Prenatal BRCA1 epimutations contribute significantly to triple-negative breast cancer development

BACKGROUND

Normal cell BRCA1 epimutations have been associated with increased risk of triple-negative breast cancer (TNBC). However, the fraction of TNBCs that may have BRCA1 epimutations as their underlying cause is unknown. Neither are the time of occurrence and the potential inheritance patterns of BRCA1 epimutations established.

METHODS

To address these questions, we analyzed BRCA1 methylation status in breast cancer tissue and matched white blood cells (WBC) from 408 patients with 411 primary breast cancers, including 66 TNBCs, applying a highly sensitive sequencing assay, allowing allele-resolved methylation assessment. Furthermore, to assess the time of origin and the characteristics of normal cell BRCA1 methylation, we analyzed umbilical cord blood of 1260 newborn girls and 200 newborn boys. Finally, we assessed BRCA1 methylation status among 575 mothers and 531 fathers of girls with (n = 102) and without (n = 473) BRCA1 methylation.

RESULTS

We found concordant tumor and mosaic WBC BRCA1 epimutations in 10 out of 66 patients with TNBC and in four out of six patients with estrogen receptor (ER)-low expression (< 10%) tumors (combined: 14 out of 72; 19.4%; 95% CI 11.1-30.5). In contrast, we found concordant WBC and tumor methylation in only three out of 220 patients with 221 ER ≥ 10% tumors and zero out of 114 patients with 116 HER2-positive tumors. Intraindividually, BRCA1 epimutations affected the same allele in normal and tumor cells. Assessing BRCA1 methylation in umbilical WBCs from girls, we found mosaic, predominantly monoallelic BRCA1 epimutations, with qualitative features similar to those in adults, in 113/1260 (9.0%) of individuals, but no correlation to BRCA1 methylation status either in mothers or fathers. A significantly lower fraction of newborn boys carried BRCA1 methylation (9/200; 4.5%) as compared to girls (p = 0.038). Similarly, WBC BRCA1 methylation was found less common among fathers (16/531; 3.0%), as compared to mothers (46/575; 8.0%; p = 0.0003).

CONCLUSIONS

Our findings suggest prenatal BRCA1 epimutations might be the underlying cause of around 20% of TNBC and low-ER expression breast cancers. Such constitutional mosaic BRCA1 methylation likely arise through gender-related mechanisms in utero, independent of Mendelian inheritance.

Comparison of humans versus mobile phone-powered artificial intelligence for the diagnosis and management of pigmented skin cancer in secondary care: a multicentre, prospective, diagnostic, clinical trial

BACKGROUND

Diagnosis of skin cancer requires medical expertise, which is scarce. Mobile phone-powered artificial intelligence (AI) could aid diagnosis, but it is unclear how this technology performs in a clinical scenario. Our primary aim was to test in the clinic whether there was equivalence between AI algorithms and clinicians for the diagnosis and management of pigmented skin lesions.

METHODS

In this multicentre, prospective, diagnostic, clinical trial, we included specialist and novice clinicians and patients from two tertiary referral centres in Australia and Austria. Specialists had a specialist medical qualification related to diagnosing and managing pigmented skin lesions, whereas novices were dermatology junior doctors or registrars in trainee positions who had experience in examining and managing these lesions. Eligible patients were aged 18-99 years and had a modified Fitzpatrick I-III skin type; those in the diagnostic trial were undergoing routine excision or biopsy of one or more suspicious pigmented skin lesions bigger than 3 mm in the longest diameter, and those in the management trial had baseline total-body photographs taken within 1-4 years. We used two mobile phone-powered AI instruments incorporating a simple optical attachment: a new 7-class AI algorithm and the International Skin Imaging Collaboration (ISIC) AI algorithm, which was previously tested in a large online reader study. The reference standard for excised lesions in the diagnostic trial was histopathological examination; in the management trial, the reference standard was a descending hierarchy based on histopathological examination, comparison of baseline total-body photographs, digital monitoring, and telediagnosis. The main outcome of this study was to compare the accuracy of expert and novice diagnostic and management decisions with the two AI instruments. Possible decisions in the management trial were dismissal, biopsy, or 3-month monitoring. Decisions to monitor were considered equivalent to dismissal (scenario A) or biopsy of malignant lesions (scenario B). The trial was registered at the Australian New Zealand Clinical Trials Registry ACTRN12620000695909 (Universal trial number U1111-1251-8995).

FINDINGS

The diagnostic study included 172 suspicious pigmented lesions (84 malignant) from 124 patients and the management study included 5696 pigmented lesions (18 malignant) from the whole body of 66 high-risk patients. The diagnoses of the 7-class AI algorithm were equivalent to the specialists' diagnoses (absolute accuracy difference 1·2% [95% CI -6·9 to 9·2]) and significantly superior to the novices' ones (21·5% [13·1 to 30·0]). The diagnoses of the ISIC AI algorithm were significantly inferior to the specialists' diagnoses (-11·6% [-20·3 to -3·0]) but significantly superior to the novices' ones (8·7% [-0·5 to 18·0]). The best 7-class management AI was significantly inferior to specialists' management (absolute accuracy difference in correct management decision -0·5% [95% CI -0·7 to -0·2] in scenario A and -0·4% [-0·8 to -0·05] in scenario B). Compared with the novices' management, the 7-class management AI was significantly inferior (-0·4% [-0·6 to -0·2]) in scenario A but significantly superior (0·4% [0·0 to 0·9]) in scenario B.

INTERPRETATION

The mobile phone-powered AI technology is simple, practical, and accurate for the diagnosis of suspicious pigmented skin cancer in patients presenting to a specialist setting, although its usage for management decisions requires more careful execution. An AI algorithm that was superior in experimental studies was significantly inferior to specialists in a real-world scenario, suggesting that caution is needed when extrapolating results of experimental studies to clinical practice.

FUNDING

MetaOptima Technology.

Abstract OT2-19-01: Single cell characterization of longitudinal biopsies from breast cancer patients treated neoadjuvantly with the aromatase inhibitor letrozole and the CDK4/6 inhibitor ribociclib in concert

Background The recent introduction of CDK4/6 inhibitors has been one of the most pivotal breakthroughs in breast cancer therapy during the last decades. A growing body of evidence proposes that CDK4/6 inhibitors influence the recruitment of immune cells in the tumor microenvironment with potential effects on the outcome. Study design The NeoLetRib-study is a multicenter, single-arm, open-label, neoadjuvant, phase II trial aiming at treating 100 locally advanced luminal-A and luminal-B breast cancer patients, defined as either large T2, or T3/T4, and/or N2-3. Patients receive neoadjuvant therapy for 6 months: ribociclib (600 mg daily, 21 days on/7 days off) and letrozole (2.5 mg daily). Peri- and premenopausal women also receive therapy with goserelin 3.6 mg s.c every 28 days. Methods Three sequencial tumor biopsies were collected: pre-treatment and on-treatment (cycle 1 - day 21 and cycle 6 - day 21 with ribociclib). These biopsies were subjected to single-cell transcriptome, T cell receptor and B cell receptor profiling using the Chromium Single-Cell v2 5′ Chemistry (10x Genomics). Libraries were paired-end sequenced on a NovaSeq6000. Single cell gene expression matrices were analyzed with the Seurat package (v4.0.2). After filtering out stressed/dying cells or cells with low quality sequencing, gene expression of the remaining good quality cells was normalized and scaled to construct principal components and further cluster cells. Results In this planned interim analysis, we clustered 242315 cells from longitudinal tumor biopsies from 18 patients at pre-treatment, 18 at cycle 1 - day 21 and 9 at cycle 6 - day 21, respectively. We identified 8 main cell types: T cells, B cells, epithelial cells, fibroblasts, endothelial cells, macrophages, mast cells and dendritic cells. To further identify specific and specialized cell subtypes, we clustered the cells belonging to the above-mentioned cell types and annotated the clusters obtained using validated marker genes. Statistical methods and algorithms were then used to characterize how the proportion of different cell types changes in tumors under treatment pressure. We identified significant changes in immune cell proportions, including regulatory T cells, CD14 monocytes, SLC2A1-Macrophages among others. Conclusions In this unique patient cohort, we used single cell transcriptome profiling to obtain a high-resolution map of cell types found in tumor biopsies from the NeoLetRib trial. We characterized the effects of the combination of ribociclib and letrozole on the tumor microenvironment and identified cells sensitive and resistant to treatment. In this interim analysis, the observed longitudinal changes of immune cell types proportions in the tumor microenvironment might suggest immune related effects of the treatment combination.

Citation Format: Marie Fongård, Chloé Steen, Salim Ghannoum, Marius Bjørnstad, Barbro Holm, Tatjana Bosnjak, Laurens Reitsma, Stephanie Geisler, Kamilla Fjermeros, Johannes Bruteig, Manouchehr Seyedzadeh, Unn-Cathrin Buvarp, Marie Loeng, Aino Vuoriluoto, Torben Lüders, Diether Lambrechts, Marianne Lyngra, Vessela Kristensen, Jürgen Geisler, Xavier Tekpli. Single cell characterization of longitudinal biopsies from breast cancer patients treated neoadjuvantly with the aromatase inhibitor letrozole and the CDK4/6 inhibitor ribociclib in concert [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT2-19-01.

Abstract PD10-10: PD10-10 Single cell characterization of longitudinal biopsies from breast cancer patients treated with the aromatase inhibitors letrozole and exemestane in sequence

Background About 70% of breast cancer cases are hormone receptor positive, indicating that cancer cells exploit estrogens for their growth. Postmenopausal estrogen receptor positive breast cancer patients are currently often treated with aromatase inhibitors suppressing serum and tumor tissue estradiol levels by &gt;90%. Two widely used aromatase inhibitors are letrozole, a nonsteroidal inhibitor and exemestane, a steroidal aromatase inactivator. While the mechanisms of action of these two drugs are well studied, their effects on the tumor immune microenvironment and mechanisms of resistance to these drugs are still not sufficiently elucidated. Study design The NEOLETEXE trial1 was a neoadjuvant, randomized, open-label, intra-patient, cross-over, single center clinical trial aiming at treating postmenopausal patients with locally advanced breast cancer defined primarily as large T3/T4 and or N2/N3. However, patients with large T2 tumors were also eligible. Patients were randomized to neoadjuvant therapy with either letrozole (2.5 mg daily) or exemestane 25 mg daily for about 3 months, followed by a cross-over to the alternative drug for another 3 months prior to surgery. 102 patients were enrolled in NEOLETEXE. Methods Pre-treatment, on-treatment (3 months) and end-of-treatment (6 months of therapy) biopsies were subjected to single-cell transcriptome, T cell receptor and B cell receptor profiling using the Chromium Single-Cell v2 5′ Chemistry (10x Genomics). Libraries were paired-end sequenced on a NovaSeq6000. Single cell gene expression matrices were analyzed with the Seurat package (v4.0.2). After filtering out stressed/dying cells or cells with low quality sequencing, gene expression of the remaining good quality cells was normalized and scaled to construct principal components and further cluster cells. Results We clustered 362.762 cells from 26 pre-treatment, 20 on-treatment and 19 end-of-treatment biopsies and identified 8 main cell types to be present: T cells, B cells, epithelial cells, fibroblasts, endothelial cells, macrophages, mast cells and dendritic cells. To further identify specific and specialized cell subtypes, we clustered the cells belonging to the above-mentioned cell types independently and annotated the clusters obtained using validated marker genes. Finally, we use statistical methods and algorithms to characterize how the proportion of the different cell types changes in tumors under treatment pressure. Specifically, we show changes in the proportion of CD8 effector memory cells under treatment pressure, with a significant increase in cytotoxic T cell proportions after two months of treatment with aromatase inhibitor. Conclusions We use single cell profiling to obtain a high-resolution map of the cell types found in tumor biopsies of the NEOLETEXE trial to characterize the effects of aromatase inhibitors on the tumor microenvironment and to identify the cancer cell signatures during treatment with letrozole or exemestane. 1. Bahrami N., Sauer T., Engebretsen S., Aljabri B., Bemanian V.,Lindstrøm J., Lüders T., Kristensen V.N., Lorentzen A., Loeng M., Ødegård H.P., Kvaløy J.Ø., Vestøl I.B., Geisler S.B., Gravdehaug B., Gundersen J.M., Geisler J. The NEOLETEXE trial: a neoadjuvant cross-over study exploring the lack of cross resistance between aromatase inhibitors. Future Oncology, 15 (32), 3675-3682, 2019.

Citation Format: Salim Ghannoum, Chloé Steen, Marie Fongård, Marius Bjørnstad, Laurens Reitsma, Stephanie Geisler, Manouchehr Seyedzadeh, Unn-Cathrin Buvarp, Marie Loeng, Torben Lüders, Diether Lambrechts, Marianne Lyngra, Vessela Kristensen, Jürgen Geisler, Xavier Tekpli. PD10-10 Single cell characterization of longitudinal biopsies from breast cancer patients treated with the aromatase inhibitors letrozole and exemestane in sequence [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD10-10.

Repetitive transcranial magnetic stimulation in the treatment of resistant depression: changes of specific neurotransmitter precursor amino acids

Repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant major depression offers an alternative therapy, since more than every third patient is not responding to adequate antidepressive treatment. In this interventional study safety, symptom development and changes of serum concentrations of neurotransmitter precursor amino acids, of immune activation and inflammation markers, of brain-derived neurotrophic factor (BDNF), nitrite as well as of salivary amylase were measured before and after a frontal polar cortex stimulation using rTMS as add-on treatment in 38 patients with treatment-resistant depression. Out of these, 17 patients received sham stimulation as a control. Treatment was well tolerated: with the exception of one patient of the verum group, who described discomfort during the second treatment, no serious adverse effects were observed. Improvement of depression with a significant decrease in the HAMD-7 scale (p = 0.001) was found in patients treated with rTMS, but not in sham-treated patients. Furthermore, serum phenylalanine and tyrosine dropped significantly (p = 0.03 and p = 0.027, respectively) in rTMS-treated patients. The kynurenine to tryptophan ratio (Kyn/Trp) tended to decrease under rTMS (p = 0.07). In addition, associations between concentrations of BDNF and neopterin as well as serum nitrite levels were found in patients after rTMS treatment, which indicates an influence of immune regulatory circuits on BDNF levels. In the sham-treated patients, no changes of biomarker concentrations were observed. Results show that rTMS is effective in the treatment of resistant depression. rTMS appears to influence the enzyme phenylalanine hydroxylase, which plays a central role in the biosynthesis of neurotransmitter precursors tyrosine and dihydroxyphenylalanine (DOPA).

The Iliofemoral tortuosity score predicts access and bleeding complications during transfemoral transcatheter aortic valve replacement: DataData from the VIenna Cardio Thoracic aOrtic valve registrY (VICTORY)

BACKGROUND

Arterial tortuosity is linked to a higher risk of adverse clinical events after transfemoral transcatheter aortic valve replacement (TF-TAVR). Currently, there are no assessment tools that can quantify this variable in three-dimensional space. This study investigated the impact of novel scoring methods of iliofemoral tortuosity on access and bleeding complications after TF-TAVR.

METHODS

The main access vessel was assessed between the aortoiliacal and femoral bifurcation in preoperative multislice computed tomography scans of 240 consecutive patients undergoing TF-TAVR. Tortuosity was assessed by three methods: largest single angle, sum of all angles, and iliofemoral tortuosity (IFT) score [((true vessel length/ideal vessel length)-1)*100]. The primary study endpoint was a composite of access and bleeding complications. The secondary study endpoints were 30-day mortality and long-term survival.

RESULTS

Among 240 patients, only the IFT score demonstrated a good positive correlation with the composite primary endpoint of access and bleeding complications (P = 0.031). A higher incidence of access and bleeding complications was found in patients with a higher IFT score (56 [36.8%] vs 17 [19.3%]; P = 0.003). In a multivariate logistic regression analysis, only the IFT score was a significant predictor of the primary endpoint (OR: 2.11; 95% CI: 1.09-4.05; P = 0.026).

CONCLUSION

Vascular tortuosity is an underestimated risk factor during TF-TAVR. The IFT score is a valuable tool in risk stratification before TF-TAVR, predicting periprocedural access and bleeding complications.

Clozapine administration in clinical practice: once-daily versus divided dosing

OBJECTIVE

While it is recommended that clozapine be administered in a divided dosing regimen, it is unclear whether this recommendation is followed in real-world clinical practice. In two large datasets, we examined clozapine dosing frequency and patient characteristics across different dosing regimens.

METHOD

We conducted a cross-sectional survey, collecting data on patients receiving clozapine in August/September 2015 from the Centre for Addiction and Mental Health (CAMH) in Toronto, Canada, and The Zucker Hillside Hospital (ZHH) in New York, United States.

RESULTS

Of 676 and 308 patients included in CAMH and ZHH datasets, clozapine was prescribed once daily in 75.1% and 74.4%, even though doses exceeding 200 mg/day were administered in 88.6% and 84.4% of the respective samples. No significant difference was found in the rates of positive symptom remission between once-daily vs. divided dosing (79.7% vs. 80.5%, P = 1.00). Higher clozapine dose and use of anticholinergic medications were significantly associated with divided dosing in both datasets. Older age or male gender was related to divided dosing in CAMH or ZHH dataset respectively.

CONCLUSION

Despite the product monograph recommendation, clozapine is frequently prescribed once daily in North America. Further studies are needed to compare clinical outcomes between once-daily vs. divided clozapine dosing.

Levels in neurotransmitter precursor amino acids correlate with mental health in patients with breast cancer

Breast cancer is the most common cancer among females. Approximately 30% of cancer patients develop depression or depressive adaptation disorder within 5 years post diagnosis. Low grade inflammation and subsequent changes in neurotransmitter levels could be the pathophysiological link. In the current study we investigated the association of neurotransmitter precursor amino acids with a diagnosis of depression or state anxiety in 154 subjects suffering from breast cancer (BCA(+)), depression (DPR(+)), both or neither. Sociodemographic parameters, severity of depressive symptoms, and state anxiety (ANX) were recorded. Neopterin, kynurenine/tryptophan and phenylalanine/tyrosine were analysed by HPLC or ELISA. Significantly higher serum neopterin values were found in DPR(+) patients (p = 0.034) and in ANX(+) subjects (p = 0.008), as a marker of Th1-related inflammation. The phenylalanine/tyrosine ratio (index of the catecholamine pathway) was associated with the factors "breast cancer" and "depression" and their interaction (all p < 0.001); it was highest in the DPR(+)BCA(+) group. The kynurenine/tryptophan ratio (index of the serotonin pathway) was significantly associated with the factors "breast cancer" and "state anxiety" and their interaction (p < 0.001, p = 0.026, p = 0.02, respectively); it was highest in the ANX(+)BCA(+) group. In BCA(+) patients kynurenine/tryptophan ratios correlated with severity of state anxiety (r = 0.226, p = 0.048, uncorrected) and phenylalanine/tyrosine ratios with severity of depressive symptoms (r = 0.376, p < 0.05, corrected). In conclusion, levels of neurotransmitter precursor amino acids correlate with mental health, an effect which was much more pronounced in BCA(+) patients than in BCA(-) subjects. Aside from identifying underlying pathophysiological mechanisms, these results could be the basis for future treatment studies: in BCA(+) patients with depression the use of serotonin-noradrenaline reuptake inhibitors might be recommended while in those with predominant anxiety selective serotonin reuptake inhibitors might be the treatment of choice.

Concomitant inactivation of the p53- and pRB- functional pathways predicts resistance to DNA damaging drugs in breast cancer in vivo

Chemoresistance is the main obstacle to cancer cure. Contrasting studies focusing on single gene mutations, we hypothesize chemoresistance to be due to inactivation of key pathways affecting cellular mechanisms such as apoptosis, senescence, or DNA repair. In support of this hypothesis, we have previously shown inactivation of either TP53 or its key activators CHK2 and ATM to predict resistance to DNA damaging drugs in breast cancer better than TP53 mutations alone. Further, we hypothesized that redundant pathway(s) may compensate for loss of p53‐pathway signaling and that these are inactivated as well in resistant tumour cells. Here, we assessed genetic alterations of the retinoblastoma gene (RB1) and its key regulators: Cyclin D and E as well as their inhibitors p16 and p27. In an exploratory cohort of 69 patients selected from two prospective studies treated with either doxorubicin monotherapy or 5‐FU and mitomycin for locally advanced breast cancers, we found defects in the pRB‐pathway to be associated with therapy resistance (p‐values ranging from 0.001 to 0.094, depending on the cut‐off value applied to p27 expression levels). Although statistically weaker, we observed confirmatory associations in a validation cohort from another prospective study (n = 107 patients treated with neoadjuvant epirubicin monotherapy; p‐values ranging from 7.0 × 10−4 to 0.001 in the combined data sets). Importantly, inactivation of the p53‐and the pRB‐pathways in concert predicted resistance to therapy more strongly than each of the two pathways assessed individually (exploratory cohort: p‐values ranging from 3.9 × 10−6 to 7.5 × 10−3 depending on cut‐off values applied to ATM and p27 mRNA expression levels). Again, similar findings were confirmed in the validation cohort, with p‐values ranging from 6.0 × 10−7 to 6.5 × 10−5 in the combined data sets. Our findings strongly indicate that concomitant inactivation of the p53‐ and pRB‐ pathways predict resistance towards anthracyclines and mitomycin in breast cancer in vivo.

Alterations of pRB's upstream regulators may substitute for RB1 mutations.

The pRB‐pathway may direct response to chemotherapy.

Inactivation of the p53‐and the pRB‐pathways predict resistance to chemotherapy.

Concomitant p53‐and pRB‐pathway inactivation is a strong resistance predictor.

Concomitant p53‐and pRB‐pathway inactivation predicts poor prognosis.

[Renal masses and indication to nephrectomy: preoperative assessment and clinical presentation of five cases]

In Switzerland, renal cancer represents 2% of adult neoplasia and its incidence is 8,2 cases per 100000 people. Small renal masses (< 4 cm) are mostly found incidentally during ultrasound or CT-scan evaluations. Differentiation between benign lesions (20% of renal masses < 4 cm), cancer and pseudotumors may be difficult. CT-scan plays a central role in the preoperative assessment, but the use of renal biopsy seems to have a growing importance in this assessment. This article summarizes the different diagnostic approaches in the preoperative assessment and describes five cases of nephrectomy for renal masses incidentally discovered.

Training alters the skeletal muscle antioxidative capacity in non-insulin-dependent type 2 diabetic men

The present study analyzes the oxidative stress situation in the skeletal muscle of overweight/obese men suffering from non-insulin-dependent type 2 diabetes mellitus [T2DM, n=16, years=61±7, body mass index (BMI)=31±4 kg/m(2) ] and BMI-matched non-diabetic male control subjects (CON, n=7, years=53±6, BMI=30±4 kg/m(2) ). Furthermore, it investigates whether physical training can alter the skeletal muscle antioxidative capacity of T2DM patients at rest. Molecule content analyses (immunohistochemical stainings) of 8-iso-prostaglandin-F2α (8-Iso-PGF), superoxide dismutase-2 (SOD2), glutathione peroxidase-1 (GPX1), peroxiredoxin isoforms (PRDX 1-6) and heat-shock-protein-70 (HSP70) were performed in biopsies taken from the vastus lateralis muscle. Under basal conditions, 8-Iso-PGF was significantly decreased in T2DM patients (-35.7%), whereas PRDX2 and PRDX6 were significantly increased relative to CON (+82.6%; +82.3%). Differences were neither observed in SOD2 nor in GPX1 or PRDX1, 3, 4, 5 density. Regular physical activity (moderate endurance or resistance training twice a week for 3 months) did not alter PRDX1, 2, 3, 4, 6 in the skeletal muscle of T2DM patients, but significantly increased SOD2 (+65.9%), GPX1 (+62.4%), PRDX5 (+37.5%), and HSP70 (+48.5%). Overweight/obese men with non-insulin-dependent T2DM exhibit up-regulated cytosolic peroxiredoxin contents relative to BMI-matched controls. Regular training further up-regulates cytosolic and mitochondrial antioxidative enzymes in T2DM patients and improves their cellular protection systems. This may contribute to a retardation of the disease's progression.

MSTN mRNA after varying exercise modalities in humans

The aim of this study was to examine the effects of strength and endurance training on myostatin mRNA in the vastus lateralis muscle of healthy and physically active humans. 21 healthy and physically active sports students (static and dynamic knee extensor strength 33 ± 4.5 N/kgBW; 1 185 ± 170 W, respectively; maximum oxygen uptake 52.5 ± 8 ml/kgBW/min) were recruited and randomly assigned to a moderate endurance training group (n=7), a strength training group (n=7) and a control group (n=7). Muscle biopsies were taken from the vastus lateralis muscle 3-5 days before the start as well as at the end of the 12 weeks' training period. Exercise-specific functional improvements after moderate endurance training and strength training were measured for submaximal endurance and for static and dynamic strength of the knee extensor muscles. None of the myostatin mRNA values showed significant pre-post differences or group-specific differences. These results are in contrast to data with sedentary subjects, suggesting that myostatin is necessary for adaptations of skeletal muscle to exercise stress. We conclude that functional improvements after moderate endurance training and strength training can occur without alterations in myostatin mRNA in physically active humans.

Identification and characterization of retinoblastoma gene mutations disturbing apoptosis in human breast cancers

Background

The tumor suppressor pRb plays a key role regulating cell cycle arrest, and disturbances in the RB1 gene have been reported in different cancer forms. However, the literature reports contradictory findings with respect to a pro - versus anti - apoptotic role of pRb, and the consequence of alterations in RB1 to chemotherapy sensitivity remains unclear. This study is part of a project investigating alterations in pivotal genes as predictive factors to chemotherapy sensitivity in breast cancer.

Results

Analyzing 73 locally advanced (stage III) breast cancers, we identified two somatic and one germline single nucleotide changes, each leading to amino acid substitution in the pRb protein (Leu607Ile, Arg698Trp, and Arg621Cys, respectively). This is the first study reporting point mutations affecting RB1 in breast cancer tissue. In addition, MLPA analysis revealed two large multiexon deletions (exons 13 to 27 and exons 21 to 23) with the exons 21-23 deletion occurring in the tumor also harboring the Leu607Ile mutation. Interestingly, Leu607Ile and Arg621Cys point mutations both localize to the spacer region of the pRb protein, a region previously shown to harbor somatic and germline mutations. Multiple sequence alignment across species indicates the spacer to be evolutionary conserved. All three RB1 point mutations encoded nuclear proteins with impaired ability to induce apoptosis compared to wild-type pRb in vitro. Notably, three out of four tumors harboring RB1 mutations displayed primary resistance to treatment with either 5-FU/mitomycin or doxorubicin while only 14 out of 64 tumors without mutations were resistant (p = 0.046).

Conclusions

Although rare, our findings suggest RB1 mutations to be of pathological importance potentially affecting sensitivity to mitomycin/anthracycline treatment in breast cancer.

Abstract 1092: Alterations of the retinoblastoma gene in stage III breast cancers

We report the novel finding of point mutations affecting the RB1 gene in breast cancer tissue. Analyzing 73 locally advanced (stage III) breast cancers, we identified two somatic and one germline single nucleotide changes, each leading to amino acid substitution; Leu607Ile, Arg698Trp, and Arg621Cys, respectively. In addition, MLPA analysis revealed two large multiexon deletions (exons 13 to 27 and exons 21 to 23) with the exons 21-23 deletion occurring in the tumor also harboring Leu607Ile. All three RB1 point mutations encoded stable nuclear proteins with impaired ability to induce apoptosis compared to wild-type pRb in vitro. Interestingly, Leu607Ile and Arg621Cys are both located within the spacer region of the protein. Mutations in this part of the RB1 gene have previously been identified in retinoblastoma-prone families. Multiple sequence alignment across species indicates this area to be evolutionary conserved. Notably, three out of four tumors harboring RB1 mutations displayed primary resistance to treatment with either mitomycin or doxorubicin while only 14 out of 64 tumors without mutations were resistant (p = 0.046). Although rare, our findings suggest RB1 mutations to be of biological importance in breast cancer.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1092.

Glutamatergic axons from the lateral habenula mainly terminate on GABAergic neurons of the ventral midbrain

The concept of cortical-subcortical loops emphasizes the importance of the basal ganglia for motor, psychomotor, and emotional cortical functions. These loops are bidirectionally controlled by the midbrain dopaminergic system, predominantly but not exclusively at the level of the striatum including the accumbens nucleus. Successful behaviors increase the activities of the mesostriatal (arising in the complex part of the substantia nigra) and mesolimbic (arising in the ventral tegmental area, VTA) neurons, thereby reinforcing the corresponding actions. In contrast, unsuccessful behaviors result in an increased activation of the lateral habenular complex (LHb), thereby decreasing the activities of mesolimbic neurons. Correspondingly, electrical stimulation of the LHb effectively blocks neuronal activity in the VTA. Whether this block is due to an inhibitory projection from the LHb to the VTA, or whether axons from excitatory LHb neurons target inhibitory neurons within the VTA, is presently not known. Here we show, using in situ hybridization and immunocytochemical double labeling at the light and electron microscopic level, that GABAergic neurons are scarce in the LHb and that glutamatergic axons from the LHb mostly target GABAergic neurons in the VTA and the mesopontine rostromedial tegmental nucleus (RMTg), also known as tail of the VTA (tVTA). These data explain the inhibitory effect of LHb activation on the VTA. In addition, however, a small number of LHb terminals in the VTA actually contacts dopaminergic neurons. The biological importance of these terminals requires further investigation.

DNA methylation profiling in doxorubicin treated primary locally advanced breast tumours identifies novel genes associated with survival and treatment response

Background

Breast cancer is the most frequent cancer in women and consists of a heterogeneous collection of diseases with distinct histopathological, genetic and epigenetic characteristics. In this study, we aimed to identify DNA methylation based biomarkers to distinguish patients with locally advanced breast cancer who may benefit from neoadjuvant doxorubicin treatment.

Results

We investigated quantitatively the methylation patterns in the promoter regions of 14 genes (ABCB1, ATM, BRCA1, CDH3, CDKN2A, CXCR4, ESR1, FBXW7, FOXC1, GSTP1, IGF2, HMLH1, PPP2R2B, and PTEN) in 75 well-described pre-treatment samples from locally advanced breast cancer and correlated the results to the available clinical and molecular parameters. Six normal breast tissues were used as controls and 163 unselected breast cancer cases were used to validate associations with histopathological and clinical parameters.

Aberrant methylation was detected in 9 out of the 14 genes including the discovery of methylation at the FOXC1 promoter. Absence of methylation at the ABCB1 promoter correlated with progressive disease during doxorubicin treatment. Most importantly, the DNA methylation status at the promoters of GSTP1, FOXC1 and ABCB1 correlated with survival, whereby the combination of methylated genes improved the subdivision with respect to the survival of the patients. In multivariate analysis GSTP1 and FOXC1 methylation status proved to be independent prognostic markers associated with survival.

Conclusions

Quantitative DNA methylation profiling is a powerful tool to identify molecular changes associated with specific phenotypes. Methylation at the ABCB1 or GSTP1 promoter improved overall survival probably due to prolonged availability and activity of the drug in the cell while FOXC1 methylation might be a protective factor against tumour invasiveness. FOXC1 proved to be general prognostic factor, while ABCB1 and GSTP1 might be predictive factors for the response to and efficacy of doxorubicin treatment. Pharmacoepigenetic effects such as the reported associations in this study provide molecular explanations for differential responses to chemotherapy and it might prove valuable to take the methylation status of selected genes into account for patient management and treatment decisions.

The murine Dnali1 gene encodes a flagellar protein that interacts with the cytoplasmic dynein heavy chain 1

Axonemal dyneins are large motor protein complexes generating the force for the movement of eukaryotic cilia and flagella. Disruption of axonemal dynein function leads to loss of ciliary motility and can result in male infertility or lateralization defects. Here, we report the molecular analysis of a murine gene encoding the dynein axonemal light intermediate chain Dnali1. The Dnali1 gene is localized on chromosome 4 and consists of six exons. It is predominantly expressed within the testis but at a lower level Dnali1 transcripts were also observed in different murine tissues, which exhibit cilia. Two transcript variants were detected, generated by the usage of two alternative polyadenylation signals within exon 6. Antibodies were raised against a GST-Dnali1 fusion protein and used to localize Dnali1 within differentiating male germ cells. Dnali1 is strongly expressed in spermatids but was also detected in spermatocytes. Moreover, the Dnali1 protein was localized in cilia of the trachea as well as in flagella of mature sperm supporting its function as an axonemal dynein. To identify putative Dnali1 interacting polypeptides, a yeast two-hybrid approach was performed using a murine testicular cDNA library. By this assay, the C-terminal part of the cytoplasmic dynein heavy chain 1 was identified as a putative interacting polypeptide of Dnali1. The interaction between the axonemal and the cytoplasmic dynein fragments was proven by co-immuno and co-localization experiments.

ABCB1 and GST polymorphisms associated with TP53 status in breast cancer

BACKGROUND AND OBJECTIVE

Many environmental and genetic factors influence the development of chemoresistance. The goal of this study was to characterize the genetic variation in the ABCB1, GSTM1, GSTT1 and GSTP1 genes, as well as the haplotype structure in the ABCB1 gene.

METHODS

Variants in these genes were studied in 109 healthy controls and 93 breast cancer cases, both of Caucasian origin. The cases were analyzed in relation to TP53 mutation status and response to doxorubicin. Both single and multiple single nucleotide polymorphism analyses were performed.

RESULTS

Chi-square analyses revealed a significant association between TP53 mutation status and both the GA genotype of ABCB1 exon 11 (Ser400Asn) and the GG genotype of GSTP1 (Ile105Val; P<0.01 and P<0.05, respectively). Multifactor dimensionality reduction showed that carriers of the combined GG genotype for GSTP1 and the GG for ABCB1 exon 11 had the highest chance of acquiring a mutation in the TP53 gene (P<0.02). Haplotype analysis of ABCB1 revealed a significantly different distribution of haplotypes between the breast cancer cases and the controls (P<0.01). A specific haplotype association to TP53 mutation (P<0.01) distant metastases (P<0.05) and estrogen receptor status (P<0.05) was also observed in the case group.

CONCLUSION

An association between polymorphisms in GSTP1 and ABCB1 and risk of acquiring intratumoral TP53 mutations suggests the existence of putative predisposing genotype backgrounds. The degree of linkage disequilibrium in the ABCB1 gene was higher in healthy individuals, whereas haplotypes in the cases seemed degenerated by a number of low frequency variants. This observation may either point to the existence of a protective haplotype in the controls or may underline the importance of the accumulation of low frequency variants as susceptibility factors.

Gene expression profiles do not consistently predict the clinical treatment response in locally advanced breast cancer

Neoadjuvant treatment offers an opportunity to correlate molecular variables to treatment response and to explore mechanisms of drug resistance in vivo. Here, we present a statistical analysis of large-scale gene expression patterns and their relationship to response following neoadjuvant chemotherapy in locally advanced breast cancers. We analyzed cDNA expression data from 81 tumors from two patient series, one treated with doxorubicin alone (51) and the other treated with 5-fluorouracil and mitomycin (30), and both were previously studied for correlations between TP53 status and response to therapy. We observed a low frequency of progressive disease within the luminal A subtype from both series (2 of 36 versus 13 of 45 patients; P = 0.0089) and a high frequency of progressive disease among patients with luminal B type tumors treated with doxorubicin (5 of 8 patients; P = 0.0078); however, aside from these two observations, no other consistent associations between response to chemotherapy and tumor subtype were observed. These specific associations could possibly be explained by covariance with TP53 mutation status, which also correlated with tumor subtype. Using supervised analysis, we could not uncover a gene profile that could reliably (&gt;70% accuracy and specificity) predict response to either treatment regimen. [Mol Cancer Ther 2006;5(11):2914–8]

Prognostic and predictive value of changes in tumour cell proliferation in locally advanced breast cancer primarily treated with doxorubicin

We previously reported that high tumour cell proliferation evaluated by Ki-67 expression, high mitotic frequency and high histological grade were associated with resistance to primary doxorubicin monotherapy in locally advanced breast cancer harbouring wild-type (wt) TP53. The aim of our present study was to evaluate the predictive and prognostic impact of proliferation parameters assessed in tumour tissue obtained after chemotherapy, and alterations induced in tumour cell proliferation. While we found a significant reduction in Ki-67 expression and mitotic frequency in tumours with wtTP53 (p=0.001 and p=0.008, respectively), no significant change was recorded in tumours expressing mutant TP53. For histological grade there was no significant change in either group. There was a direct correlation between pre- and post-treatment values for Ki-67 and mitotic frequency in tumours harbouring wtTP53 (p=0.0001 for both), but no correlation in tumours harbouring mutated TP53. High post-treatment Ki-67 expression and mitotic frequency were found to predict doxorubicin resistance only in patients with wtTP53 (p=0.04 and p=0.03, respectively). The prognostic importance of proliferation markers and histological grade was found to be similar whether they were determined in the pre- or post-treatment samples (Ki-67; pre: p=0.02; post: p=0.03; mitotic frequency; p=0.002 and p=0.01, respectively; histological grade; p=0.0001 and p=0.002, respectively). While the reduction in mitotic frequency was associated with improved survival (p=0.03), no significant associations between changes in other parameters and outcome were recorded.

Alternative splicing and mutation status of CHEK2 in stage III breast cancer

The DNA damage checkpoint kinase, CHK2, promotes growth arrest or apoptosis through phosphorylating targets such as Cdc25A, Cdc25C, BRCA1, and p53. Both germline and somatic loss-of-function CHEK2 mutations occur in human tumours, the former linked to the Li-Fraumeni syndrome, and the latter found in diverse types of sporadic malignancies. Here we examined the status of CHK2 by genetic and immunohistochemical analyses in 53 breast carcinomas previously characterized for TP53 status. We identified two CHEK2 mutants, 470T>C (Ile157Thr), and a novel mutation, 1368insA leading to a premature stop codon in exon 13. The truncated protein encoded by CHEK2 carrying the 1368insA was stable yet mislocalized to the cytoplasm in tumour sections and when ectopically expressed in cultured cells. Unexpectedly, we found CHEK2 to be subject to extensive alternative splicing, with some 90 splice variants detected in our tumour series. While all cancers expressed normal-length CHEK2 mRNA together with the spliced transcripts, we demonstrate and/or predict some of these splice variants to lack CHK2 function and/or localize aberrantly. We conclude that cytoplasmic sequestration may represent a novel mechanism to disable CHK2, and propose to further explore the significance of the complex splicing patterns of this tumour suppressor gene in oncogenesis.

TP53 gene mutations predict the response to neoadjuvant treatment with 5-fluorouracil and mitomycin in locally advanced breast cancer

PURPOSE

Recent studies have found an association between certain TP53 mutations and resistance to anthracycline-based primary medical therapy in breast cancer. The purpose of this study was to investigate whether TP53 mutational status also might influence the response to a non-anthracycline-containing regimen in primary breast cancer.

EXPERIMENTAL DESIGN

Thirty-five patients with locally advanced breast cancer were investigated for TP53 mutations before receiving combination chemotherapy with 5-fluorouracil (1000 mg/m(2) on days 1 and 2) and mitomycin (6 mg/m(2) on day 2), administered every 3 weeks for 2-10 cycles in the neoadjuvant setting.

RESULTS

Mutations in the TP53 gene, in particular those affecting loop domains L2 or L3 of the p53 protein, were associated with lack of response to chemotherapy (i.e., increase in the diameter product of tumor lesion by >/=25%; P = 0.177 for all mutations and P = 0.006 for those affecting L2/L3 domains, respectively). No statistically significant correlation between TP53 LOH and response to therapy was seen.

CONCLUSION

This study revealed a significant association between lack of response to 5-fluorouracil and mitomycin and mutations affecting the L2/L3 domains of the p53 protein. Together with our previous finding that such mutations predict resistance to weekly doxorubicin, our data suggest that mutations affecting this particular domain of the p53 protein may cause resistance to several different cytotoxic compounds applied in breast cancer treatment.

Repeated observation of breast tumor subtypes in independent gene expression data sets

Characteristic patterns of gene expression measured by DNA microarrays have been used to classify tumors into clinically relevant subgroups. In this study, we have refined the previously defined subtypes of breast tumors that could be distinguished by their distinct patterns of gene expression. A total of 115 malignant breast tumors were analyzed by hierarchical clustering based on patterns of expression of 534 "intrinsic" genes and shown to subdivide into one basal-like, one ERBB2-overexpressing, two luminal-like, and one normal breast tissue-like subgroup. The genes used for classification were selected based on their similar expression levels between pairs of consecutive samples taken from the same tumor separated by 15 weeks of neoadjuvant treatment. Similar cluster analyses of two published, independent data sets representing different patient cohorts from different laboratories, uncovered some of the same breast cancer subtypes. In the one data set that included information on time to development of distant metastasis, subtypes were associated with significant differences in this clinical feature. By including a group of tumors from BRCA1 carriers in the analysis, we found that this genotype predisposes to the basal tumor subtype. Our results strongly support the idea that many of these breast tumor subtypes represent biologically distinct disease entities.

Predictive value of tumour cell proliferation in locally advanced breast cancer treated with neoadjuvant chemotherapy

We previously reported that defects in apoptotic pathways (mutations in the TP53 gene) predicted resistance to doxorubicin monotherapy. The aim of this study was to evaluate whether cell proliferation, as assessed by mitotic frequency and Ki-67 levels, may provide additional predictive information in the same tumours and to assess any potential correlations between these markers and mutations in the TP53 gene and erbB-2 overexpression. Surgical specimens were obtained from ninety locally advanced breast cancers before commencing primary chemotherapy consisting of weekly doxorubicin (14 mg/m2) for 16 weeks. 38% of the patients had a partial response (PR) to therapy, 52% had stable disease (SD) while 10% had progressive disease (PD). Univariate analysis showed a significant association between a high cell proliferation rate (expressed as a high mitotic frequency) and resistance to doxorubicin (P = 0.001). Further analyses revealed this association to be limited to the subgroup of tumour expressing wild-type TP53 (P = 0.016), and TP53 mutation status was the only factor predicting drug resistance in the multivariate analyses. The finding that a high mitotic frequency, as well as a high Ki-67 staining, correlated to TP53 mutations (P = 0.001 for both), suggests TP53 mutations are the key predictor of drug resistance, although cell proliferation may play an additional role in tumours harbouring wild-type TP53. Regarding overall (OS) and relapse-free survival (RFS), multivariate analyses (Cox' proportional hazards regression) revealed a high histological grade and negative oestrogen receptor (ER) status to be the variables that were most strongly related to breast cancer death (P = 0.001 and P = 0.001, respectively). A key reason for this difference with respect to the factors predicting chemotherapy resistance could be due to the adjuvant use of tamoxifen in all patients harbouring ER-positive tumours.

Gene expression patterns of breast carcinomas distinguish tumor subclasses with clinical implications

The purpose of this study was to classify breast carcinomas based on variations in gene expression patterns derived from cDNA microarrays and to correlate tumor characteristics to clinical outcome. A total of 85 cDNA microarray experiments representing 78 cancers, three fibroadenomas, and four normal breast tissues were analyzed by hierarchical clustering. As reported previously, the cancers could be classified into a basal epithelial-like group, an ERBB2-overexpressing group and a normal breast-like group based on variations in gene expression. A novel finding was that the previously characterized luminal epithelial/estrogen receptor-positive group could be divided into at least two subgroups, each with a distinctive expression profile. These subtypes proved to be reasonably robust by clustering using two different gene sets: first, a set of 456 cDNA clones previously selected to reflect intrinsic properties of the tumors and, second, a gene set that highly correlated with patient outcome. Survival analyses on a subcohort of patients with locally advanced breast cancer uniformly treated in a prospective study showed significantly different outcomes for the patients belonging to the various groups, including a poor prognosis for the basal-like subtype and a significant difference in outcome for the two estrogen receptor-positive groups.

Apolipoprotein E polymorphism and lithogenic factors in gallbladder bile

BACKGROUND

Associations between the polymorphism of apolipoprotein E, which plays an important role in cholesterol metabolism and cholesterol gallstone formation, have been reported recently. Patients with the apo E4 isoform showed increased numbers and cholesterol contents of their stones, a higher frequency of cholesterol crystals in bile, increased susceptibility to gallstone fragmentation by extracorporeal shock-wave lithotripsy and an increase in recurrence rate after dissolution. A recent study, however, showed that fast cholesterol crystallization in bile is associated with multiple stones but not with apo E4. Therefore the mechanism for an increased risk of gallstone formation in patients with the apo E4 isoform still remains under debate.

DESIGN

To clarify this issue we investigated 37 patients with gallstones (10 with the apo E4 allele and 27 without the allele). Gallbladder biles were examined for total cholesterol and other lipids, cholesterol saturation index, crystal observation time, crystal mass, total protein and mucin. Moreover, number of gallstones and cholesterol in gallstones was compared in both groups.

RESULTS

The crystal observation time (2.5 vs. 2.0 days, median) and the cholesterol saturation index (1.34 +/- 0.45 vs. 1.43 +/- 0.74) did not differ significantly between the apo E4 and the non apo E4 group. Total biliary lipids (11.6 +/- 3.8 vs. 9.3 +/- 3.9 g 100 mL-1, P = 0.126) and total biliary cholesterol (21.8 +/- 9.7 vs. 15.7 +/- 7 mmol L-1, P = 0.067) tended to be elevated in the apo E4 group. Crystal mass (3.60 +/- 4.10 vs. 2.38 +/- 2.70 mmol L-1), biliary total protein (8.6 +/- 3.5 vs. 8.3 +/- 6.6 mg mL-1) and mucin (0.55 +/- 0.38 vs. 0.66 +/- 0.67 mg mL-1), number (solitary/multiple) of gallstones and cholesterol in gallstones were not different in both groups of patients.

CONCLUSIONS

In comparison to the non apo E4 patients the apo E4 group showed a trend to elevated biliary cholesterol whereas crystal observation time, cholesterol saturation index, crystal mass, number of gallstones, cholesterol content of gallstones and total protein and mucin were not different. These findings do not suggest an association of the apo E isoform and the formation of cholesterol gallstones

Plasma insulin-like growth factor binding protein-3 proteolysis is increased in primary breast cancer

Fasting blood samples were obtained before definitive surgery or biopsy in 128 patients referred to the department of surgery with suspected or manifest breast cancer. Insulin-like growth factor (IGF)-I, IGF-II and free IGF-I were measured by radioimmunoassay/immunoradiometric assay, while IGFBP-3 proteolysis was evaluated by Western immunoblot. 12 patients had ductal carcinoma in situ benign conditions, while staging revealed metastatic disease in 15 of 16 patients with invasive cancers. IGFBP-3 proteolysis above the normal range was recorded in 19 patients with invasive cancers, but in none of the patients suffering from DCIS/benign conditions. Increased IGFBP-3 proteolysis was most frequently recorded in patients harbouring large tumours and metastatic disease (Stage I: 0/19, 0%; Stage II: 3/45, 7%, Stage III: 9/37, 24%, and Stage IV: 7/15, 47%). IGFBP-3 proteolysis was significantly higher in Stage III (P =0.01) and IV (P< 0.001) patients compared to the other stage groups (P = 0.001). IGF-I and IGF-II correlated negatively to IGFBP-3 proteolysis and age. Plasma levels of IGF-I and -II were significantly lower in patients with elevated IGFBP-3 proteolysis compared to those within the normal range. Our findings reveal alterations in the IGF-system among a substantial number of patients with large primary breast cancers.

[Biosurgical methods tested in 10 patients. Maggots into the wound--do they promote healing?]

Between 07.04.1999 and 06.07.1999 we used sterile maggots for the treatment of 10 patients having acute infections as well as chronic wounds. All patients had had unsuccessful treatment for more than six weeks before we started our regime. Patients with acute infections and most diabetics had the best short-term results. In some diabetics, in chronic arterial occlusive disease (stage 4) and in rare cases of chronic infections like steroid associated wounds or thrombangitis obliterans The treatment had no success or there were complications. The etiologically broad range of wounds and our limited experience with biosurgery limit the result of our study. In spite of that we regard biosurgery to be a very promising part of the range of surgical wound treatment.

Influence of TP53 gene alterations and c-erbB-2 expression on the response to treatment with doxorubicin in locally advanced breast cancer

TP53 status [mutations, immunostaining, and loss of heterozygosity (LOH)], expression of c-erbB-2, bcl-2, and histological grading were correlated to the response to doxorubicin monotherapy (14 mg/m2) administered weekly to 90 patients with locally advanced breast cancer. Mutations in the TP53 gene, in particular those affecting or disrupting the loop domains L2 or L3 of the p53 protein, were associated with lack of response to chemotherapy (P = 0.063 for all mutations and P = 0.008 for mutations affecting L2/L3, respectively). Similarly, expression of c-erbB-2 (P = 0.041), a high histological grade (P = 0.023), and lack of expression of bcl-2 (P = 0.018) all predicted chemoresistance. No statistically significant association between either p53 immunostaining or TP53 LOH and response to therapy was recorded, despite the finding that both were associated with TP53 mutation status (p53 immunostaining, P < 0.001; LOH, P = 0.021). Lack of immunostaining for p53 despite mutation of the TP53 gene was particularly seen in tumors harboring nonsense mutations or deletions/splices (7 of 10 negative for staining compared with 4 of 16 with missense mutations). TP53 mutations (total/affecting L2/L3 domains) were associated with expression of c-erbB-2 (P < 0.001 for both), high histological grade (P = 0.001 and P = 0.025), and bcl-2 negativity (P = 0.003 and P = 0.002). TP53 mutations, histological grade, and expression of bcl-2 (but not LOH or c-erbB-2 expression) all predicted for relapse-free as well as breast cancer-specific survival in univariate analysis (Ps between <0.0001 and 0.0155), but only tumor grade was found to be predictive in multivariate analysis (P = 0.01 and P = 0.0007, respectively). Our data are consistent with the hypothesis that certain TP53 mutations predict for resistance to doxorubicin in breast cancer patients. However, the observation that the majority of patients with TP53 mutations affecting or disrupting the L2/L3 domains with LOH in addition (n = 12) obtained a partial response (n = 4) or stabilization of disease (n = 5) during chemotherapy suggests redundant mechanisms to compensate for loss of p53 function. Our findings are consistent with the hypothesis that other defects may act in concert with loss of p53 function, causing resistance to doxorubicin in breast cancers.

Neuropsychology of first-episode schizophrenia: initial characterization and clinical correlates

OBJECTIVE

Neuropsychological impairments are well documented in schizophrenia and are important targets of treatment. Information about the severity and pattern of deficits after treatment for the first psychotic episode and about relationships between these deficits and syndromal characteristics remains limited.

METHOD

Comprehensive neuropsychological assessments including 41 individual tests were given to 94 patients with first-episode schizophrenia after initial stabilization of psychosis and to a comparison group of 36 healthy volunteers. Profiles of neuropsychological deficits and the relationship of deficits to sex and handedness were examined. Correlations of neuropsychological deficit with a broad range of historical and clinical characteristics, including outcome, were explored.

RESULTS

Patients had a large generalized neuropsychological deficit (1.5 standard deviations compared to healthy volunteers). Patients also had, superimposed on the generalized deficit, subtle relative deficits (less than 0.5 standard deviation compared to their own average profile) in memory and executive functions. Learning/memory dysfunction best distinguished patients from healthy individuals; after accounting for this difference, only motor deficits further distinguished the groups. Patients with higher neuropsychological ability had only memory deficits, and patients with lower ability had both memory and executive deficits. No sex differences were observed beyond the normal advantage for men in motor speed. Dextral patients had less severe generalized deficit. Severity of residual symptoms was associated with greater generalized deficit. Executive and attentional deficits were most linked to global functional impairment and poor outcome.

CONCLUSIONS

The results document a large generalized deficit, and more subtle differential deficits, in clinically stabilized first-episode patients. Learning/memory deficits were observed even in patients with less severe generalized deficit, but the pattern was unlike the amnestic syndrome and probably reflects different mechanisms. Executive and attentional deficits marked the more severely disabled patients, and may portend relatively poor outcome. Failure to develop typical patterns of cerebral dominance may increase the risk for greater generalized deficit.

Effects of treatment with megestrol acetate on the insulin-like growth factor system: time and dose dependency

This study was designed to evaluate time and dose dependency of alterations in insulin-like growth factor (IGF)-I, free IGF-I and the functional status of IGF-binding protein (IGFBP)-3 in breast cancer patients during treatment with megestrol acetate (MA). In 16 patients receiving MA 160 mg daily, total IGF-I levels increased gradually (significant after 3 days on treatment) by a maximum of 2.66-fold after 5-6 months on treatment. However, free (readily dissociable) IGF-I levels increased to a smaller extent (1.23-2.15-fold). This discrepancy may be due to an increase in intact IGFBP-3 determined by Western ligand blotting (WLB). Similar findings were observed in 12 patients treated with MA in escalating doses from 40-800 mg daily. A dose-dependent increase in IGF-I was observed up to a dose level of 120 mg daily. We conclude that treatment with MA caused a profound increase in plasma levels of total IGF-I accompanied by a moderate increase in free IGF-I. This may explain the anabolic effects of MA in patients suffering from cachexia, but refute the hypothesis that alterations in the IGF-system may contribute to the antitumour effects of MA in breast cancer patients.

Predictors of treatment response from a first episode of schizophrenia or schizoaffective disorder

OBJECTIVE

This study examined the treatment response of patients with first-episode schizophrenia and schizoaffective disorder and potential predictors of response.

METHOD

First-episode patients were assessed on measures of psychopathology, cognition, social functioning, and biological parameters and treated according to a standardized algorithm.

RESULTS

One hundred eighteen patients (52% male, mean age 25.2 years) entered the study. The cumulative percentage of patients responding by 1 year was 87%; the median time to response was 9 weeks. The following variables were significantly associated with less likelihood of response to treatment: male sex, obstetric complications, more severe hallucinations and delusions, poorer attention at baseline, and the development of parkinsonism during antipsychotic treatment. Variables not significantly related to treatment response were diagnosis (schizophrenia versus schizoaffective disorder), premorbid functioning, duration of psychotic symptoms prior to study entry, baseline disorganization, negative and depressive symptoms, baseline motor function, akathisia and dystonia during treatment, growth hormone and homovanillic acid measures, psychotic symptom activation to methylphenidate, and magnetic resonance measures.

CONCLUSIONS

Patients with first-episode schizophrenia and schizoaffective disorder have high rates of response to antipsychotic treatment; there are specific clinical and pathobiologic predictors of response.

Predictors of relapse following response from a first episode of schizophrenia or schizoaffective disorder

BACKGROUND

We examined relapse after response to a first episode of schizophrenia or schizoaffective disorder.

METHODS

Patients with first-episode schizophrenia were assessed on measures of psychopathologic variables, cognition, social functioning, and biological variables and treated according to a standardized algorithm. The sample for the relapse analyses consisted of 104 patients who responded to treatment of their index episode and were at risk for relapse.

RESULTS

Five years after initial recovery, the cumulative first relapse rate was 81.9% (95% confidence interval [CI], 70.6%-93.2%); the second relapse rate was 78.0% (95% CI, 46.5%-100.0%). By 4 years after recovery from a second relapse, the cumulative third relapse rate was 86.2% (95% CI, 61.5%-100.0%). Discontinuing antipsychotic drug therapy increased the risk of relapse by almost 5 times (hazard ratio for an initial relapse, 4.89 [99% CI, 2.49-9.60]; hazard ratio for a second relapse, 4.57 [99% CI, 1.49-14.02]). Subsequent analyses controlling for antipsychotic drug use showed that patients with poor premorbid adaptation to school and premorbid social withdrawal relapsed earlier. Sex, diagnosis, obstetric complications, duration of psychotic illness before treatment, baseline symptoms, neuroendocrine measures, methylphenidate hydrochloride challenge response, neuropsychologic and magnetic resonance imaging measures, time to response of the initial episode, adverse effects during treatment, and presence of residual symptoms after the initial episode were not significantly related to time to relapse.

CONCLUSIONS

There is a high rate of relapse within 5 years of recovery from a first episode of schizophrenia and schizoaffective disorder. This risk is diminished by maintenance antipsychotic drug treatment.

Intravenous infusion of glucose and the vasodilator sodium nitroprusside in combination with local hyperthermia: effects on tumour pH and tumour response in the BT4An rat tumour model

The influence of sodium nitroprusside (SNP) induced hypotension on the extra-cellular tumour pH during local hyperthermia (HT), and on the cytotoxic effect of HT, was studied in the BT4An tumour transplanted to the hind limb of BD IX rats. Experiments with intravenous infusion of glucose before the HT/SNP combination were also performed. Local waterbath HT was given at 44 degrees C. Sodium nitroprusside was administered as a continuous i.v. infusion to lower the mean arterial blood pressure to 60 mmHg. Glucose was given as an i.v. infusion at a dosage of 4.8 g/kg body weight in 60 min before HT. Extracellular tumour pH was measured by a needle type glass electrode. The tumour pH fell from 7.19 to 6.81, on average, after 60 min HT. Sodium nitroprusside induced hypotension during HT did not increase the pH fall after 1 h HT, but the pH 60 min after discontinuation of HT was lower in this group than in the HT alone group. Pretreatment with glucose before HT gave similar results as the HT/SNP combination. When glucose was given before HT/SNP a highly relevant decline in tumour pH during HT from 7.22 to 5.95 was observed. In a separate tumour response experiment adding SNP to HT was found to prolong the tumour growth time. Pre-treatment with glucose before the HT/SNP combination prolonged the tumour growth time slightly. The applicability of this treatment protocol in the clinical treatment of patients is discussed.

Differential distribution of five members of the matrix metalloproteinase family and one inhibitor (TIMP-1) in human liver and skin

Matrix metalloproteinases represent a family of zinc-dependent proteolytic enzymes thought to be involved in normal and disease-related tissue remodeling processes. Increasing information about these enzymes is becoming available concerning their primary sequences, regulation at the mRNA level, activation of proenzymes, and modulation of enzyme activity by tissue inhibitors. In contrast, their morphological distribution and biological functions in normal tissues are poorly understood. In the present report, the comparative distribution of five members (gelatinase-A, gelatinase-B, matrilysin, stromelysin-1, and stromelysin-3) of the matrix metalloproteinase family and of one inhibitor (TIMP-1) has been morphologically analyzed in human liver and skin with the aid of new monospecific antibodies. Because of their common designation as matrix proteinases, these enzymes might have been expected to be distributed throughout these tissues, or at least in the connective tissue. However, each member of the family produces a highly specific pattern, staining structures such as arteriolar smooth muscle cells, myoepithelial cells in secretory portions or the luminal lining in excretory ducts of dermal sweat glands, liver bile canaliculi, or structures surrounding peripheral nerve axons. No reactivity is detected in rat tissues.

Differential effect of carbamazepine and valproate monotherapy on plasma levels of oestrone sulphate and dehydroepiandrosterone sulphate in male epileptic patients

Steroid sulphates such as oestrone sulphate (OE1S) and dehydroepiandrosterone sulphate (DHEAS) have been suggested to be of biological importance in different disease states such as breast cancer and atherosclerosis. Previous studies have shown that drugs such as aminoglutethimide and rifampicin that induce P450-dependent mixed-function oxygenases selectively suppress plasma OE1S levels. The aim of this study was to evaluate the influence of treatment with carbamazepine, an antiepileptic drug known to stimulate mixed-function oxygenases, on plasma levels of OE1S and DHEAS. We measured plasma OE1S and DHEAS together with other plasma oestrogens and androgens in male epileptic patients before and during carbamazepine monotherapy. Patients treated with valproate monotherapy acted as a control group. Treatment with carbamazepine decreased plasma OE1S levels from a mean value of 810.8 to 411.6 pmol/l (mean suppression to 50.7% of pretreatment levels, P < 0.001). Similarly, the ratio of OE1S to OE1 fell to 59.9% of pretreatment levels (P < 0.001)). DHEAS decreased from a mean level of 4.9 mumol/l before treatment to 3.0 mumol/l during carbamazepine therapy (mean reduction to 62.7% of pretreatment levels (P < 0.001), while the ratio of DHEAS to DHEA fell to 63.0% of pretreatment values (P < 0.01). No significant change in plasma levels of the other oestrogens or androgens measured was observed. Treatment with valproate caused a slight decrease in FSH levels (P < 0.05), but no change in any of the other hormones measured was observed. Studies are warranted to evaluate the possible effects of long-term treatment with carbamazepine on the risk of developing endocrine-sensitive tumours and cardiovascular disease and also the possible effects of alterations in plasma DHEAS on epileptic activity.

Absence of p21 expression is associated with abnormal p53 in human breast carcinomas

The p53 tumour-suppressor gene is important in the regulation of cell growth and apoptosis, and loss of functional wild-type activity may be associated with tumour formation and resistance to therapy. Differentiation of functionally normal wild-type protein from mutant or abnormal protein remains difficult using either immunohistochemical assays or mutational DNA sequencing. p21(WAF1/CIP1) (p21) is induced by wild type p53 and plays an important role in promoting cell cycle arrest. To test the hypothesis that p21 protein expression may act as a downstream marker of tumours from patients with locally advanced breast cancer before treatment with doxorubicin, pretreatment p53 status had been characterized in 63 tumours by p53 protein immunostaining and DNA mutational analysis. There was a significant association between immunostaining for p53 and the presence of p53 mutations (P = 0.01). Of 56 patients available for determination of p21, 31 (55%) expressed p21 protein. Twenty-eight out of 31 patients (90%) positive for p21 had low negative p53 protein expression, whereas only 3 of 13 patients (23%) with high p53 expressed p21 (P = 0.009). No association was seen between p21 protein expression and p53 mutations (P = 0.24). The combination of p53 and p21 immunostaining results improved the specificity of the immunostaining but at a cost of significant reduction in sensitivity. Immunohistochemical assessment of p21 protein expression is inversely associated with abnormal p53 protein in human breast cancer. The detection of p21 protein expression in combination with p53 protein expression did not improve the ability of immunohistochemistry (IHC) to differentiate between normal and mutant p53 protein.