Dried Blood and Serum Spots As A Useful Tool for Sample Storage to Evaluate Cancer Biomarkers.

Blood sample quality is crucial to ensure accurate downstream analyses such as real-time PCR or ELISA. Correct storage of biological materials is the starting point to achieve reproducible and reliable results. All samples should be treated in the same way from blood collection to storage. Depending on the analyses to be performed, whole blood and serum samples should be stored at -20 °C or -80 °C until use. Blood/serum samples should also be aliquoted to avoid multiple freeze-thawing. Another important issue is the sample conditions during shipment from one laboratory to another. If dry ice is not available or the shipment takes longer than a few days, alternative approaches are needed. One option is to use filter paper for blood collection. Here, we propose a method for blood and serum sample collection that takes advantage of dried blood spots (DBS) and dried serum spots (DSS). We developed the procedure to extract DNA from DBS for the downstream evaluation of some single nucleotide polymorphisms (SNPs) by real time PCR. We also optimized an ELISA assay starting from proteins eluted from DSS. This method can be used with other ELISA assays or procedures evaluating proteins.

Are There Differences in Androgen Receptor Expression in Invasive Breast Cancer in African (Tanzanian) Population in Comparison With the Caucasian (Italian) Population?

PURPOSE: Androgen receptor (AR) has been shown to have prognostic implication on breast cancer (BC). Data on the biological features of African BCs are poor. We decided for the first time to compare AR expression of Tanzanian and Italian BC patients. PATIENTS AND METHODS: Of the 69 consecutive patients seen at the Bugando Medical Center (Mwanza, Tanzania) from 2003 to 2010, who underwent resection of primary BC evaluable for estrogen receptor, progesterone receptor (PgR), and HER2 only 65 were evaluable for AR by immunohistochemistry. Histopathological assessment and biomolecular determinations were performed at the Cancer Institute of Romagna [Istituto Scientifico Romagnolo per lo studio e la cura dei tumori (IRST)-IRCCS, Meldola, Italy]. Caucasian BC patients were selected from an electronic database and matched (1:2 ratio) for year of diagnosis and age at diagnosis. RESULTS: The median age of patients at diagnosis was 51 (range 29-83) years for Tanzanian and 53 (range 26-86) years for Italian patients. Tanzanian patients harbored tumors with lower AR expression than Italian patients according to the median percentage of immunopositive tumor cells (30% versus 80%, p < 0.0001) and staining intensity (p = 0.0003). The proportion of AR negative patients was likewise higher among Tanzanian patients as regards both ≥1% and ≥10% cutoffs. AR-positive BCs were higher in luminal A and B tumors and decreased in triple-negative (TN) and HER2-enriched tumors in Tanzanian population. CONCLUSION: AR loss could represent an unfavorable prognostic marker in the African population. The high frequency of TN tumors with high AR expression could open new perspectives of therapy for population in this low income country.

Vitamin D receptor polymorphisms or serum levels as key drivers of breast cancer development? The question of the vitamin D pathway.

As total vitamin D levels are often lower in black than in white Americans, the former are frequently classified as vitamin D-deficient. To fully understand African vitamin D (25(OH)D) status, other factors should be considered, e.g. vitamin D blood carrier, vitamin D-binding protein (DBP), vitamin D receptor (VDR) and DBP polymorphisms. A prospective study on an indigenous black Tanzanian and a Caucasian Italian population was performed on 50 healthy donors from both populations and 35 Caucasian and 18 African breast cancer patients. 25(OH)D and DBP serum levels were analyzed by ELISA. A1012G, Cdx2 and Fok1 VDR polymorphisms and DBP polymorphisms rs4588 and rs7041 were genotyped by real-time PCR. Vitamin D and DBP levels were lower in healthy African donors than in Caucasians. Africans had a significantly higher frequency of AA and CC for Cdx2 and Fok1 polymorphisms, respectively. These allelic variants were related to a higher transcription of VDR gene and a higher activity of VDR receptor. With regard to polymorphism distribution, Africans showed innate higher levels and activity of VDR. We conclude that a strengthening of the vitamin D pathway could have a protective role against the development of breast cancer in the African population.