, however, since amended carboplatin dose the regimen has been very well tolerated with only one out of six patients) with grade 3 neutropenia and grade 3 thrombocytopenia. There have been no non-hematological grade 3 or 4 toxicities.

Conclusions: Clinical benefit was observed in all 7 assessable patients. Dose limiting thrombocytopenia was an unexpected side effect requiring protocol amendment. We continue to accrue study subjects at the amended dosing.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-17-07.

96 EFFECT OF DIETARY SUPPLEMENTATION WITH TUNA OIL ON THE LIPID COMPOSITION OF BOAR SPERMATOZOA AND CHARACTERISTICS OF SEMEN

In most mammals, docosahexaenoic acid (DHA) is the dominant polyunsaturated fatty acid (PUFA), although, in several species, docosapentaenoic acid is also a major component of the sperm cell membranes. The amount of DHA in spermatozoa is positively correlated with sperm motility. The effect of dietary supplementation with tuna oil (TO) on the lipid and fatty acid composition of boar spermatozoa and the relationship between the changes in composition and boar semen characteristics were studied. Twenty-four boars were distributed in a completely randomized factorial design (2 � 3) with two oil sources (soybean and tuna) and three levels of antioxidant (150, 300, and 450 mg of vitamin E/kg). The diets consisted of a basal diet that was supplemented with 30 g soybean or TO per kg diet. During a period of 10 weeks of feeding the diets, one ejaculate from each boar was collected per week. The sperm was diluted 1:1 with Beltsville thawing solution (BTS) and divided into three portions destined to cooling (5 and 17�C) and freezing. The sperm diluted for cooling at either temperature was stored in plastic bottles for 3 days. After dilution with BTS, the sperm for freezing was centrifuged and rediluted with freezing extender before it was stored in 0.5-mL straws. Thawing was achieved by placing the straws in a water bath (37�C) for 30 s. Motility, vigor, hypoosmotic swelling (host), and morphology were assessed. For determining the fatty acid composition of the spermatozoa and seminal plasma, a sample of 15 mL was taken from each ejaculate shortly after collection and centrifuged for 20 min at 1000g. Sperm motility and vigor were analyzed by placing a sample on a pre-warmed (37�C) microscopic slide, covering with a coverslip, and examining under a light microscope at a magnification of 200�. For host assessment in each case, a volume of 10 µL was mixed with 1 mL hypoosmotic solution (100 mOsm L–1) and incubated for 30 min in a water bath (37�C). After incubation, 50 µL of formol-saline was added to each tube. Sequentially, 20 µL of every sample was smeared on a microscope slide and observed with oil immersion using a phase contrast microscope. A minimum of 200 cells was observed and classified as non-coiled and coiled. Lipid peroxidation was measured using the thiobarbituric acid reaction. Treatment differences for sperm were determined using analysis of variance for means. The proportion of DHA in sperm phospholipid fatty acids increased in semen fatty acid composition after 1 week of feeding TO. The concentrations of the fatty acids were unchanged in the seminal plasma as a result of the diets fed. The proportion of spermatozoa with abnormal morphologies decreased in boars supplemented with TO (P < 0.05). The TO diet showed the lowest level of total antioxidants in the semen (P < 0.05); however, when the diet was supplemented with the higher vitamin E level, an increase in sperm motility and vigor was observed (P < 0.05). Therefore, dietary supplementation with TO alters the lipid composition of the membrane and has a beneficial effect on both cooled and cryopreserved boar spermatozoa by decreasing cold shock during cooling and thus increasing cryosurvival.

67 DELIVERING CHOLESTANOL OR DESMOSTEROL TO BULL SPERM MEMBRANES IMPROVES CRYOSURVIVAL

Altering the lipid composition of sperm plasma membranes affects sperm cryosurvival. Cryopreservation induces many stresses on the spermatozoa, including destabilization of the plasma membrane, which results in the loss of sperm motility and function. Treating bull spermatozoa with cholesterolloaded cyclodextrin (CLC) prior to cryopreservation increases sperm cryosurvival rates. This study compared the effect of adding other sterols, which should incorporate into the membrane and increase membrane fluidity at low temperatures, thereby increasing cryosurvival. Ejaculates from four bulls were divided into two experiments (E). In E1, ejaculates were extended with Tris, and then subdivided into four treatments: No additive (control), 1.5 mg CLC/120 million sperm (positive control), and 1.5 mg/120 million sperm in cyclodextrin pre-loaded with either cholestanol or desmosterol. Spermatozoa were incubated for 15 min at 22�C after which both the ability of fresh spermatozoa to bind to the zona pellucida (ZP) and chicken egg perivitelline membrane (EPM) and their osmotic tolerance were evaluated. In E2, sperm were diluted to 120 million cells mL–1 in a Tris diluent and treated as described for E1. Then, samples were diluted 1:1 (v:v) in Tris with 20% Egg Yolk (EY) and cooled to 5�C. After dilution 1:1 (v:v) with Tris containing 10% EY and 16% glycerol, samples were allowed to equilibrate for 15 min, and then were packaged into 0.5-mL straws, frozen in static liquid nitrogen vapor for 20 min, and plunged into liquid nitrogen for storage. Straws were thawed and the motility and zona-binding ability were determined using a Hamilton Thorne Motility Analyzer (Hamilton Thorne Biosciences, Beverly, MA, USA) and epifluorescence microscopy, respectively. Treatment differences for sperm motility, osmotic tolerance, and zona binding were determined using analysis of variance. Treating spermatozoa with CLC resulted in more fresh bull spermatozoa binding to the EPM and ZP compared to cholestanolor desmosterol-loaded cyclodextrin-treated spermatozoa or control cells (P < 0.05). No differences were observed between EPM and ZP binding (P > 0.05). The percentages of total and progressively motile spermatozoa were higher for fresh samples treated with cholesterol-, cholestanol-, or desmosterol-loaded cyclodextrin than for control cells (P < 0.05) when spermatozoa were exposed to anismotic conditions, and then returned to isosmolality. After cryopreservation, the percentages of motile spermatozoa and number of spermatozoa binding to ZP were similar for spermatozoa treated with CLC (56% and 115 sperm/ZP) and cholestanol (53% and 108 sperm/ZP) compared to spermatozoa treated with desmosterol (42% and 86 sperm/ZP; P < 0.05). All treatments provided higher motility and binding efficiency than control spermatozoa (32% and 62 sperm/ZP; P < 0.05). Therefore, adding cholesterol or cholestanol to bull sperm membranes improved cell cryosurvival. Studies to determine if cholestanol affects sperm capacitation need to be conducted.

A qualitative study of persons who are 100% adherent to antiretroviral therapy

This qualitative study examined the medication-taking behaviors and attitudes of participants determined to be 100% adherers to antiretroviral therapy from a NIH-funded study testing a 12-week telephone adherence intervention. Using open-ended questions, interviewers collected data on a sample of 13 informants, whose medication adherence to a randomly selected antiretroviral medication was 100%, based on a 30-day data collection using electronic event monitoring (EEM). The analysis revealed 'successful medication management' as the core category or main theme. The participants achieved success with medication adherence through managing specific areas (regimen, self and environment). By adopting realistic expectations and pragmatic attitudes, adherence is fostered when medication taking is a priority, when patients believe in the efficacy of their medications and when there is a strong patient/provider relationship. Future research is needed to develop tailored interventions using strategies identified by this population. Further in-depth examination of medication-taking behaviors in 100% adherers may be useful in developing individualized programs to maximize adherence to antiretroviral therapy in the clinical setting.

Liquid storage of flow cytometrically sorted ram spermatozoa

This study investigated the optimum short-term storage conditions for ram spermatozoa before and after flow cytometric sorting. Prior to sorting, semen from four rams (n = 3 ejaculates per ram) was diluted in either a Tris-based diluent (TRIS) or AndroHep (AH) and stored at 5, 15 or 21 degrees C for 0, 6 or 24h. Sperm characteristics were assessed during storage and after sorting, freeze-thawing and incubation (6h, 37 degrees C). Functional capacity and migration ability in artificial cervical mucus (sperm migration test (SMT)) of stored, sorted and non-sorted (control) spermatozoa were assessed after freeze-thawing. After sorting, semen from three rams (n = 3 ejaculates per ram) was diluted in four different extenders: ultra-heat-treated (UHT) long life milk, TRIS containing 10% (v/v) egg yolk (TRIS-EY), AH (pH 7.4), or TEST buffer containing 10% (v/v) egg yolk (TYB). Sorted and non-sorted (control) spermatozoa were stored at 15 degrees C for 24h or 5 degrees C for 6 days. Sperm characteristics were evaluated at 0, 6 and 24h for samples stored at 15 degrees C and daily for samples stored at 5 degrees C. The SMT was performed on sorted and non-sorted (control) spermatozoa after 6h and 3 days storage at 15 and 5 degrees C, respectively. Spermatozoa stored in TRIS were sorted more efficiently, had higher motility after sorting, freezing, thawing and incubation and had greater numbers of spermatozoa penetrating into the SMT than spermatozoa stored in AH prior to sorting. Spermatozoa stored in UHT at both temperatures had higher motility, acrosome integrity and traveled greater distances in the SMT than spermatozoa stored in all other diluents. In summary, storage in TRIS at 21 degrees C was optimal for transport of ram spermatozoa to the sorting site, and storage of spermatozoa in UHT diluent (after sorting) preserved sperm viability and migration ability best at both 15 and 5 degrees C.

Role of the hMLH1 DNA mismatch repair protein in fluoropyrimidine-mediated cell death and cell cycle responses

DNA mismatch repair (MMR) is an efficient system for the detection and repair of mismatched and unpaired bases in DNA. Deficiencies in MMR are commonly found in both hereditary and sporadic colorectal cancers, as well as in cancers of other tissues. Because fluorinated thymidine analogues (which through their actions might generate lesions recognizable by MMR) are widely used in the treatment of colorectal cancer, we investigated the role of MMR in cellular responses to 5-fluorouracil and 5-fluoro-2'-deoxyuridine (FdUrd). Human MLH1(-) and MMR-deficient HCT116 colon cancer cells were 18-fold more resistant to 7.5 microM 5-fluorouracil (continuous treatment) and 17-fold more resistant to 7.5 microM FdUrd in clonogenic survival assays compared with genetically matched, MLH1(+) and MMR-proficient HCT116 3-6 cells. Likewise, murine MLH1(-) and MMR-deficient CT-5 cells were 3-fold more resistant to a 2-h pulse of 10 microM FdUrd than their MLH1(+) and MMR-proficient ME-10 counterparts. Decreased cytotoxicity in MMR-deficient cells after treatment with various methylating agents and other base analogues has been well reported and is believed to reflect a tolerance to DNA damage. Synchronized HCT116 3-6 cells treated with a low dose of FdUrd had a 2-fold greater G(2) cell cycle arrest compared with MMR-deficient HCT116 cells, and asynchronous ME-10 cells demonstrated a 4-fold greater G(2) arrest after FdUrd treatment compared with CT-5 cells. Enhanced G(2) arrest in MMR-proficient cells in response to other agents has been reported and is believed to allow time for DNA repair. G(2) cell cycle arrest as determined by propidium iodide staining was not a result of mitotic arrest, but rather a true G(2) arrest, as indicated by elevated cyclin B1 levels and a lack of staining with mitotic protein monoclonal antibody 2. Additionally, p53 and GADD45 levels were induced in FdUrd-treated HCT116 3-6 cells. DNA double-strand break (DSB) formation was 2-fold higher in MMR-proficient HCT116 3-6 cells after FdUrd treatment, as determined by pulsed-field gel electrophoresis. The formation of DSBs was not the result of enhanced apoptosis in MMR-proficient cells. FdUrd-mediated cytotoxicity was caused by DNA-directed and not RNA-directed effects, because administration of excess thymidine (and not uridine) prevented cytotoxicity, cell cycle arrest, and DSB formation. hMLH1-dependent responses to fluoropyrimidine treatment, which may involve the action of p53 and the formation of DSBs, clearly have clinical relevance for the use of this class of drugs in the treatment of tumors with MMR deficiencies.

Tyrosine kinase inhibitors and signal transduction modulators: Rationale and current status as chemopreventive agents for prostate cancer

Cell growth and differentiation are processes intimately associated with carcinogenesis and regulated by tyrosine kinases and other signaling proteins. Identification of drugs that target signaling molecules is hampered by both the large number of targets and the complex nature of signaling cascades. Optimal development of chemopreventive agents must take into account affinity for the target, pharmacology, and safety profile of the agent. Validated biomarkers will allow the optimal implementation of chemopreventive trials. Directed epidemiologic studies can lead to the identification of lead compounds for chemoprevention, such as genistein. Therefore, agents targeted to pathways and molecules of known biological importance in the prostate hold the promise of clinical efficacy against prostate cancer in a chemopreventive setting.

Evaluation of CD8(+) T-cell frequencies by the Elispot assay in healthy individuals and in patients with metastatic melanoma immunized with tyrosinase peptide

The lack of reproducible, quantitative assays for T-cell responses has been a limitation in the development of cancer vaccines to elicit T-cell immunity. We utilized the Elispot assay, which allows a quantitative and functional assessment of T cells directed against specific peptides after only brief in vitro incubations. CD8(+) T-cell reactivity was determined with an interferon (IFN)-gamma Elispot assay detecting T cells at the single cell level that secrete IFN-gamma. We studied both healthy individuals and patients with melanoma. Healthy HLA-A*0201-positive individuals showed a similar mean frequency of CD8(+) cells recognizing a tyrosinase peptide, YMDGTMSQV, when compared with melanoma patients prior to immunization. The frequencies of CD8(+) cells recognizing the tyrosinase peptide remained relatively constant over time in healthy individuals. Nine HLA-A*0201-positive patients with stage IV metastatic melanoma were immunized intradermally with the tyrosinase peptide together with the immune adjuvant QS-21 in a peptide dose escalation study with 3 patients per dose group. Two patients demonstrated a significant increase in the frequency of CD8(+) cells recognizing the tyrosinase peptide during the course of immunization, from approx. 1/16,000 CD8(+) T cells to approx. 1/4,000 in the first patient and from approx. 1/14,000 to approx. 1/2,000 in the second patient. These results demonstrate that modest expansion of peptide-specific CD8(+) T cells can be generated in vivo by immunization with peptide plus QS-21 in at least a subset of patients with melanoma.

Induction of antibodies against GD3 ganglioside in melanoma patients by vaccination with GD3-lactone-KLH conjugate plus immunological adjuvant QS-21

The gangliosides GD3, GD2 and GM2 are expressed on the cell surface of malignant melanomas, GD3 being the most abundant. We have shown that immunization of melanoma patients with GM2 adherent to Bacillus Calmette-Guerin (GM2/BCG) induced an IgM antibody response. Vaccines containing GM2-keyhole limpet hemocyanin (KLH) conjugate and the immunological adjuvant QS-21 induced a higher titer IgM response and consistent IgG antibodies. Patients with antibodies against GM2 survived longer than patients without antibody. On the other hand, our previous trials with GD3/BCG, GD3 derivatives including GD3-lactone (GD3-L)/BCG failed to induce antibodies against GD3. In our continuing efforts to induce antibody against GD3, we have immunized groups of 6 melanoma patients with GD3-KLH or GD3-L-KLH conjugates containing 30 microg of ganglioside plus 100 microg of QS-21 at 0, 1, 2, 3, 7 and 19 weeks. Prior to vaccination, no serological reactivity against GD3 or GD3-L was detected. After immunization, IgM and IgG antibodies were detected against both GD3 and GD3-L in the GD3-L group exclusively. The GD3-L-KLH vaccine induced IgM titers against GD3-L of 1:40-1/1,280 in all patients and IgG titers of 1/160-1/1,280 in 4 patients. These antibodies also strongly cross-reacted with GD3. ELISA reactivity was confirmed by immune thin-layer chromatography on GD3 and melanoma extracts. Sera obtained from 4 of these 6 patients showed cell surface reactivity by FACS and from 2 showed strong cell surface reactivity by immune adherence (IA) assay and complement lysis against the GD3 positive cell line SK-Mel-28.

Phthalocyanine 4-photodynamic therapy induces ceramide generation and apoptosis in acid sphingomyelinase-deficient mouse embryonic fibroblasts

Photodynamic therapy (PDT), a novel cancer treatment using a photosensitizer and visible light, produces an oxidative stress in cells that can lead to apoptosis. PDT with the phthalocyanine photosensitizer Pc 4 (Pc 4-PDT), causes increased generation of ceramide, a lipid mediator, and subsequent induction of apoptosis in various cell types. Formation of ceramide by acid sphingomyelinase (ASMase) in response to stress has been implicated in apoptotic cell death. We assessed the role of ASMase in photocytotoxicity using mouse embryonic fibroblasts (MEFs) isolated from ASMase knockout (k/o) and wild-type (wt) mice. Exposure of wt or k/o MEFs to Pc 4-PDT led to increased caspase-3 activity and subsequent apoptosis. Similarly, ceramide levels were elevated in both cell types post-PDT. We suggest that in MEFs, ASMase is dispensable for ceramide accumulation and induction of apoptosis after Pc 4-PDT.

Epidemiology of glycopeptide-resistant enterococci colonizing high-risk patients in hospitals in Johannesburg, Republic of South Africa

Recent cases of infections caused by glycopeptide-resistant enterococci (GRE) have highlighted the emergence of these organisms in the Republic of South Africa. During May 1998 we conducted a prevalence study in four hospitals in Johannesburg and obtained 184 rectal swabs from patients identified as being at high risk for GRE colonization. Twenty enterococcal isolates showing various glycopeptide resistance genotypes were recovered: 3 Enterococcus faecium vanA isolates, 10 E. faecium vanB isolates, 6 E. gallinarum vanC1 isolates, and 1 E. avium vanA isolate. Macrorestriction analysis was used to demonstrate the clonal spread of GRE strains within hospitals. Evidence also demonstrated the likely persistence of the original E. faecium vanA isolate associated with the first confirmed death contributed to by GRE infection in South Africa in March 1997.

The mismatch repair protein, hMLH1, mediates 5-substituted halogenated thymidine analogue cytotoxicity, DNA incorporation, and radiosensitization in human colon cancer cells

Deficiency in DNA mismatch repair (MMR) is found in some hereditary (hereditary nonpolyposis colorectal cancer) and sporadic colon cancers as well as other common solid cancers. MMR deficiency has recently been shown to impart cellular resistance to multiple chemical agents, many of which are commonly used in cancer chemotherapy. It is therefore of interest to find an approach that selectively targets cells that have lost the ability to perform MMR. In this study, we examine the response of MMR-proficient (hMLH1+) and MMR-deficient (hMLH1-) colon carcinoma cell lines to the halogenated thymidine (dThd) analogues iododeoxyuridine (IdUrd) and bromodeoxyuridine (BrdUrd) before and after irradiation. These dThd analogues are used clinically as experimental sensitizing agents in radioresistant human cancers, and there is a direct correlation between the levels of dThd analogue DNA incorporation and tumor radiosensitization. In contrast to the well-characterized, marked increase in cytotoxicity (> 1 log cell kill) found with 6-thioguanine exposures in HCT116/3-6 (hMLH1+) cells compared to HCT116 (hMLH1-) cells, we found only modest cytotoxicity (10-20% cell kill) in both cell lines when treated with IdUrd or BrdUrd for 1 population doubling. Upon further analysis, the levels of halogenated dThd analogues in DNA were significantly lower (two to three times lower) in HCT116/3-6 cells than in HCT116 cells, and similar results were found in Mlh1+/+ spontaneously immortalized murine embryonic fibroblasts and fibroblasts from Mlh1 knockout mice. As a result of the higher levels of the dThd analogue in DNA, there was an increase in radiation sensitivity in HCT116 cells but not in HCT116/3-6 cells after pretreatment with IdUrd or BrdUrd when compared to treatment with radiation alone. Additionally, we found no differences in the cellular metabolic pathways for dThd analogue DNA incorporation because the enzyme activities of dThd kinase and thymidylate synthase, as well as the levels of triphosphate pools, were similar in HCT116 and HCT116/3-6 cells. These data suggest that the hMLH1 protein may participate in the recognition and subsequent removal of halogenated dThd analogues from DNA. Consequently, whereas MMR-deficient cells and tumor xenografts have shown intrinsic resistance to a large number of chemotherapeutic agents, the 5-halogenated dThd analogues appear to selectively target such cells for potential enhanced radiation sensitivity.

Immunization of melanoma patients with BEC2-keyhole limpet hemocyanin plus BCG intradermally followed by intravenous booster immunizations with BEC2 to induce anti-GD3 ganglioside antibodies

BEC2 is an anti-idiotypic mouse monoclonal antibody that mimics GD3 ganglioside. Previous clinical trials demonstrated that intradermal immunization using 2.5 mg of BEC2 with BCG or i.v. immunization with 10 mg of BEC2 can induce anti-GD3 antibodies in a subset of patients. We hypothesized that combining these two immunization strategies might be more effective in inducing anti-GD3 antibodies and that conjugation of BEC2 to keyhole limpet hemocyanin (KLH) would further enhance the immunogenicity of BEC2. In this clinical trial, 18 melanoma patients who were free of disease after complete surgical resection within 1-6 months received intradermal immunizations on weeks 0, 2, 4, 6, and 10 with 2.5 mg of BEC2 conjugated to KLH and mixed with BCG (BEC2-KLH/BCG). Booster immunizations of 10 mg of unconjugated BEC2 were administered i.v. on weeks 24, 37, and 50. Four of 18 patients (22%) developed IgM anti-GD3 antibodies. No IgG anti-GD3 antibodies were detected. All four responding patients developed anti-GD3 IgM during immunization with BEC2-KLH/BCG; only one patient demonstrated a reboost of the IgM anti-GD3 titer during the i.v. immunizations. Thirteen of the patients are free of melanoma (3 after undergoing re-resection for local relapse); 14 patients (78%) remain alive with a median follow-up of 28 months. These results confirm our previous trial, showing that BEC2 with BCG can induce anti-GD3 antibodies in patients. The data do not provide evidence that conjugation to KLH increases the immunogenicity of BEC2 when it is administered with BCG.

Defective expression of the DNA mismatch repair protein, MLH1, alters G2-M cell cycle checkpoint arrest following ionizing radiation

A role for the Mut L homologue-1 (MLH1) protein, a necessary component of DNA mismatch repair (MMR), in G2-M cell cycle checkpoint arrest after 6-thioguanine (6-TG) exposure was suggested previously. A potential role for MLH1 in G1 arrest and/or G1-S transition after damage was, however, not discounted. We report that MLH1-deficient human colon carcinoma (HCT116) cells showed decreased survival and a concomitant deficiency in G2-M cell cycle checkpoint arrest after ionizing radiation (IR) compared with genetically matched, MMR-corrected human colon carcinoma (HCT116 3-6) cells. Similar responses were noted between murine MLH1 knockout compared to wild-type primary embryonic fibroblasts. MMR-deficient HCT116 cells or embryonic fibroblasts from MLH1 knockout mice also demonstrated classic DNA damage tolerance responses after 6-TG exposure. Interestingly, an enhanced p53 protein induction response was observed in HCT116 3-6 (MLH1+) compared with HCT116 (MLH1-) cells after IR or 6-TG. Retroviral vector-mediated expression of the E6 protein did not, however, affect the enhanced G2-M cell cycle arrest observed in HCT116 3-6 compared with MLH1-deficient HCT116 cells. A role for MLH1 in G2-M cell cycle checkpoint control, without alteration in G1, after IR was also suggested by similar S-phase progression between irradiated MLH1-deficient and MLH1-proficient human or murine cells. Introduction of a nocodazole-induced G2-M block, which corrected the MLH1-mediated G2-M arrest deficiency in HCT116 cells, clearly demonstrated that HCT116 and HCT116 3-6 cells did not differ in G1 arrest or G1-S cell cycle transition after IR. Thus, our data indicate that MLH1 does not play a major role in G1 cell cycle transition or arrest. We also show that human MLH1 and MSH2 steady-state protein levels did not vary with damage or cell cycle changes caused by IR or 6-TG. MLH1-mediated G2-M cell cycle delay (caused by either MMR proofreading of DNA lesions or by a direct function of the MLH1 protein in cell cycle arrest) may be important for DNA damage detection and repair prior to chromosome segregation to eliminate carcinogenic lesions (possibly brought on by misrepair) in daughter cells.

Metastatic germ cell tumors: modeling for response to chemotherapy

PURPOSE

This study sought to determine factors that predict response to chemotherapy for patients with advanced germ cell tumors (GCTs), to evaluate different methods by which serum tumor markers can be used to predict response independent of assay method, and to develop criteria to guide allocation to clinical trials.

METHODS

Pretreatment data from 796 patients treated with platinum-based chemotherapy on Memorial Hospital protocols from 1975 to 1990 were analyzed. Multivariate analyses were performed on a developmental data set (n = 597) to assess for independently significant predictors of response. Predictive models developed using these methods were confirmed on the validation set (n = 199).

RESULTS

Independently significant factors for response included a mediastinal primary tumor (.015), pure seminomatous histology (.002), metastases to nonpulmonary visceral sites (bone, liver, and brain; .0001), and the pretreatment values of lactate dehydrogenase (LDH; .0001) and human chorionic gonadotropin (HCG; .0001). The likelihood of complete response (CR) was increased by seminomatous histology and decreased by the other factors. Serum levels of HCG and LDH could predict outcome independent of assay methodology. A model to predict good-, intermediate-, and poor-risk categories with CR rates of 92%, 76%, and 39%, respectively, was developed.

CONCLUSION

The independent prognostic factors of serum tumor markers LDH and HCG, the sites of metastases, and the primary origin of GCTs can predict outcome in patients with advanced GCT. These factors should be considered in the allocation of patients with advanced disease to clinical trials and have been included in the new tumor-node-metastasis (TNM) staging systems developed for the American Joint Committee on Cancer (AJCC) and the Union Internationale Contre le Cancer (UICC).

Chromosomal instability and its relationship to other end points of genomic instability

Chromosomal destabilization is one end point of the more general phenomenon of genomic instability. We previously established that chromosomal instability can manifest in clones derived from single progenitor cells several generations after X-irradiation. To understand the potential relationship between chromosomal destabilization and the other end points of genomic instability, we generated a series of chromosomally stable and unstable clones by exposure to X-rays. All clones were derived from the human-hamster hybrid line GM10115, which contains a single copy of human chromosome 4 in a background of 20-24 hamster chromosomes. These clones were then subjected to a series of assays to determine whether chromosomal instability is associated with a general "mutator phenotype" and whether it modulates other end points of genomic instability. Thus, we analyzed clones for sister chromatid exchange, delayed reproductive cell death, delayed mutation, mismatch repair, and delayed gene amplification. Statistical analyses performed on each group of chromosomally stable and unstable clones indicated that, although individual clones within each group were significantly different from unirradiated clones for many of the end points, there was no significant correlation between chromosomal instability and sister chromatid exchange, delayed mutation, and mismatch repair. Delayed gene amplification was found to be marginally correlated to chromosomal instability (P < 0.1), and delayed reproductive cell death (the persistent reduction in plating efficiency after irradiation) was found to be significantly correlated (P < 0.05). These correlations may be explained by chromosomal destabilization, which can mediate gene amplification and can result in cellular lethality. These data implicate multiple molecular and genetic pathways leading to different manifestations of genomic instability in GM10115 cells surviving exposure to DNA-damaging agents.