Characterization of clinicopathological features, treatment practices, and outcomes among Finnish advanced breast cancer patients in real-life clinical practice

PURPOSE

In recent years, several new targeted therapies have emerged for advanced breast cancer (aBC). However, real-life data specific to aBC and different breast cancer subtypes are scarce. This retrospective cohort study was designed to describe the distribution of aBC subtypes, incidence, treatment patterns, survival, and PIK3CA hotspot mutation frequency.

METHODS

The study included all patients in the Hospital District of Southwest Finland diagnosed with aBC between 2004 and 2013 and with a sample available in Auria Biobank. In addition to registry-based data collection, 161 HR+/HER2- aBCs were screened for PIK3CA mutations.

RESULTS

Altogether, 54.7% of the 444 patients included in the study had luminal B subtype. The smallest representations were in HR-/HER2+ (4.5%) and triple-negative (5.6%) subgroups. The percentage of aBC among all diagnosed breast cancers increased until 2010, after which it remained stable. The triple-negative cancers were associated with shorter median overall survival (5.5 months) compared to other subgroups (16.5-24.6 months). Most (84%) triple-negative cancers also metastasized during the first two years, whereas this was more evenly distributed over time in other subgroups. Of the HR+/HER2- tumors, 32.3% harbored a PIK3CA hotspot mutation. These patients, however, did not have inferior survival compared to patients with PIK3CA wild-type cancers.

CONCLUSION

This study described real-world aBC subgroups and indicated that the clinical outcomes of subgroups vary. Although PIK3CA hotspot mutations did not lead to inferior survival, they are relevant as possible treatment targets. Overall, these data could be utilized to further evaluate the subgroup-specific medical needs in breast cancer.

Overall survival of individuals with metastatic cancer in Sweden: a nationwide study

Aims

Consistent improvements for overall survival (OS) have been reported for individuals with metastatic cancer. Swedish population-based registers allow national coverage and long follow-up time. The aim of this study was to estimate and explore long-term OS of individuals diagnosed with metastatic cancer using Swedish nationwide health registers.

Methods

Individuals with metastatic breast (MBC), non-small cell lung (MNSCLC), ovary (MOC) or colorectal cancer (MCRC) or metastatic malignant melanoma (MMM) were identified in the Swedish national cancer register and national patient registers. Survival was estimated and stratified by available variables. Potential cure fractions were estimated using mixture cure models.

Results

In total, approximately 69,000 individuals were identified. The most common cancers were MCRC (36.2%) and MNSCLC (29.5%). Men were more frequently diagnosed with MNSCLC, MCRC, and MMM compared to women. Except for MOC, about 50% of individuals were 70 years or older at diagnosis. Throughout the study period survival differed across cancers. The longest median OS was observed for individuals with MOC and MBC. At 10 years of follow-up, the survival curves flatten at a survival rate of approximately 10% for all cancers except MNSCLC. The youngest age groups had the longest median OS. Increased survival was also observed for individuals diagnosed in 2015 and 2018 compared to individuals diagnosed during earlier years. The estimated cure fractions were 4% for MBC, 1.5% for MNSCLC, 6.8% for MCRC, 8.6% for MOC and MMM.

Conclusions

Long-term survival has been assessed across all indications except for NSCLC.. The findings may be relevant for healthcare planning to meet the needs of future patients and potential long-term survivors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14255-w.

Use of classifiers to optimise the identification and characterisation of metastatic breast cancer in a nationwide administrative registry

BAKGROUND

The prognosis for patients with metastatic breast cancer (MBC) is substantially worse when compared with patients with earlier stage disease. Therefore, understanding the differences in epidemiology between these two patient groups is important. Studies using population-based cancer registries to identify MBC are hampered by the quality of reporting. Patients are registered once (at time of initial diagnosis); hence only data for patients with de novo MBC are identifiable, whereas data for patients with recurrent MBC are not. This makes accurate estimation of the epidemiology and healthcare utilisation of MBC challenging. This study aimed to investigate whether machine-learning could improve identification of MBC in national health registries.

MATERIAL AND METHODS

Data for patients with confirmed MBC from a regional breast cancer registry were used to train machine-learning algorithms (or 'classifiers'). The best performing classifier (accuracy 97.3%, positive predictive value 85.1%) was applied to Swedish national registries for 2008 to 2016.

RESULTS

Mean yearly MBC incidence was estimated at 14 per 100,000 person-years (with 18% diagnosed de novo and 76% of the total with HR-positive MBC).

CONCLUSION

To our knowledge, this is the first study to use machine learning to identify MBC regardless of stage at diagnosis in health registries covering the entire population of Sweden.

Socioeconomic cost of AML in Sweden—A population‐based study using multiple nation‐wide registers

Acute myeloid leukemia (AML) is associated with a high economic and clinical burden. Recently novel therapies have been added to standard treatment regimens. Here, we evaluated the economic impact of AML up until the introduction of these novel therapies. Individual data on 2954 adult patients diagnosed from 2007 to 2015 from five Swedish national population‐based registers were used, enabling analyses from diagnosis to either death or 5‐year follow‐up for survival, inpatient and outpatient costs, costs of prescribed drugs, sick leave, and early retirement. Costs per patient were stratified by age group, treatment options, and FLT3‐ITD status. The expected 5‐year costs per patient differed substantially between age groups. Patients aged 18–59 years had an expected mean cost per patient of €170,748, while age groups 60–69 years, 70–79 years, and >80 years incurred an expected mean cost of €92,252, €48,344, and €24,118, respectively, over 5 years. Patients <60 years undergoing stem cell transplantation had the highest costs (€228,525 over 5 years). About 60% of costs for these patients were from hospitalizations and 20% from sick leave and early retirement; cost per day was highest from the first admission to complete remission. This study provides a baseline for socioeconomic evaluations of novel therapies in AML in Sweden.

Abstract PS5-44: Pik3ca mutations among hormone receptor positive and HER-2 negative advanced breast cancer patients in Finland

Background: Several new medicinal products have been introduced for the treatment of advanced breast cancer (aBC) in recent years, many of which are indicated for a specific patient population. One of these compounds is alpelisib, a phosphatidylinositol 3-kinase (PI3K) inhibitor, which has shown efficacy in the treatment of hormone receptor positive and human epidermal growth factor receptor 2 negative (HR+/HER2-) advanced breast cancer (aBC) harboring phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) “hotspot” mutations, i.e. mutations affecting the helical (E542K and E545K) and kinase (H1047R) domains. In this retrospective register-based study, the frequency of PIK3CA gene mutations as well as survival among HR+/HER2- aBC patients in Finland was analyzed.

Methods: This study utilized retrospective register-based data from the Hospital District of Southwest Finland (Auria Biobank), which covers approximately 20% of the population in Finland. Patients diagnosed with aBC between 2004─2013 were identified using ICD-10 code C50* (breast cancer) together with customized text mining algorithms to extract metastatic patients. Tumor biomarker data including estrogen receptor (ER), progesterone receptor (PR), and HER2 status were used to identify HR+/HER2- patients. The formalin fixed paraffin embedded (FFPE) tumor tissue samples available for these patients in the Auria Biobank’s tissue archives were screened for PIK3CA mutations with next generation sequencing. Study follow-up period was defined to start from the date of aBC diagnosis and to continue until death or end of 2016, whichever occurred first. Clinical pathology and survival data were collected from the Auria Biobank and electronic medical records of the Hospital District of Southwest Finland. Overall survival (OS) was estimated using the Kaplan-Meier method.

Results: Altogether 444 adult female patients with aBC were identified. HR and HER2 status were available for 377 patients (85%), out of which 274 (73%) were HR+/HER2-. Representative FFPE tumor samples were available for 187 patients and PIK3CA was successfully screened in 161 patients. Out of the sequenced HR+/HER2- samples, 53.4% showed mutation in the PIK3CA gene and 46.6% wild type (wt) PIK3CA gene. Approximately one third (32.3% n=52) of the samples represented PIK3CA hotspot mutations and 18% (n=29) of these displayed more than one PIK3CA variant. The most common PIK3CA hotspot mutation was H1047R. HR+/HER2- patients with the wt PIK3CA gene showed slightly shorter OS compared to patients showing PIK3CA hotspot mutations (18.9 months (95% CI: 14.1-25.1) vs. 22.3 months (95% CI: 17.0-26.3). Higher portion of the wt patients also developed metastases within 1 year from the primary diagnosis compared to the patients with PIK3CA hotspot mutations (41.3% vs. 25.0%). At the time of diagnosis, 92.0% of the wt and 84.6% of the PIK3CA hotspot mutated population was 50 years or older, respectively.

Conclusion: Approximately one third of the HR+/HER2- aBC patient cohort in Finland had at least one variant of PIK3CA hotspot mutations in line with the SOLAR-1 clinical trial population. The OS did not differ markedly between the patients with wt and hotspot mutated PIK3CA gene. The short OS of the patients is probably due to the fact that the patients were treated before the availability of CDK4/6is as a treatment option.

Citation Format: Krista Heinolainen, Silva Saarinen, Antti Ellonen, Antti Karlsson, Meri Utriainen, Simona Vertuani, Barbro Holm. Pik3ca mutations among hormone receptor positive and HER-2 negative advanced breast cancer patients in Finland [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS5-44.

Abstract P2-08-03: Machine learning to identify and characterize metastatic breast cancer patients in Sweden: A population-based study. CLEE011ASE01

Background: Treatment decisions for metastatic breast cancer (mBC) patients are increasingly complex and this patient subset is poorly characterized. In Sweden, despite the availability of national health registers, it is currently difficult to identify mBC patients’ true prevalence and characteristics at the national level due to lack of variables or missing information on recurrence from early to late disease.

Aim: Develop an algorithm trained to identify mBC patients in Swedish national health registers to estimate the number of mBC patients and to describe their characteristics and survival outcomes.

Methods: This study was a retrospective database study performed on Swedish national data (National Patient Register, Prescribed Drug Register, Cancer Register and the Cause of Death Register) linked with metastatic status, outcome and biomarker data from a regional BC register (Uppsala University Hospital) via unique personal identification number.

The regional BC register data, containing medical records of known mBC and non-mBC patients between 2009-2016, were divided into a training set (n=2,680) and a test set (n=670). Based on known mBC patients’ unique features, derived from linked national data, we developed a support-vector machine (SVM) trained to identify mBC patients (further detailed in the poster). The model’s performance to classify mBC patients was measured in the test set; accuracy: 97.3%, sensitivity: 90.0%, specificity: 98.2%, balanced accuracy: 94.1%. The SVM algorithm was utilized to predict prevalent mBC cases 2009-2016 nationally.

Kaplan-Meier estimates were used to model overall survival (OS) as defined from date of first metastatic diagnosis (ICD10 C78 and/or C79). Cox proportional hazard models were used to test the association between hormone receptor status (HR+/HR-) and de novo/recurrent patients. Patients were assumed to be HR+ if they had ≥2 endocrine prescriptions and de novo in case of DFS ≤3 months.

Results: Between 2009 and 2016 we found a total of 150,235 patients alive with a BC diagnosis. Within this population the SVM algorithm identified a subset of 13,826 (9.2%) mBC patients corresponding to an incidence of 1,318 per year (13.7 per 100,000) and a prevalence of 5,171 per year (53.8 per 100,000). Median age at mBC diagnosis was 67.5 years and median survival was estimated at 29.8 months. 18.3% of the total mBC population were de novo patients. Median age at diagnosis was 68.7 years for de novo mBC and 67.2 years for recurrent mBC, and survival was estimated at 30.1 months and 29.7 months, respectively, with a slightly better prognosis for de novo patients (HR: 0.92; p-value&lt;0.01) after adjusting for age and HR status. HR+ expression showed statistically significant association with OS (HR: 0.50; p-value&lt;0.001).

Median survival was calculated for the mBC population by age group. Patients &lt;50 years, 50-70 years and &gt;70 years at mBC diagnosis had a median survival of 43.3, 37.2, 20.1 months, respectively.

Conclusion: Previous studies have used machine learning for cancer detection or prognostication. Here we show that machine learning algorithms can be applied to identify patient subsets in national population health registers. With this study design we have been able to describe the epidemiology and survival of the full national Swedish mBC population; to our knowledge this is the first study to do so.

Citation Format: Henrik Lindman, Mate Szilcz, Jonatan Freilich, Peter Carlqvist, Simona Vertuani, Barbro Holm. Machine learning to identify and characterize metastatic breast cancer patients in Sweden: A population-based study. CLEE011ASE01 [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-08-03.

Abstract P1-16-10: Treatment patterns and outcomes of different subtypes of metastatic breast cancer patients in a Swedish real world setting with a focus on HER2-/HR+ subtype

Introduction: The most frequent molecular subtype of metastatic breast cancer (MBC) is the HER2-/HR+ subtype. While there are several treatments available for HER2-/HR+ MBC patients, there is limited knowledge about how patients are treated in a real world setting. In this retrospective study, the aim was to describe the duration of four initial treatment lines, treatment patterns and outcomes in MBC subtypes, with a focus on the HER2-/HR+ subtype.

Methods: The population is a cohort of 370 MBC patients diagnosed during '09-´16 in Uppsala County, Sweden. Data were collected from a regional breast cancer registry which included medical records. The subtypes were HER2-/HR+(59%); HER2+/HR+(12%); HER2+/HR-(7%) and HER2-/HR-(12%) based on immunohistochemistry (IHC) and in situ hybridization (ISH) tests, 11% of records had missing data on subtypes. Kaplan-Meier estimates were used to model duration of treatment line, progression-free survival (PFS) and overall survival (OS). Cox proportional hazard models were used to test the association, expressed in hazard ratios (HR), between the subtypes and PFS and OS.

Results: The median PFS and OS of HER2-/HR+ subtype were 10.6 and 36.7 months, respectively. Compared to the HER2-/HR+ patients, a statistically significant difference was found for HER2-/HR- patients in terms of PFS (HR: 2.1; p-value&lt;0.001) and OS (HR: 3.6; p-value&lt;0.01), indicating a worse prognosis. HER2+/HR+ and HER2+/HR-patients had similar PFS and OS results to HER2-/HR+ patients.

A statistically significant association was found between HR+ expression and OS (HR: 0.5; p-value&lt;0.001) and not between HER2+ expression and OS (HR: 1.0; p-value 0.79 ).

The median duration of treatment decreased with increasing treatment lines; HER2-/HR+ patients' first-line treatment lasted 7.2, second-line 5.5, third-line 4.7 and fourth-line 4.4 months. The proportion of chemotherapy increased with the number of treatment lines: 32%, 38%, 46% and 59% for first to fourth line, respectively.

The ten most used drugs of HER2-/HR+ cohort are summarized in Table 1. In total, endocrine therapy was given during 66% of the total treatment duration.

Table 1:Ten most used drugs of HER2-/HR+N=197Patient-years (sum of treatment durations)Relative frequency of patient-years (%). Total=511 yearsLetrozole19037Tamoxifen5611Capecitabine5511Exemestane438Fulvestrant316FEC245Paclitaxel235Docetaxel143Vinorelbine112Everolimus92

Conclusion: In this retrospective study of MBC patients, the expression of HR showed an individual positive impact of OS with a 50% reduction in hazards. In our cohort only the prognosis of HER2-/HR- patients were significantly worsened both in terms of PFS and OS compared to HER2-/HR+ subtype. In the analysis of HER2-/HR+ subtype, letrozole was the most durable therapy, used 37% of total treatment time. The most used chemotherapy was capecitabine, used in 11% of the treatment time.

Citation Format: Lindman H, Szilcz M, Freilich J, Carlqvist P, Vertuani S, Anell B, Holm B. Treatment patterns and outcomes of different subtypes of metastatic breast cancer patients in a Swedish real world setting with a focus on HER2-/HR+ subtype [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-16-10.

A systematic literature review of time to return to work and narcotic use after lumbar spinal fusion using minimal invasive and open surgery techniques

BACKGROUND

Chronic low back pain is a common health problem for adult workers and causes an enormous economic burden. With the improvement of minimally invasive surgical techniques (MIS) in spinal fusion and the development of fusion devices, more lumbar operations are today being performed through a less invasive technique. When compared with open surgeries (OS), MIS has demonstrated better clinical outcomes including operation time, blood loss, complication rates and length of hospital stay. The aim of this review was to identify and summarize evidence on the time to return to work and the duration of post-operation narcotic use for patients who had lumbar spinal fusion operations using MIS and OS techniques.

METHODS

A systematic literature review was performed including studies identified from PubMed, EMBASE, the Cochrane Collaboration, and the Centre for Review and Dissemination (CRD) (January 2004–April 2014) for publications reporting on time to return to work and post-operation narcotic use after MIS or OS lumbar spinal fusion surgeries.

RESULTS

Out of a total of 36 included studies, 28 reported on the time to return to work and 17 on the narcotic use after MIS or OS. Four studies described the time to return to work directly comparing MIS and OS. Three studies, from the US, directly compared the duration of narcotic use between MIS- transforaminal lumbar interbody fusion (TLIF) and OS-TLIF. In addition to the time to return to work, 23 studies reported on the rate of return to work and the employment rate before and after surgery, and two Swedish studies presented sick leave data.

CONCLUSION

There is a gap of good quality data describing the time to return to work and narcotic use after lumbar spinal fusion operations using MIS or OS techniques. However, the current systematic literature review indicates that patients who have lumbar spinal fusion operations, with the MIS procedure, generally return to work after surgery more quickly and require less post-operation narcotics for pain control compared to patients who have OS.

Fusidic acid betamethasone lipid cream

Bacterial infections of the skin and soft tissues are frequent disorders. They can be primitive infections (e.g. impetigo, folliculitis) or secondary infections complicating other diseases, particularly atopic dermatitis. The most common aetiologic agent is Staphylococcus aureus. Topical antibiotic therapy may be sufficient in many instances to control these infections. Fusidic acid is an antibiotic used topically on the skin which is very active against S. aureus, including methicillin-resistant strains, and other Gram-positive bacteria. Resistance rates to fusidic acid are stably low. A fusidic acid and betamethasone formulation in a lipid-enriched cream (lipid cream) has been recently developed in order to provide effective antibacterial and anti-inflammatory activities in conjunction with a powerful emollient and moisturising effect. This preparation may be especially useful in patients with atopic-infected eczema.

A Cost-Effectiveness Analysis of Minimally Invasive versus Open Surgery Techniques for Lumbar Spinal Fusion in Italy and the United Kingdom

OBJECTIVE

Evaluate the cost-effectiveness of minimally invasive surgery (MIS) compared with open surgery (OS) techniques for one- or two-level lumbar spinal fusion in the treatment of degenerative lumbar spinal conditions in the United Kingdom and Italy.

METHODS

A health economic model was developed on the basis of results from a systematic literature review and meta-analysis to determine the cost-effectiveness of MIS compared with OS for lumbar spinal fusion. The analysis was conducted from a health care payer perspective. Parameters included in the model were surgery, blood loss, duration of hospitalization, postoperative complications, and health-related quality of life (HRQOL). Cost-effectiveness was determined by the incremental cost per quality-adjusted life-year gained.

RESULTS

MIS was the dominant strategy compared with OS (i.e., yielding both cost savings and improved HRQOL). Cost savings were driven mainly by shorter length of hospital stay, reduced blood loss, and fewer complications such as surgical site infection. The total cost saving per procedure was €973 for Italy and €1666 for the United Kingdom, with an improvement of 0.04 quality-adjusted life-year over 2 years in HRQOL. One-way sensitivity analyses and predefined scenario(s) analyses confirmed the robustness of the model.

CONCLUSIONS

MIS is a less expensive and a more effective treatment compared with OS for spinal lumbar fusion in both Italy and the United Kingdom. Lower downstream costs and increased HRQOL in the MIS group compensate for potential higher upfront costs of MIS implants and surgery equipment.

The topical vehicle as a key factor in the management of the psoriatic patients' therapy

This review deals with the importance of the topical vehicle as a key factor in the management of the psoriatic patients' therapy.

VE-PTP regulates VEGFR2 activity in stalk cells to establish endothelial cell polarity and lumen formation

Vascular endothelial growth factor (VEGF) guides the path of new vessel sprouts by inducing VEGF receptor-2 activity in the sprout tip. In the stalk cells of the sprout, VEGF receptor-2 activity is downregulated. Here, we show that VEGF receptor-2 in stalk cells is dephosphorylated by the endothelium-specific vascular endothelial-phosphotyrosine phosphatase (VE-PTP). VE-PTP acts on VEGF receptor-2 located in endothelial junctions indirectly, via the Angiopoietin-1 receptor Tie2. VE-PTP inactivation in mouse embryoid bodies leads to excess VEGF receptor-2 activity in stalk cells, increased tyrosine phosphorylation of VE-cadherin and loss of cell polarity and lumen formation. Vessels in ve-ptp^−/− teratomas also show increased VEGF receptor-2 activity and loss of endothelial polarization. Moreover, the zebrafish VE-PTP orthologue ptp-rb is essential for polarization and lumen formation in intersomitic vessels. We conclude that the role of Tie2 in maintenance of vascular quiescence involves VE-PTP-dependent dephosphorylation of VEGF receptor-2, and that VEGF receptor-2 activity regulates VE-cadherin tyrosine phosphorylation, endothelial cell polarity and lumen formation.

Vascular endothelial growth factor is implicated in blood vessel development. In zebrafish, Hayashi et al. find that blood vessel development is dependent on the suppression of vascular endothelial growth factor by the phosphatase VE-PTP, which is recruited by activation of the angiopoietin receptor Tie2.

Vaccination with dendritic cells loaded with tumor apoptotic bodies (Apo-DC) in patients with chronic lymphocytic leukemia: effects of various adjuvants and definition of immune response criteria

We previously demonstrated that autologous dendritic cells that have endocytosed apoptotic bodies of chronic lymphocytic leukemia (CLL) cells (Apo-DC) can stimulate antileukemic T cell responses in vitro. In this phase I study, we vaccinated 15 asymptomatic CLL patients at five time points with Apo-DC administered intradermally either alone (cohort I), or in combination with subcutaneous granulocyte-macrophage-colony-stimulating-factor (GM-CSF) (cohort II) or with GM-CSF and intravenous low-dose cyclophosphamide (cohort III). Aim of the study was to evaluate the safety and immunogenicity of Apo-DC alone or in combination with GM-CSF and low-dose cyclophosphamide in CLL patients. All patients completed the vaccination schedule without dose-limiting toxicity. No objective clinical responses were seen. Vaccine-induced leukemia-specific immune responses were evaluated by IFN-γ ELISpot and proliferation assays over a 52 weeks observation period and immune response criteria were defined. According to these criteria, 10/15 patients were defined as immune responders. The frequency of immune-responding patients was higher in cohorts II (3/5) and III (5/5) than in cohort I (2/5). In order to further characterize the induced immune response, estimation of secreted cytokines and CD107-degranulation assay were performed. Clustering of T and CLL cells was observed in CD107-degranulation assay and visualized by confocal microscopy. Additionally, assessment of regulatory T cells (T(regs)) revealed their significantly lower frequencies in immune responders versus non-responders (P < 0.0001). Cyclophosphamide did not reduce T(regs) frequency. In conclusion, vaccination with Apo-DC + GM-CSF and cyclophosphamide was safe and elicited anti-CLL immune responses that correlated inversely with T(regs) levels. Lack of clinical responses highlights the necessity to develop more potent vaccine strategies in B cell malignancies.

Angiomotin-Like Protein 1 Controls Endothelial Polarity and Junction Stability During Sprouting Angiogenesis

Rationale: We have previously shown that angiomotin (Amot) is essential for endothelial cell migration during mouse embryogenesis. However, ≈5% of Amot knockout mice survived without any detectable vascular defects. Angiomotin-like protein 1 (AmotL1) potentially compensates for the absence of Amot as it is 62% homologous to Amot and exhibits similar expression pattern in endothelial cells.

Objective: Here, we report the identification of a novel isoform of AmotL1 that controls endothelial cell polarization and directional migration.

Methods and Results: Small interfering RNA–mediated silencing of AmotL1 in mouse aortic endothelial cells caused a significant reduction in migration. In confluent mouse pancreatic islet endothelial cells (MS-1), AmotL1 colocalized with Amot to tight junctions. Small interfering RNA knockdown of both Amot and AmotL1 in MS-1 cells exhibited an additive effect on increasing paracellular permeability compared to that of knocking down either Amot or AmotL1, indicating both proteins were required for proper tight junction activity. Moreover, as visualized using high-resolution 2-photon microscopy, the morpholino-mediated knockdown of amotl1 during zebrafish embryogenesis resulted in vascular migratory defect of intersegmental vessels with strikingly decreased junction stability between the stalk cells and the aorta. However, the phenotype was quite distinct from that of amot knockdown which affected polarization of the tip cells of intersegmental vessels. Double knockdown resulted in an additive phenotype of depolarized tip cells with no or decreased connection of the stalk cells to the dorsal aorta.

Conclusions: These results cumulatively validate that Amot and AmotL1 have similar effects on endothelial migration and tight junction formation in vitro. However, in vivo Amot appears to control the polarity of vascular tip cells whereas AmotL1 mainly affects the stability of cell–cell junctions of the stalk cells.

HER-2/neu mediated down-regulation of MHC class I antigen processing prevents CTL-mediated tumor recognition upon DNA vaccination in HLA-A2 transgenic mice

To study DNA vaccination directed against human HER-2 in the HHD mouse Tg strain, we created a novel HER-2-expressing syngeneic tumor transplantation model. We found that a DNA vaccine encoding the full length HER-2 DNA protected HHD mice from HER-2(+) tumor challenge by a CTL independent mechanism. A more efficient approach to induce HLA-A2 restricted CTLs, through immunization with a multi-epitope DNA vaccine expressing the HLA-A2 restricted HER-2 369-377, 435-443 and 689-697 epitopes, resulted in high numbers of peptide specific T cells but failed to induce tumor protection. Subsequently we discovered that HER-2 transfected tumor cells down-regulated MHC class I antigen expression and exhibited a series of defects in the antigen processing pathway which impaired the capacity to produce and display MHC class I peptide-ligands to specific CTLs. Our data demonstrate that HER-2 transfection is associated with defects in the MHC class I presentation pathway, which may be the underlying mechanism behind the inability of CTLs to recognize tumors in this HLA-A2 transgenic model. As defective MHC class I presentation may be a common characteristic of HER-2 expressing tumors, vaccines targeting HER-2 should aim at inducing an integrated immune response where also CD4(+) T cells and antibodies are important components.

Retinoic acid elicits cytostatic, cytotoxic and immunomodulatory effects on uveal melanoma cells

The current therapy of uveal melanoma (UM) metastases remains inefficient, which warrants the development of new treatment modalities. For the first time we investigated the effects of retinoic acid (RA) on a panel of UM cell lines and found that RA induces morphological changes compatible with differentiation, suppresses proliferation and causes apoptosis in these cells. RA treatment resulted in an increase of p21, p27 and p53 protein levels and G1 arrest in UM cells, which correlated with significant down-modulation of surface Her2/neu proto-oncogene expression. In addition, RA-treated UM cells exhibited increased sensitivity to both MHC class I-restricted killing by cytotoxic T lymphocytes and NK cell-mediated lysis that were accompanied by more efficient conjugate formation between UM cells and killer lymphocytes. Taken together, our results implicate UM as a new target for treatment with retinoids and suggest that retinoids and T- or NK-cell based immunotherapy can have mutually enhancing effects in UM patients.

Improved Immunogenicity of an Immunodominant Epitope of the Her-2/neu Protooncogene by Alterations of MHC Contact Residues

The HER-2/neu (HER-2) oncogene is expressed in normal epithelial surfaces at low levels and overexpressed in several types of tumors. The low immunogenicity against this self tumor Ag can be improved by developing epitopes with amino acid replacements in their sequences. In this study, three HER-2/neu.369 (HER-2.369) analogue peptides, produced by modifying both anchor positions by introducing L, V, or T at position 2 and V at the C terminus, were analyzed for their capacity to induce CTLs in vitro from human PBMC and in vivo in HLA-A2.1/Kb transgenic mice. One of the analogues (HER-2.369 V2V9) sensitized target cells for HER-2-specific recognition by human CTLs and induced specific CTLs in vitro at 100-fold lower concentrations than the HER-2.369 wild-type epitope. These CTLs were also able to recognize the wild-type epitope and HER-2-expressing tumors in an MHC-restricted manner. Furthermore, a 100-fold lower amount of the HER-2.369 V2V9 analogue compared with the wild-type epitope was required to induce CTLs in HLA-A2.1/Kb transgenic mice. However, the V2V9 analogue demonstrated only marginally better binding to the MHC class I A2 allele compared with wild type. To establish thermodynamic parameters, we developed radiolabeled F3*Y analogues from both the HER-2.369 epitope and the V2V9 analogue. Our results indicate that the high biological activity of the HER-2.369 V2V9 epitope is associated with a slower dissociation kinetic profile, resulting in an epitope with greater HLA-A2 stability.

Retinoids act as multistep modulators of the major histocompatibility class I presentation pathway and sensitize neuroblastomas to cytotoxic lymphocytes

The current therapeutic modalities achieve low response rates in human neuroblastoma, a frequent extracranial malignancy of the early childhood. We have assessed the effect of retinoids, used presently for the treatment of neuroblastoma, on the discrete steps of the MHC class I processing machinery and susceptibility of neuroblastoma cells to CTL-mediated killing. We demonstrate that retinoic acid derivatives induce the expression of proteolytic and regulatory subunits of the immunoproteasome, increase the half-life of MHC class I complexes, and enhance the sensitivity of neuroblastoma cells to both MHC class I-restricted peptide-specific and HLA nonrestricted lysis by CTLs. Importantly, effects of retinoids on the MHC class I pathway appear to be independent of IFN-gamma and/or TNF-alpha as intermediate messengers. To our knowledge, this is the first demonstration of inflammation-unrelated biological molecules that induce systemic modulation of antigen presentation in nonprofessional antigen presenting cells. Our findings suggest that the application of retinoids and T cell-based immunotherapy may be an effective combination for the treatment of neuroblastoma.

Determination of antioxidant efficacy of cosmetic formulations by non-invasive measurements

BACKGROUND/AIMS

Antioxidants have been proposed, over the last decade, as functional ingredients for anti aging preparations and to prevent and modulate oxidative skin damages. Up to date, beside the photo-induced oxidative skin damages model, none in vivo protocols have shown sufficient reproducibility for the validation of the antioxidant claim for a cosmetic finished product. To this aim, we have recently anticipated a new in vivo protocol based on a microinflammatory model, driven by reactive oxygen species. In the present study our model was validated by comparison with four different instrumental methods.

METHODS

The effects of a pre-treatment of two different formulations based on antioxidant functional ingredients, were investigated on forearm skin of 15 healthy volunteers, and compared to a cosmetic base and control area. The instruments considered in the study were Chromameter (CR-300 Minolta), Tewameter TM 210 (Courage-khazaka, Cologne, Germany), Laser Doppler Perfusion Imager (PIM1.0 Lisca Development AB, Sweden), in comparison to DermAnalyzer(R), an easy to use software program developed by us, using the CIE L*a*b* color space parameters.

RESULTS

The comparative measurements showed that the antioxidant formulations tested were all able to reduce, in different but statistically significant extent, the intensity of skin redness, and of cutaneous blood flow, when compared to control area (P < 0.0001).

CONCLUSIONS

The methyl nicotinate (MN) based microinflammatory model, in conjunction with objective measure- ments, resulted an effective tool for in vivo assessment of oxidative skin injuries. In view of the high level of repeatability, short time of answer and simplicity, the procedure by us developed, is proposed as a possible protocol for the evaluation of in vivo efficacy of antioxidant functional ingredients in cosmetic formulations.

Proteasome inhibitors reconstitute the presentation of cytotoxic T-cell epitopes in Epstein-Barr virus-associated tumors

EBV-infected cells and EBV-associated tumors may evade CTL recognition by defective antigen processing, resulting in poor presentation of CTL epitopes. Since the proteasome is the major source of MHC class I-presented peptides, we analyzed the effect of proteasome inhibitors on the expression of surface HLA class I and the generation of EBV-derived CTL epitopes presented by the HLA-A2 and HLA-A11 alleles. Treatment with covalent and reversible inhibitors of the proteasome partially reduced the total and allele-specific expression of surface HLA class I in EBV-carrying LCLs. HLA-A2 expression was also decreased by treatment with leupeptin and bestatin, while HLA-A11 expression was affected by treatment with phenanthroline. Despite their general inhibitory effect on HLA class I expression, all proteasome inhibitors tested enhanced the presentation of 2 subdominant HLA-A2 epitopes from EBV LMP1 and LMP2, while the presentation of the immunodominant HLA-A11-restricted epitope from EBNA4 was inhibited by MG132 and lactacystin and increased by ZL(3)VS. Treatment with ZL(3)VS restored the presentation of endogenously expressed EBNA4 in 1 HLA-A11-positive BL cell line. These findings suggest that specific inhibitors of the proteasome may be used to increase the antigenicity of virus-infected and malignant cells that are per se inefficient at generating particular CTL target epitopes.

Effect of interferon-alpha therapy on epitope-specific cytotoxic T lymphocyte responses in hepatitis C virus-infected individuals

The majority of hepatitis C virus (HCV)-infected individuals fail to resolve the infection and become chronically infected despite the presence of HCV-specific CTL responses directed to different HCV-derived peptide antigens. Only a minority of individuals is able to clear the virus by mounting efficient CTL responses early after acute infection, but at present it is not clear whether viral clearance is associated with CTL responses of defined specificity. To elucidate those responses associated with improvement of the disease, we analyzed CTL responses to 16 different HLA-A2-presented, HCV-derived epitopes in 12 chronically infected patients, 14 chronically infected patients treated with interferon-alpha, and in one patient with acute symptomatic disease. We show here that the majority of chronically infected individuals present CTL responses directed to an NS4-derived peptide antigen (amino acids 1789-1797). Treated patients presented stronger HCV-specific CTL responses and therapy-induced changes in CTL target choice. In particular, 13 out of 14 individuals responded to an NS3-derived epitope (amino acids 1073-1081). By longitudinal analysis we show that five individuals responding to IFN-alpha therapy with decreases in alanine aminotransferase levels presented a strong CTL activity directed to the NS3-derived epitope. One patient that spontaneously resolved the infection presented a generally strong CTL activity specific for HCV-derived epitopes with a dominant response to the NS3-derived peptide antigen. This suggests that CTL responses directed to this NS3-derived antigen may be beneficial for the control of HCV infection. Improvement of these responses may represent a therapeutic intervention in chronic HCV infection.

Effect of interferon-alpha therapy on epitope-specific cytotoxic T lymphocyte responses in hepatitis C virus-infected individuals

The majority of hepatitis C virus (HCV)-infected individuals fail to resolve the infection and become chronically infected despite the presence of HCV-specific CTL responses directed to different HCV-derived peptide antigens. Only a minority of individuals is able to clear the virus by mounting efficient CTL responses early after acute infection, but at present it is not clear whether viral clearance is associated with CTL responses of defined specificity. To elucidate those responses associated with improvement of the disease, we analyzed CTL responses to 16 different HLA-A2-presented, HCV-derived epitopes in 12 chronically infected patients, 14 chronically infected patients treated with interferon-alpha, and in one patient with acute symptomatic disease. We show here that the majority of chronically infected individuals present CTL responses directed to an NS4-derived peptide antigen (amino acids 1789-1797). Treated patients presented stronger HCV-specific CTL responses and therapy-induced changes in CTL target choice. In particular, 13 out of 14 individuals responded to an NS3-derived epitope (amino acids 1073-1081). By longitudinal analysis we show that five individuals responding to IFN-alpha therapy with decreases in alanine aminotransferase levels presented a strong CTL activity directed to the NS3-derived epitope. One patient that spontaneously resolved the infection presented a generally strong CTL activity specific for HCV-derived epitopes with a dominant response to the NS3-derived peptide antigen. This suggests that CTL responses directed to this NS3-derived antigen may be beneficial for the control of HCV infection. Improvement of these responses may represent a therapeutic intervention in chronic HCV infection.

Effect of interferon-alpha therapy on epitope-specific cytotoxic T lymphocyte responses in hepatitis C virus-infected individuals

The majority of hepatitis C virus (HCV)-infected individuals fail to resolve the infection and become chronically infected despite the presence of HCV-specific CTL responses directed to different HCV-derived peptide antigens. Only a minority of individuals is able to clear the virus by mounting efficient CTL responses early after acute infection, but at present it is not clear whether viral clearance is associated with CTL responses of defined specificity. To elucidate those responses associated with improvement of the disease, we analyzed CTL responses to 16 different HLA-A2-presented, HCV-derived epitopes in 12 chronically infected patients, 14 chronically infected patients treated with interferon-alpha, and in one patient with acute symptomatic disease. We show here that the majority of chronically infected individuals present CTL responses directed to an NS4-derived peptide antigen (amino acids 1789-1797). Treated patients presented stronger HCV-specific CTL responses and therapy-induced changes in CTL target choice. In particular, 13 out of 14 individuals responded to an NS3-derived epitope (amino acids 1073-1081). By longitudinal analysis we show that five individuals responding to IFN-alpha therapy with decreases in alanine aminotransferase levels presented a strong CTL activity directed to the NS3-derived epitope. One patient that spontaneously resolved the infection presented a generally strong CTL activity specific for HCV-derived epitopes with a dominant response to the NS3-derived peptide antigen. This suggests that CTL responses directed to this NS3-derived antigen may be beneficial for the control of HCV infection. Improvement of these responses may represent a therapeutic intervention in chronic HCV infection.

Design, synthesis and enzymatic activity of highly selective human mitochondrial thymidine kinase inhibitors

Highly selective arabinofuranosyl nucleosides, which inhibit the mitochondrial thymidine kinase (TK-2) without affecting the closely related herpes simplex virus type 1 thymidine kinase (HSV-1 TK), varicella-zoster virus thymidine kinase (VZV-TK), cytosolic thymidine kinase (TK-1) or the multifunctional Drosophila melanogaster deoxyribonucleoside kinase (Dm-dNK), have been obtained. SAR studies indicate a close relation between the length of the substituent at the 2' position of the arabinofuranosyl moiety and the inhibitory activity.

c-myc overexpression activates alternative pathways for intracellular proteolysis in lymphoma cells

Burkitt's lymphoma (BL) is a highly malignant B-cell tumour characterized by chromosomal translocations that constitutively activate the c-myc oncogene. Here we show that BL cells are resistant to apoptosis and do not accumulate ubiquitin conjugates in response to otherwise toxic doses of inhibitors of the proteasome. Deubiquitinating enzymes and the cytosolic subtilisin-like protease tripeptidylpeptidase II are upregulated in BLs, and could be rapidly induced by the overexpression of c-myc in normal B cells carrying oestrogen-driven recombinant Epstein-Barr virus. Apoptosis was induced by inhibiting tripeptidylpeptidase II, suggesting that the activity of this protease may be required for the survival of BL cells. We thus show that there is a regulatory link between c-myc activation and changes in proteolysis that may affect malignant transformation.

Novel antioxidant agents deriving from molecular combinations of vitamins C and E analogues: 3,4-dihydroxy-5(R)

Molecular combinations of two antioxidants (i.e., ascorbic acid and the pharmacophore of alpha-tocopherol), namely the 2,3-dihydroxy-2,3-enono-1,4-lactone and the chromane residues, have been designed and tested for their radical scavenging activities. When evaluated for their capability to inhibit malondialdehyde (MDA) production in rat liver microsomal membranes, the 3,4-dihydroxy-5R-2(R,S)-(6-hydroxy-2,5,7,8-tetramethylchroman-2(R,S)yl-methyl)-1,3]dioxolan-4S-yl]-5H-furan-2-one (11a-d), exhibited an interesting activity. In particular the 5R,2R,2R,4S and 5R,2R,2S,4S isomers (11c,d) displayed a potent antioxidant effect compared to the respective synthetic alpha-tocopherol analogue (5) and natural alpha-tocopherol or ascorbic acid, used alone or in combination. Moreover, the mixture of stereoisomers 11a-d also proved to be effective in preventing damage induced by reperfusion on isolated rabbit heart, in particular at the higher concentration of 300 microM. In view of these results our study represents a new approach to potential therapeutic agents for applications in pathological events in which a free radical damage is involved. Design, synthesis and preliminary biological activity are discussed.

Supra-agonist peptides enhance the reactivation of memory CTL responses

Single amino acid substitutions at TCR contacts may transform a natural peptide Ag in CTL ligands with partial agonist, antagonist, or null activity. We obtained peptide variants by changing nonanchor amino acid residues involved in MHC class I binding. These peptides were derived from a subdominant HLA-A2-presented, latent membrane protein 2-derived epitope expressed in EBV-infected cells and in EBV-associated tumors. We found that small structural changes produced ligands with vastly different activities. In particular, the variants that associated more stably to HLA-A2/molecules did not activate any CTL function, behaving as null ligands. Interestingly, T cell stimulations performed with the combination of null ligands and the natural epitope produced significantly higher specific CTL reactivation than reactivation of CTLs induced by the wild-type epitope alone. In addition, these particular variants activated memory CTL responses in the presence of concentrations of natural epitope that per se did not induce T cell responses. We show here that null ligands increased ZAP-70 tyrosine kinase activation induced by the natural epitope. Our results demonstrate for the first time that particular peptide variants, apparently behaving as null ligands, interact with the TCR, showing a supra-agonist activity. These variant peptides did not affect the effector T cell functions activated by the natural epitope. Supra-agonist peptides represent the counterpart of antagonists and may have important applications in the development of therapeutic peptides.

Design, synthesis and binding at cloned muscarinic receptors of N-[5-(1'-substituted-acetoxymethyl)-3-oxadiazolyl] and N-[4-(1'-substituted-acetoxymethyl)-2-dioxolanyl] dialkyl amines

Few muscarinic antagonists differentiate between the M4 and M2 muscarinic receptors. In a structure activity study, aimed at discovering leads for the development of a M4 muscarinic receptor-selective antagonist, we have synthesized and tested at cloned muscarinic receptors the binding of a group of dioxolane- or oxadiazole-dialkyl amines, and compared them to our compound 1, which contains the furan nucleus. Although none of these agents were particularly potent at M4 receptors (Kd values were typically 30-70 nM), furan derivatives (-)1 and (+)1 were significantly more potent at M4 receptors than at M2 receptors (approximately 3- and 4-fold, respectively). The dioxolane derivatives 12b and 12c were more than 10-fold selective for the M4 versus the M2 receptors, while the dioxolane derivative 12e was 15-fold more potent at M4 receptors than for M2 receptors. However, these agents bound to M3 receptors with potencies like that for the M4 receptor, so they are not M4-selective. The M4/M2 relative selectivities of some of our compounds are similar to the better hexahydrosiladifenidol derivatives, and may provide some important structural clues for the development of potent and selective M4 antagonists.

Pyrazole related nucleosides 5. Synthesis and biological activity of 2'-deoxy-2',3'-dideoxy- and acyclo-analogues of 4-iodo-1-beta-D-ribofuranosyl-3-carboxymethyl pyrazole (IPCAR)

Continuing our studies on the structure-activity relationships (SAR) of 4-iodo-1-beta-D-ribofuranosyl-3-carboxymethyl pyrazole (IPCAR), the ribofuranosyl moiety has been substituted with acyclic chains, namely 1-[(2-hydroxyethoxy)methyl]- and 1-[(1,3-dihydroxy-2-propoxy)methyl]-pyrazole derivatives (4, 5 and 8, 9 respectively), with the 2'-deoxy-beta-D-ribofuranosyl group (12 and 13) and finally with the 2',3'-dideoxy-D-glycero-pentofuranosyl-moiety (16 and 17). None of the new compounds display any interesting biological activity.

5'-Phosphoramidates and 5'-diphosphates of 2'-O-allyl-beta-D-arabinofuranosyluracil, -cytosine, and -adenine: inhibition of ribonucleotide reductase

Continuing our studies on ribonucleotide reductase (RNR) mechanism-based inhibitors, we have now prepared the diphosphates (DP) of 2'-O-allyl-1-beta-D-arabinofuranosyl-uracil and -cytosine and 2'-O-allyl-9-beta-D-arabinofuranosyl-adenine and evaluated their inhibitory activity against recombinant murine RNR. 2'-O-Allyl-araUDP proved to be inhibitory to RNR at an IC(50) of 100 microM, whereas 2'-O-allyl-araCDP was only marginally active (IC(50) 1 mM) and 2'-O-allyl-araADP was completely inactive. The susceptibility of the parent nucleosides to phosphorylation by thymidine kinase and 2'-deoxycytidine kinase was also investigated, and all nucleosides proved to be poor substrates for the above-cited kinases. Moreover, prodrugs of 2'-O-allyl-araU and -araC monophosphates, namely 2'-O-allyl-5'-(phenylethoxy-L-alanyl phosphate)-araU and -araC, were prepared and tested against tumor cell proliferation but proved to be inactive. A molecular modeling study has been conducted in order to explain our results. The data confirm that for both the natural and analogue nucleoside diphosphates, the principal determinant interaction with the active site of RNR is with the diphosphate group, which forms strong hydrogen bonds with Glu623, Thr624, Ser625, and Thr209. Our findings indicate that the poor phosphorylation may represent an explanation for the lack of marked in vitro cytostatic activity of the test compounds.

Enzymatic synthesis of 2'-O-acyl prodrugs of 1-(beta-D-arabinofuranosyl)-5(E)-(2-bromovinyl)uracil and of 2'-O-acyl-araU, -araC and -araA

Pig liver esterase (EC 3.1.1.1) catalysed regioselective hydrolysis of 1-(2,3,5-tri-O-acyl-beta-D-arabinofuranosyl)uracil, -cytosine and -adenine to give the corresponding 2'-monoesters effectively and in high yield. This methodology enabled the preparation of 1-(2-O-acyl-beta-D-arabinofuranosyl)-5-[(E)-(2-bromovinyl)]uracil prodrugs which, although slightly less active than the parent 1-(beta-D-arabinofuranosyl)-5-(E)-(2 bromovinyl)uracil (sorivudine; BV-araU), were strongly active in vitro against varicella-zoster virus (ED50 2.4-45 ng/ml). The retarded rates of enzymatic hydrolysis of the 2'-esters imply that they might function as lipophilic prodrugs, leading to increased plasma and cellular concentrations. In view of the marked in vitro activity, they represent an interesting approach to arabinofuranosyl nucleoside prodrugs with improved pharmacokinetics and enzymatic stability.

Retinoic acid conjugates as potential antitumor agents: synthesis and biological activity of conjugates with Ara-A, Ara-C, 3(2H)-furanone, and aniline mustard moieties

In a dual targeting approach, to explore the ability of tretinoin (all-trans-retinoic acid) to behave as a covalent carrier for cytotoxic entities, conjugates of retinoic acid with a few representative molecules, being important examples of antitumor pharmacophores (i.e., nucleoside analogues and alkylating agents), have been synthesized and tested for their cytostatic and differentiating activity. All compounds were stable to in vitro hydrolysis in human plasma and more lipophilic than the parent compounds, thus consenting enhanced uptake into the cells. Among the nucleoside analogues the Ara-C derivatives 3 and 6 and the Ara-A derivative 7 proved the most cytostatic (IC50 < 0.32 microgram/mL) resulting from 25- to > 144-fold more active (Ara-A derivatives) or at least as equally active (Ara-C derivatives) as compared to the parent nucleosides. Compound 3, endowed with a highly lipophilic silyl moiety at the 3' and 5' positions, showed the highest differentiating activity (54% and 44% differentiated HL-60 cells at 0.2 and 0.05 microgram/mL respectively). With regard to the retinoic acid conjugates of alkylating agents, compound 10 was the most cytostatic agent (IC50 < 0.32 microgram/mL) and the most potent differentiating agent (33-34% at 0.32 and 0.08 microgram/mL). These structures may also be regarded as analogs of either retinoic acid or the cytotoxic compound.