Search

Breast cancer is the most common cancer in women worldwide. The growth of breast cancer cells is either hormone-dependent or hormone-independent. Both types are represented in vitro by the estrogen-receptor positive (ER+) MCF-7 and the estrogen-receptor negative (ER−) MDA-MB-231 cell lines, respectively. The pS2 gene is an estrogen-regulated gene and serves as a marker for the ER+ tumours. Carotenoids are pigments with anti-cancer properties besides having pro-vitamin A, antioxidant and free-radical quenching effects. This study was designed firstly, to compare the effect of palm oil carotene concentrate with retinoic acid on the growth of the ER+ MCF-7 and the ER− MDA-MB-231 cells; and secondly to evaluate the effect of the palm oil carotene concentrate on the regulation of pS2 mRNA. The growth experiments were performed with monolayer cells seeded in phenol red free RPMI 1640 culture media and subsequently treated with varying concentrations of either retinoic acid or palm oil carotenoids. The cell numbers were determined at the start of each experiment and then at successive time intervals. The results showed that the palm oil carotene concentrate caused dose-dependent inhibition of estradiol-stimulated growth of MCF-7 cells but did not affect the proliferation of MDA-MB-231 cells. Retinoic acid caused similar, albeit more potent effects, as significant inhibition was observed at lower concentrations than the palm oil carotenoids. In the pS2 gene expression experiment, cell monolayers were treated with the carotene concentrate (10 −6 M), either with or without supplemented estradiol (10 −8 M), and subsequently the RNA was extracted. Northern blotting was performed and the regulation of pS2 mRNA determined using a 32 P-labelled pS2 cDNA probe. The results showed that the palm oil carotene concentrate did not affect the expression of pS2 mRNA and are therefore independent of the estrogen-regulated pathway.

Oestrogen is important in the development of breast cancer. Oestrogen receptor positive breast cancers are associated with a better prognosis than oestrogen-receptor negative breast cancers since they are more responsive to hormonal treatment. Oestrone sulphate acts as a huge reservoir for oestrogens in the breast. It is converted to the potent oestrogen, oestradiol (E(2)) by the enzymes oestrone sulphatase and oestradiol-17beta hydroxysteroid dehydrogenase (E(2)DH). Retinoic acid and carotenoids have been shown to have chemopreventive activity against some cancers. The aim of our study was to determine and compare the effects of retinoic acid and palm oil carotenoids on growth of and oestrone sulphatase and E(2)DH activities in the oestrogen receptor positive, MCF-7 and oestrogen receptor negative, MDA-MB-231 breast cancer cell lines. Retinoic acid and carotenoids inhibited MCF-7 cell growth but had no effect on MDA-MB-231 cell growth. Both retinoic acid and carotenoids stimulated oestrone sulphatase activity in the MCF-7 cell line. E(1) to E(2) conversion was inhibited by 10(-7) M carotenoids but was stimulated at 10(-6) M in the MCF-7 cell line. Retinoic acid had no effect on E(1) to E(2) conversion at 10(-7) M but stimulated E(1) to E(2) conversion at 10(-6) M. Retinoic acid and carotenoids had no effect on E(2) to E(1) conversion in the MCF-7 cell line. Retinoic acid stimulated E(1) to E(2) conversion in the MDA-MB-231 cell line but had no effect on oestrone sulphatase activity or E(2) to E(1) conversion in this cell line. Both oestrone sulphatase and E(2)DH activity were not affected by carotenoids in the MDA-MB-231 cell line. In conclusion, retinoic acid and carotenoids may prevent the development of hormone-dependent breast cancers since they inhibit the growth of the MCF-7 cell line.

Background: Interpretative commenting is an important activity of the clinical diagnostic laboratory. We describe a study of interpretative commenting abilities among senior laboratory professionals in the Asia-Pacific region and Africa. Methods: Five sets of laboratory results reflecting common and important problems encountered in clinical chemistry were distributed at 4-weekly intervals to 31 registered participants from countries in the Asia-Pacific region and Africa. Participants were asked to attach an interpretative comment to the results assuming that the requesting doctor had asked for an interpretation of the result. Results: Twelve pathologists and 19 scientists from seven countries registered to participate and the overall reply rate was ∼50% for the five cases. The quality of the comments returned by participants was diverse and some reflected incorrect or misleading interpretation and advice. Conclusions: While interpretative commenting is an important laboratory activity, the results of this study suggest that there is room for improvement in the quality of interpretative comments offered by senior laboratory professionals, even for commonly reported results relating to most prevalent and important public health conditions. Interpretative commenting should be formally taught during training of pathologists and scientists, and continuing professional development in this area is required for the provision of a quality interpretative service. Clin Chem Lab Med 2009;47:963–70.

HbA1c is used for assessing glycaemic control in patients with diabetes. It is also used for treatment goals and as a target for therapeutic intervention. The Direct Control and Complications Trial in the USA showed that HbA1c can be used to predict the risk of complications. Hence, it is important for HbA1c assays to be standardised. The National Glycohemoglobin Standardization Program (NGSP) in the USA was formed in 1996 so that HbA1c results from different laboratories would be comparable to those reported in the DCCT study. There were also HbA1c standardisation programmes in Sweden and Japan. These three standardisation programmes are, in fact, direct comparison methods (DCMs), and yield different HbA1c results. In 1994, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) established a Working Group on Standardisation of HbA1c. This working group has developed a global HbA1c reference system with very much improved intra-assay and inter-assay coefficients of variation. Recommendations have been made to report HbA1c results as IFCC-HbA1c values in SI units (mmol HbA1c/mol Hb) and NGSP-HbA1c (%) as well as estimated average glucose (eAG), once a tight relationship has been shown to exist between eAG and HbA1c.

Gross cystic breast disease is a common condition in women. Women with apocrine breast cysts (breast cyst fluid Na+/K+ less than 3) may be at higher risk of breast cancer than women who have cysts lined by flattened epithelium (Na+/K+ greater than or equal to 3). Breast cyst fluid concentrations of epidermal growth factor were significantly higher in the low electrolyte ratio group than in the high electrolyte ratio group (356.2 ng/ml vs 104.1 ng/ml, P less than 0.0003). A negative correlation was obtained between intracystic epidermal growth factor concentrations and Na+/K+ (rs = -0.666, P less than 0.001). No significant difference was found between the total oestradiol concentrations in the two cyst groups. However, the unbound oestradiol concentrations on a limited number of samples were significantly higher in the low electrolyte ratio group than in the high electrolyte ratio group (P less than 0.05). The higher concentrations of EGF in cyst fluid with Na+K+ less than 3 may explain why women with apocrine breast cysts may be at increased risk of developing breast cancer.

Transforming growth factor-beta (TGFbeta) is present, predominantly in latent forms, in normal and malignant breast tissue. The mechanisms by which latent TGFbeta is activated physiologically remain largely an enigma. The objective of this study was to assess whether the proteases, cathepsin D and prostate specific antigen (PSA) could activate latent TGFbeta1 and TGFbeta2 in conditioned media of the hormone-dependent MCF-7 and hormone-independent MDA-MB-231 human breast cancer cell lines, newly purchased from ATCC. Both of the cell lines were seeded in 6-well plates 2 days prior to treatment with varying concentrations of cathepsin D and PSA. Active TGFbeta1 and TGFbeta2 in the media were then measured by ELISA after 4, 8, 24 and 72 hours of treatment. TGFbeta1 and TGFbeta2 mRNA expression of both cell lines were measured by RT-PCR to determine whether any increase in level of active TGFbeta1 and TGFbeta2 was due to increased production. There was a significant increase in only active TGFbeta2 levels in the MDA-MB-231 cell line with both treatments. Cathepsin D and PSA did not have any effect on TGFbeta1 and TGFbeta2 mRNA expression. Cathepsin D and PSA were unable to activate latent TGFbeta1 and TGFbeta2 in these two breast cancer cell lines. A constant level of TGFbeta2 mRNA in the control and treated MDA-MB-231 cells suggests that the increase in level of active TGFbeta2 was not a result of increased production but was likely to be due to activation by a mechanism independent of cathepsin D and PSA.

Goniothalamin (GTN) is a styrylpyrrone derivative from Goniothalamus umbrosus and other Annonaceae species. It has been shown to have anti-cancer and apoptosis-inducing properties against various human tumour and animal cell lines. The compound has also been shown to be active in vivo against DMBA-induced rat mammary tumours and was reported as an anti-fertility agent in rats. The aim of our study was to assess the genotoxicity of GTN in CHO cells using the UKEMS guidelines. A metabolic activation fraction (S9) was prepared according to standard methods. The methylthiazoletetrazolium (MTT) screening assay was then carried out to determine the cytotoxicity index (IC 50 ) of GTN. The average IC 50 value was 12.45 (± 3.63) μM. The mitotic index (MI) assay was then performed to determine the clastogenicity indices (MI C25 , MI C50 and MI C100 ) of GTN. The chromosome aberration (CA) induction assay using air-dried metaphase spread was then performed to investigate the clastogenic effects of goniothalamin. Benzo[a]pyrene (BaP) and ethylmethanesulphonate (EMS) were used as positive controls in the presence and absence of S9 metabolic activation, respectively. The anti-genotoxicity effect of GTN was also assessed using a combination of GTN and EMS, and GTN and BaP. Dose–responses of CA frequencies were determined for both, the genotoxicity and anti-genotoxicity effects. GTN on its own and when combined with positive controls, was found to induce and enhance CA, respectively. Chromatid and whole chromosome breaks/gaps, as well as interchanges, endoreduplications and ring chromosomes were the main types of aberration induced by GTN. The overall clastogenic effect of GTN was statistically significant. In conclusion, GTN is potentially a genotoxic or clastogenic substance without any anti-genotoxic properties.

The prevalence of diabetes is increasing worldwide. The World Health Organisation has estimated that there will be around 300 million diabetics by 2025. The largest increase will occur in Asia. The prevalence of type 2 diabetes is increasing due to a combination of factors: increasing lifespan, sedentary lifestyle, excessive intake of high energy foods, increasing prevalence of overweight/obese people. The Finnish Diabetes Prevention Study Group has clearly shown that changes in the lifestyle of both overweight men and women with impaired glucose tolerance can reduce the incidence of type 2 diabetes by 58%. This finding was confirmed by the Diabetes Prevention Programme which found that lifestyle intervention in individuals with impaired fasting glucose or impaired glucose tolerance reduced the risk of developing type 2 diabetes by 58%, whereas treatment with metformin reduced the risk of type 2 diabetes by only 31%. Both acarbose and troglitazone have also been shown to reduce the progression to diabetes in individuals who are at high risk of developing type 2 diabetes. Since the cure for diabetes remains some way off our concerted efforts should be directed at prevention of diabetes in order to curb the increasing prevalence of diabetes worldwide. Lifestyle changes are more beneficial than long term drug therapy in the prevention of diabetes and should be actively promoted.

Breast cancer is the most common cancer in women worldwide and its incidence is increasing. Oestrogens and mitogenic growth factors may play an important role in the development of breast cancer, whereas inhibitory growth factors may prevent the development of breast cancer. Only about 5 to 10% of cases of breast cancer are due to inheritance of mutations in the BRCA1 or BRCA2 tumour suppressor genes. Mutations in the p53 tumour suppressor gene are commonly found in sporadic breast cancers. Retinoic acid and carotenoids may play a protective role in breast cancer since they inhibit the growth of the oestrogen receptor-positive MCF-7 breast cancer cell line. The presence of oestrogen and progesterone receptors predicts the likelihood of benefit from hormonal therapy. Amplification of the c-erbB2 oncogene in breast cancers is associated with a poor prognosis. It is now apparent that there is a complex, productive cross-talk between oestrogen-directed and growth factor-directed pathways which are believed to markedly reinforce their individual cellular effects on growth and gene responses.