Differences in phenotype and gene expression of prostate stromal cells from patients of varying ages and their influence on tumour formation by prostate epithelial cells

Prostate cancer （PCa） is an age-related disease, and the stromal microenvironment plays an important role in prostatic malignant progression. However, the differences in prostate stromal cells present in young and old tissue are still obscure. We established primary cultured stromal cells from normal prostatic peripheral zone （PZ） of donors of varying ages and found that cultured stromal cells from old donors （PZ-old） were more enlarged and polygonal than those from young donors （PZ-young）. Furthermore, based on immunocytochemical and ultrastructural analysis, the components of stromal cells changed from a majority of fibroblasts to a mixture of fibroblasts and myofibroblasts with increasing donor age. Using a three-dimensional in vitro culture system, we found that PZ-old stromal cells could enhance the proliferation, migration and invasion of cocultured benign BPH-1 and PC-3 cells. Using an in vivo tissue recombination system, we also found that PZ-old stromal cells are more effective than PZ-young cells in promoting tumour formation by BPH-1 cells of high passage（〉100） and PC-3 cells. To probe the possible mechanism of these effects, we performed cDNA microarray analysis and profiled 509 upregulated genes and 188 downregulated genes in PZ-old cells. Among the changed genes, we found genes coding for a subset of paracrine factors that are capable of influencing adjacent epithelial cells; these include hepatocyte growth factor （HGF）, fibroblast growth factor 5 （FGF5）, insulin-like growth factor 2 （IGF2）, insulin-like growth factor-binding protein 4 （IGFBP4）, IGFBP5 and matrix metallopeptidase 1 （MMP1）. Changes in the expression of these genes were further confirmed by quantitative real-time polymerase chain reaction （PCR）, Western blotting and enzyme-linked immunosorbent assays. Overall, our findings indicate that stromal cells from prostate PZ of old donors are more active than similar cells from young donors in promoting the malignant process of adjacent epithelial cells. This finding hints at a new potential strategy for the prevention of PCa.

Comparison of Cancer Incidence between China and the USA

Objective The incidence of cancer varies around the globe,especially between less-developed and developed regions.The aim of this study is to explore differences in cancer incidence between China and the USA. Methods Data were obtained from the GLOBOCAN 2008 database.Estimated numbers of new cancer cases in the USA were obtained from the American Cancer Society,while the numbers of cases in China,including those in urban and rural areas,were obtained from 36 cancer registries(2003-2005).Cancer incidence for major sites between China and the USA were analyzed. Results In China,lung cancer was the predominant type of cancer detected in males;in females,breast cancer was the main type of cancer.Gastrointestinal cancers,such as those of the liver,stomach,and esophagus,were more commonly seen in China than in the USA.A significant difference in the incidence of melanoma of the skin was observed between China and the USA.During comparison of differences in the age-standardized rates by world population(ASRWs) of major cancer sites between the two countries,4 sites in males(i.e.,nasopharynx,esophagus,stomach,and liver) and 6 sites in females(i.e.,nasopharynx,esophagus,stomach,liver, gallbladder,and cervix uteri) showed higher cancer incidence rates in China than in the USA. Conclusions Significant differences in cancer incidence sites were found between the two countries.Cancer may be prevented through public education and awareness.Programs to promote cancer prevention in China,especially those of the lung,breast,and gastrointestinal region,must also be implemented.

What is New in Supportive Care in Cancer？

The Annual Symposium of the Multinational Association of Supportive Care in Cancer （MASCC）/International Society of Oral Oncology （ISOO） was held in Vancouver, Canada,June 24-26, 2010. The symposium brought together health care professionals from many countries and many fields of expertise for an excellent forum of ideas, lectures and collegial interactions,and discussed methods to minimize cancer-induced side effects, the symptoms and complications of its treatment, and psychosocial issues facing cancer patients and their families. Some ideas and studies selected from the presentations of different fields of supportive care in cancer presented in this symposium are introduced in this paper.