Hypoxia modulates the stem cell population and induces EMT in the MCF-10A breast epithelial cell line.

A common feature among pre-malignant lesions is the induction of hypoxia through increased cell propagation and reduced access to blood flow. Hypoxia in breast cancer has been associated with poor patient prognosis, resistance to chemotherapy and increased metastasis. Although hypoxia has been correlated with factors associated with the latter stages of cancer progression, it is not well documented how hypoxia influences cells in the earliest stages of transformation. Using the immortalized MCF-10A breast epithelial cell line, we used hypoxic culture conditions to mimic reduced O2 levels found within early pre-malignant lesions and assessed various cellular parameters. In this non-transformed mammary cell line, O2 deprivation led to some changes not immediately associated with cancer progression, such as decreased proliferation, cell cycle arrest and increased apoptosis. In contrast, hypoxia did induce other changes more consistent with an increased metastatic potential. A rise in the CD44+CD24-/low-labeled cell sub-population along with increased colony forming capability indicated an expanded stem cell population. Hypoxia also induced cellular and molecular changes consistent with an epithelial-to-mesenchymal transition (EMT). Furthermore, these cells now exhibited increased migratory and invasive abilities. These results underscore the contribution of the hypoxic tumour microenvironment in cancer progression and dissemination.

Pediatric cancer genetics.

PURPOSE OF REVIEW: The current review will focus on the current knowledge of the contribution of both germline and somatic mutations to the development and management of cancer in pediatric patients. RECENT FINDINGS: It has long been thought that genetic mutations in both germline and somatic cells can contribute to the development of cancer in pediatric patients. With the recent advances in genomic technologies, there are now over 500 known cancer predisposition genes. Recent studies have confirmed an 8.5-14% germline mutation rate in cancer predisposition genes in pediatric cancer patients. SUMMARY: The discovery of both germline and somatic cells mutation(s) in pediatric cancer patients not only aids in the management of current disease, but can also have direct implications for future management as well as the medical management of family members.

Acquired microcephaly in blepharophimosis-ptosis-epicanthus inversus syndrome because of an interstitial 3q22.3q23 deletion.

BACKGROUND: Blepharophimosis-ptosis-epicanthus inversus syndrome is an autosomal dominant condition because of mutations or deletions of the FOXL2 gene. Microcephaly is not associated with FOXL2 mutations but has been reported in individuals with chromosome 3q deletions, which include the FOXL2 gene and other contiguous genes. The ATR gene has been reported as a candidate gene for microcephaly in individuals with contiguous deletion of chromosome 3q involving the FOXL2 gene. PATIENT: We describe a girl with blepharophimosis-ptosis-epicanthus inversus syndrome along with acquired microcephaly and intellectual disability. RESULTS: Our patient had a deletion of chromosome 3q22.2q23, which does not include the ATR gene but does include the PIK3CB gene as a candidate gene for microcephaly. CONCLUSION: We propose that the PIK3CB gene included in our patient's chromosome 3q deletion may be the gene responsible for microcephaly and other patients with blepharophimosis-ptosis-epicanthus inversus syndrome because of a chromosome 3q deletion.

Loss of PTEN expression is associated with IGFBP2 expression, younger age, and late stage in triple-negative breast cancer.

OBJECTIVES: To investigate the association between PTEN loss and IGFBP2 expression in a series of triple-negative breast cancers and to relate this expression to basal cytokeratin expression and clinicopathologic features. METHODS: One hundred and one formalin-fixed and paraffin-processed triple-negative breast cancer cases from the University of Malaya Medical Centre were tested immunohistochemically for cytokeratins 5/6 and 14, PTEN, and IGFBP2. The resulting slides were scored for proportion and intensity of staining. RESULTS: Loss of tumor nuclear and cytoplasmic staining for PTEN occurred in 48.3% of cases and was significantly associated with younger age at diagnosis (47 years compared with 57 years in those without PTEN loss; P = .005). Independent predictors of PTEN loss were late stage at presentation (P = .026), cytokeratin 5/6 positivity (P = .028), and IGFBP2 expression (P = .042). High levels of IGFBP2 expression were seen in 32% of cases; an independent predictor of high levels was cytokeratin 14 negativity (P = .005). PTEN loss and high levels of IGFBP2 expression were associated with poorer survival, but neither of these trends was significant. CONCLUSIONS: PTEN loss is a frequent event in triple-negative breast cancers and is significantly associated with younger age at onset of breast cancer, late stage, and IGFBP2 expression.

The reliability of rabbit monoclonal antibodies in the immunohistochemical assessment of estrogen receptors, progesterone receptors, and HER2 in human breast carcinomas.

The reliability of the rabbit monoclonal antibodies SP1, SP2, SP3, and 4B5 was immunohistochemically assessed on a range of 96 invasive breast carcinomas and the results compared with those achieved with established antibody markers for estrogen receptors (6F11), progesterone receptors (PgR636), and HER2 (polyclonal A0485 and clone CB11), with HER2 status validated by fluorescence in situ hybridization (FISH) and silver in situ hybridization. Optimal results depended on the duration of microwave antigen-retrieval time and the use of a high pH buffer for rabbit and mouse estrogen receptor antibodies (SP1 and 6F11), although only on antigen-retrieval duration for the progesterone receptors SP2 and PgR636. The highest rate of concordance between HER2 overexpression and HER2 gene amplification was with the rabbit monoclonal antibodies (SP3 and 4B5) and FISH. Rabbit monoclonal antibodies are reliable alternatives to established antibody markers for the immunohistochemical testing of estrogen receptors, progesterone receptors, and HER2 in breast cancer.

Preparedness for hospital practice among graduates of a problem-based, graduate-entry medical program.

OBJECTIVE: To compare preparedness for hospital practice between graduates from a problem-based, graduate-entry medical program and those from other programs (undergraduate problem-based and traditional). DESIGN: Survey of graduates (by mailed questionnaire) and organisers of clinical training (by semistructured interview); results were compared with published results of surveys of graduates from other programs. SETTING AND PARTICIPANTS: All graduates of the first intake of the University of Sydney graduate-entry medical program were surveyed at the end of their first intern year (2001), along with the director of clinical training or intern manager at each of the New South Wales hospitals that employed the graduates. MAIN OUTCOME MEASURES: Graduates' self-reported level of preparedness in the eight domains of the Preparation for Hospital Practice Questionnaire; and organisers' opinions of their strengths and weaknesses. RESULTS: 76 of 108 graduates from the graduate-entry program (70%) and organisers of clinical training at all 17 hospitals participated. Graduates from the program felt more prepared than did those from other programs in five of the eight domains assessed (interpersonal skills, confidence, collaboration, holistic care, and self-directed learning) and no less prepared in any domain. Organisers rated the graduates highly, especially in clinical competence, confidence, communication and professional skills. Opinions of interns' knowledge of basic sciences conflicted, with strengths and weaknesses mentioned with equal frequency. CONCLUSION: Graduates from the graduate-entry, problem-based program are at least as well prepared for their intern year as graduates from traditional and undergraduate problem-based programs.