The relationship between the aggrecan VNTR polymorphism and its content in lumbar intervertebral discs

BACKGROUND

There is a specific polymorphism of the ACAN gene called the VNTR (variable number of tandem repeats), which is particularly interesting in the light of the development of intervertebral disc pathology and associated low back pain.

MATERIALS AND METHODS

The nucleus pulposus specimens were harvested from the L5/S1 intervertebral discs. The aggrecan content was determined using enzyme-linked immunosorbent assay (ELISA). Moreover, the VNTR polymorphism in the ACAN gene was evaluated.

RESULTS

The genotyping of VNTR polymorphism in ACAN gene was successful in 94 tissue samples (48 homozygotes and 46 heterozygotes). The alleles were divided into four groups, in accordance with the number of tandem repeats in the ACAN gene. No difference between groups in the mean aggrecan mass nor in the mean degree of tissue moisture was observed.

CONCLUSIONS

No relationship between the ACAN gene VNTR polymorphism and the aggrecan content was observed in studied Caucasian cadavers. Such a relationship may be a more complex phenomenon and exists in other populations.

From carotenoid intake to carotenoid blood and tissue concentrations - implications for dietary intake recommendations

There is uncertainty regarding carotenoid intake recommendations, because positive and negative health effects have been found or are correlated with carotenoid intake and tissue levels (including blood, adipose tissue, and the macula), depending on the type of study (epidemiological vs intervention), the dose (physiological vs supraphysiological) and the matrix (foods vs supplements, isolated or used in combination). All these factors, combined with interindividual response variations (eg, depending on age, sex, disease state, genetic makeup), make the relationship between carotenoid intake and their blood/tissue concentrations often unclear and highly variable. Although blood total carotenoid concentrations <1000 nmol/L have been related to increased chronic disease risk, no dietary reference intakes (DRIs) exist. Although high total plasma/serum carotenoid concentrations of up to 7500 nmol/L are achievable after supplementation, a plateauing effect for higher doses and prolonged intake is apparent. In this review and position paper, the current knowledge on carotenoids in serum/plasma and tissues and their relationship to dietary intake and health status is summarized with the aim of proposing suggestions for a "normal," safe, and desirable range of concentrations that presumably are beneficial for health. Existing recommendations are likewise evaluated and practical dietary suggestions are included.

Critical Roles of EGFR Family Members in Breast Cancer and Breast Cancer Stem Cells: Targets for Therapy

The roles of the epidermal growth factor receptor (EGFR) signaling pathway in various cancers including breast, bladder, brain, colorectal, esophageal, gastric, head and neck, hepatocellular, lung, neuroblastoma, ovarian, pancreatic, prostate, renal and other cancers have been keenly investigated since the 1980's. While the receptors and many downstream signaling molecules have been identified and characterized, there is still much to learn about this pathway and how its deregulation can lead to cancer and how it may be differentially regulated in various cell types. Multiple inhibitors to EGFR family members have been developed and many are in clinical use. Current research often focuses on their roles and other associated pathways in cancer stem cells (CSCs), identifying sites where therapeutic resistance may develop and the mechanisms by which microRNAs (miRs) and other RNAs regulate this pathway. This review will focus on recent advances in these fields with a specific focus on breast cancer and breast CSCs. Relatively novel areas of investigation, such as treatments for other diseases (e.g., diabetes, metabolism, and intestinal parasites), have provided new information about therapeutic resistance and CSCs.

Increased Akt signaling resulting from the loss of androgen responsiveness in prostate cancer

The mechanisms responsible for the switch of prostate cancer from androgen-sensitive (AS) to androgen-insensitive (AI) form are not well understood. Regulation of androgen receptor (AR), through which androgens control the expression of genes involved in prostate cells proliferation, migration and death also involves its cross-talk with the other signaling pathways, transcription factors and coregulatory proteins, such as β-catenin. With the aim to determine their possible contribution in triggering the switch from AS to AI form, which occurs upon androgen deprivation therapy - AR, Akt and β-catenin expression were knocked-down with respective siRNAs. Treatment of LNCaP prostate cells with siRNA for AR significantly reduced their proliferation (45-70%), expression of nuclear β- catenin, cyclin-D1, cyclin-G1, c-Myc as well as activity of metalloproteinases (MMPs) -2,-7,-9 and cell migration. Surprisingly, after longer (over 72 hrs) silencing of AR in LNCaP cells, elevated levels of p-Akt were detected and enhanced proliferation as well as expression of nuclear β-catenin, cyclin-D1, c-Myc and activity of MMPs were observed. Such effects were not observed in either PC-3 or DU145 AI cells. However, silencing of Akt and /or β-catenin in those as well as in LNCaP cells led to their decreased proliferation and migration. Our findings suggest that in prostate cancer cells, either AR or Akt signaling prevails, depending on their initial androgen sensitivity and its availability. In AI prostate cancer cells, Akt takes over the role of AR and more effectively contributes through the same signaling molecule, β-catenin, to AI cancer progression.

Expression of vascular endothelial growth factors VEGF- C and D, VEGFR-3, and comparison of lymphatic vessels density labeled with D2-40 antibodies as a prognostic factors in vulvar intraepithelial neoplasia (VIN) and invasive vulvar cancer

OBJECTIVE

The aim of this study was to compare the immunohistochemical expression of vascular endothelial growth factors VEGF-C and D, as well as the expression of VEGFR-3 in VIN and vulvar invasive cancer and to compare the density of lymphatic marker D2-40 antibody in both groups, and to compare them with different clinicopathologic features.

MATERIALS & METHODS

The study was performed using tissue material and clinical data from 100 women diagnosed with VIN and 100 women diagnosed with invasive vulvar cancer.

RESULTS

No significant differences were found in the expression of VEGF-C and -D or VEGFR-3 between those patients with VIN and those with invasive vulvar cancers. Weak expression of VEGF-C was confirmed only in two cases of the analyzed series; in all cases, expression of VEGF-D and VEGFR-3 was observed. The strongest expression of VEGF-D and VEGFR-3 was observed in the group of invasive cancers. The highest density of lymphatic vessels per 2 mm was observed in VIN. In the cancer group, small lymphatic vessels with a narrow oval lumen were observed. Moreover, in two cases of vulvar cancer, the presence of intratumoral lymphatic vessels was observed.

CONCLUSIONS

These results suggest that lymphangiogenesis begins at the preinvasive stage of vulvar carcinogenesis and suggests the important role of VEGF-C, VEGF-D, VEGFR-3 and LV (D2-40) as prognostic factors in the process of carcinogenesis in the vulvar area.

Expression of VEGF, VEGF-C and VEGFR-2 in in situ and invasive SCC of cervix

Cervical squamous cell carcinoma (SCC) arises from the metaplastic epithelium and develops slowly through dysplastic changes (i.e., cervical intraepithelial neoplasia--CIN) to carcinoma in situ and invasive cancer. There is little data concerning the quantitation of vascular endothelial growth factor (VEGF) and its correlation to the clinical or pathologic characteristics of SCC. This study assessed the expression of VEGF, VEGF-C and their receptor VEGFR-2 in 35 samples of normal cervical tissue, 35--CIN1, 35--CIN2 (25 non-pregnant, 15 pregnant women), 35--CIN3 and 30- SCC. VEGF, VEGF-C and VEGFR-2 were analyzed using RT-PCR, RQ-PCR, immunohistochemical staining and Western blot. VEGF, VEGF-C and VEGFR-2 were not detected in normal cervical epithelium. In CIN and SCC, both forms of VEGF and its receptor were identified, indicating a correlation between the increasing expression and staging of carcinoma. Results show the important role of VEGF in cervical progression and that the switch to the lymphangiogenesis phenotype occurs prior to the stage of invasion likely at CIN2/3.