Genotype and Phenotype Characterization of Patients with Mucopolysaccharidosis IV-A in Chile

Introduction

Morquio syndrome or mucopolysaccharidosis type IV-A (MPS IV-A) is an autosomal recessive disease caused by biallelic variants in the GALNS gene, encoding the lysosomal enzyme GalN6S, responsible for glycosaminoglycan keratan sulfate and chondroitin-6-sulfate degradation. Studies have shown that the degree of evolutionary and chemical divergence of missense variants in GalN6S when compared to ancestral amino acids is associated with the severity of the syndrome, suggesting a genotype-phenotype correlation. There is little information on Latin American patients with MPS IV-A that replicate these findings. This study aimed to characterize the phenotype and genotype from patients with MPS IV-A, who are under Enzyme Replacement Therapy at the Children's Neuropsychiatry Service of the Hospital Clínico San Borja Arriarán, Santiago, Chile, and to determine if there is any association between genotype and phenotype with those findings.

Methods

Information was collected from medical charts, all patients went through a GalN6S enzymatic activity measurement in leukocytes from peripheral blood, and the GALNS gene was sequenced for all cases.

Results

12 patients with MPS IV-A were recruited, all patients presented multisystem involvement, mostly skeletal, and 75% of cases underwent surgical interventions, and cervical arthrodesis was the most frequent procedure. In regards of the genotype, the two most frequent variants were c.319+2T>C (n = 10, 41.66%) and p.(Arg386Cys) (n = 8, 33.33%), the first one was previously described in 2018 in a patient from Chile [Bochernitsan et al., 2018].

Conclusion

This is the first time that a genotype-phenotype correlation has been studied by analyzing the variants effect on the molecular structure of human GalN6S and the evolutionary conservation degree of affected residues in a cohort of patients in Chile. Albeit our work could not find statistically significant associations, we may infer that the evolutionary conservations of affected amino acids and the effect of variants on enzyme structure may play a main role. Further analyzes should consider a meta-analysis of published cases with genotype data and larger samples and include other variables that could provide more information. Finally, our data strongly suggest that variant c.319+2T>C could have a founder effect in Chilean patients with MPS IV-A.

Toxicity and antitumor activity of novel agents in elderly patients with cancer included in phase 1 studies

Introduction The number of cancer cases among the elderly continue to increase as the worldwide population ages. This patient subset is underrepresented in clinical trials, partly because of unresolved uncertainties about age-associated tolerabilities and antitumor activities. We reviewed phase 1 trial data to study tolerance and efficacy of novel agents used for treatment of elderly patients with cancer. Methods Data from 773 consecutive evaluable patients in 85 phase 1 clinical trials (2008-2016) at START Madrid-CIOCC were analyzed according to age, with respect to objective response, survival, and toxicity. Results The mean age was 58.7 (range: 18-87) years; 260 (33.6%) patients were >65 y (elderly group). One hundred thirty-seven (17.8%) patients received immunotherapy drugs, 308 (39.8%) received targeted agents, and 328 (42.4%) received chemotherapy. No statistically significant differences in overall survival, objective response, or severe toxicity rates were found according to treatment type. Similar toxicities and clinical activities were found between the two age subgroups; 18.8% of the elderly and 20.7% of the younger patients experienced severe hematological toxicity (p=0.5), and 30.2% and 32.7%, respectively, experienced severe non-hematological toxicity (p=0.4). Regarding antitumor activity, 12.4% of the elderly and 15% of the younger patients achieved objective responses (p=0.41). There were no significant between-group differences in overall survival (9.7 versus 11.5 months, respectively, p=0.1) or progression-free survival (2.3 versus 2.2 months, respectively, p=0.7). Conclusions This retrospective study found that elderly and younger populations had comparable antitumor activities and toxicity profiles. These results support including elderly patients with cancer in early-phase trials.

Phylogeographic and genome-wide investigations of Vietnam ethnic groups reveal signatures of complex historical demographic movements

The territory of present-day Vietnam was the cradle of one of the world’s earliest civilizations, and one of the first world regions to develop agriculture. We analyzed the mitochondrial DNA (mtDNA) complete control region of six ethnic groups and the mitogenomes from Vietnamese in The 1000 Genomes Project (1000G). Genome-wide data from 1000G (~55k SNPs) were also investigated to explore different demographic scenarios. All Vietnamese carry South East Asian (SEA) haplotypes, which show a moderate geographic and ethnic stratification, with the Mong constituting the most distinctive group. Two new mtDNA clades (M7b1a1f1 and F1f1) point to historical gene flow between the Vietnamese and other neighboring countries. Bayesian-based inferences indicate a time-deep and continuous population growth of Vietnamese, although with some exceptions. The dramatic population decrease experienced by the Cham 700 years ago (ya) fits well with the Nam tiến (“southern expansion”) southwards from their original heartland in the Red River Delta. Autosomal SNPs consistently point to important historical gene flow within mainland SEA, and add support to a main admixture event occurring between Chinese and a southern Asian ancestral composite (mainly represented by the Malay). This admixture event occurred ~800 ya, again coinciding with the Nam tiến.

Abstract P4-03-16: FAPα (fibroblast activation protein-α) analysis in breast tumor cells and stroma after neoadjuvant treatment

Background: FAPα is a transmembrane serine protease expressed on cancer associated fibroblast that promotes tumour growth and invasion. In patients (pts) with poor outcome and survival FAPα is highly overexpressed. FAPα is also expressed in stroma across all breast cancer subtypes without association with clinicopathological factors. Pts without Complete Pathological Response (pCR) after Neoadjuvant Chemotherapy (NC) had poor outcome. We analysed the relationship between the expression of FAPα in stroma (fibroblast) and in epithelial breast cancer cells of pts without pCR after NC (taxanes, antracyclines and trastuzumab in Her2+).

Methods: 60 pts were included. ER, PR and Ki67 were studied by IHQ (Ventana) and Her2 by FISH (PatnVysion). FAPα expression was determined by IHQ (polyclonal, Ventana). St Gallen guidelines for subtype of breast cancer were used.

Results: 53 pts had tissue. Median age 47 years (range 29-68). Median tumour size 43mm and 10 (18.9%) were multifocal. 37 (69.8%) had positive axillary nodes. 47 were ductal invasive carcinomas. 33 (62.3%) were grade 2 and 20 (37.7%) grade 3. 44 pts (83%) had ER+ (20 luminal B), 17 (32%) Her2+ and 6 (11%) triple negative(TN). Median Ki67 was 22% (p25-75:15-38%). Miller-Payne response was 1.9% G1 (1pt), 43.4% G2 (23 pts), 41.5% G3 (22 pts) and 13.2% G4 (7 pts). The recurrences were 2 local and 12 distant (26.4%). Median FAPα in residual epithelial breast cancer cells after NC was 85% (p25-75:30-95%) and in the stroma 20% (p25-75:10-62%). Median epithelial FAPα was 55% in TN, 85% Her2, 72.5% luminal A and 92.5% in luminal B. Median stromal FAPα was 52.5% in TN, 20% Her2, 15% luminal A and 15% in luminal B. There is not association between stromal FAPα and clinicopathological features, but a higher epithelial FAPα was found in tumours wih higher ER, PR and Ki67. In luminal B subtype, stromal FAPα was smaller in pts with relapses (median 7.5%) than without relapses (median 30%). Conclusions: Stromal FAPα in residual cancer after NC is higher in TN breast cancer but without association with relapses in our small sample. However, in luminal B subtype stromal FAPα is smaller in pts with relapses.

Citation Format: Calvo I, Prieto M, Suárez-Gauthier A, Pérez FJ, Hernández E, Acosta D, Cárdenas JM, López-Ríos F, Estévez LG. FAPα (fibroblast activation protein-α) analysis in breast tumor cells and stroma after neoadjuvant treatment [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-03-16.

Loss of Nm23 is associated with a more favorable tumor microenvironment in patients with breast cancer

AIM

Nm23 is a metastasis suppressor gene whose downregulation triggers metastatic progression. The aim of this study was to investigate the expression of Nm23 in breast carcinomas and its relationship with tumor microenvironment markers.

METHODS

A retrospective study was done (128 breast cancer patients from 2007 to 2010). Nm23, LPA1, SMA, CD34, CD8, and CD68 protein expressions were evaluated using immunohistochemistry. Image analysis was used to determine the immunostaining percentage area of Nm23, LPA1, and SMA; the number of the total vessel fraction CD34 positive; and the number of CD8+ and CD68+ cells. The mean ± SE was calculated. The differences among groups were evaluated using Student t-test for parametric data and Mann Whitney U test for nonparametric data.

RESULTS

Cases were divided into two groups: Nm23+ and Nm23-. LPA1 immunostaining was significantly increased in Nm23- group. Immunostaining percentage area of SMA was not significantly higher when Nm23 was negative. CD34 immunopositive blood vessels, number of T CD8+ cells, and the number of macrophage CD68+ cells were increased when Nm23 was absent.

CONCLUSION

Our results suggest that the absence of Nm23 causes an increase in LPA1, CD8+ and CD68+ inflammatory cells, and angiogenesis marker. Therefore, Nm23 loss could be associated with a more favorable environment for the development and dissemination of breast cancer. However, more studies are needed to determine this association.

Comparative analysis of national regulations concerning blood safety across Europe

In October 2001, representatives of 17 European countries (Albania, Bosnia-Herzegovina, Bulgaria, Croatia, Czech Republic, Federal Republic of Yugoslavia, Finland, France, Germany, Greece, Italy, Macedonia, Romania, Slovenia, Spain, Turkey and UK) met in Sarajevo at a course organized by the European School of Transfusion Medicine to discuss their countries' regulations concerning different aspects of the safety of blood transfusion. Results are summarized in tables to facilitate comparisons. Most countries (13/17) have specific transfusion laws and 9/17 have hospital-based systems as opposed to national organizations. Quality assurance is common among investigated countries (14/17). Voluntary associations are responsible for donor promotion in the majority of countries (13/17). Exclusively, voluntary non-remunerated donors are found in 5/17 countries, whereas in the remaining ones, incentives, family replacement and remuneration are mechanisms stimulating blood donation. Medical doctors using official selection criteria are checking donor suitability in virtually all countries, which also perform main microbiological testing. Regulations on good clinical use of blood and derivatives are present in most countries but applied only in some. Although the data presented need to be interpreted with some caution, this preliminary analysis shows that, although some significant differences still exist, the majority of countries studied are moving in the same direction to ensure safety of their blood supply.