Angiogenesis in male breast cancer

Quantitative evaluation of microvessel density using CD34 in clinical variants of ameloblastoma: An immunohistochemical study

Background:

Odontogenic epithelium plays an important role in the histogenesis of odontogenic tumors of the jaws. Ameloblastomas, which arise from odontogenic epithelium, are considered benign with little tendency to metastasize. Tumors require an adequate supply of oxygen and a way to remove their waste products. This can be achieved by angiogenesis. In situ quantification of the microvessel density (MVD) is a usual method for assessing angiogenesis. Moreover, angiogenesis may differ in subtypes of ameloblastomas and could play a role in determining the pattern of tumor growth.

Aim:

The aim of the present study was to demonstrate the expression of cluster of differentiation (CD34) in variants of ameloblastomas and to correlate and compare their expression to the aggressive behavior.

Materials and Methods:

A retrospective cross-sectional study which included forty paraffin blocks was conducted after obtaining ethical committee clearance. Ten cases of pyogenic granuloma were used as a positive control and thirty cases were of solid multicystic ameloblastoma (SMA), unicystic ameloblastoma (UA) and desmoplastic ameloblastomas. Angiogenesis was assessed using CD34 antigen and was immunohistochemically localized. Statistical analysis was carried out for comparative analysis with the help of ANOVA test, Kolmogorov–Smirnov test and least significance difference test.

Results:

A significant correlation was obtained between the MVD of all the three variants, i.e., SMA, UA and desmoplastic ameloblastomas which was statistically significant (P < 0.05).

Conclusion:

Increased MVD in the three variants, i.e., SMA, UA and desmoplastic ameloblastoma seen in the present study could suggest that the angiogenesis has an important role in tumor progression and aggressiveness of ameloblastomas.

Is routine pathological evaluation of tissue from gynecomastia necessary? A 15-year retrospective pathological and literature review

OBJECTIVE

To reconsider the routine plastic surgical practice of requesting histopathological evaluation of tissue from gynecomastia.

METHOD

The present study was a retrospective histopathological review (15-year period [1996 to 2012]) involving gynecomastia tissue samples received at the pathology laboratory in the Saskatoon Health Region (Saskatchewan). The Laboratory Information System (LIS) identified all specimens using the key search words "gynecomastia", "gynaecomastia", "gynecomazia" and "gynaecomazia". A literature review to identify all cases of incidentally discovered malignancies in gynecomastia tissue specimens over a 15-year period (1996 to present) was undertaken.

RESULTS

The 15-year LIS search detected a total of 452 patients that included two cases of pseudogynecomastia (0.4%). Patients' age ranged from five to 92 years and 43% of the cases were bilateral (28% left sided, 29% right sided). The weight of the specimens received ranged from 0.2 g to 1147.2 g. All cases showed no significant histopathological concerns. The number of tissue blocks sampled ranged from one to 42, averaging four blocks/case (approximately $105/case), resulting in a cost of approximately $3,200/year, with a 15-year expenditure of approximately $48,000. The literature review identified a total of 15 incidental findings: ductal carcinoma in situ (12 cases), atypical ductal hyperplasia (two cases) and infiltrating ductal carcinoma (one case).

CONCLUSIONS

In the context of evidence-based literature, and because no significant pathological findings were detected in this particular cohort of 452 cases with 2178 slides, the authors believe it is time to re-evaluate whether routine histopathological examination of tissue from gynecomastia remains necessary. The current climate of health care budget fiscal restraints warrants reassessment of the current policies and practices of sending tissue samples of gynecomastia incurring negative productivity costs on routine histopathological examination.

Male breast cancer: risk factors, biology, diagnosis, treatment, and survivorship

BACKGROUND

The causes, optimal treatments, and medical/psychosocial sequelae of breast cancer in men are poorly understood.

DESIGN

A systematic review of the English language literature was conducted to identify studies relevant to male breast cancer between 1987 and 2012 and including at least 20 patients. Searches were carried out on PubMed using the title terms 'male breast cancer' or 'male breast carcinoma'.

RESULTS

Relevant published data regarding risk factors, biological characteristics, presentation and prognosis, appropriate evaluation and treatment, and survivorship issues in male breast cancer patients are presented. BRCA2 mutations, age, conditions that alter the estrogen/androgen ratio, and radiation are proven risk factors. Disease biology is distinct in men, but diagnostic approaches and treatments for men are generally extrapolated from those in women due to inadequate research in men. Survivorship issues in men may include sexual and hormonal side-effects of endocrine therapies as well as unique psychosocial impacts of the disease.

CONCLUSION

Further research is needed to address gaps in knowledge pertaining to care of male breast cancer patients and survivors.

Expression of cell cycle proteins in male breast carcinoma

Introduction

Male breast cancer (MBC) is a rare, yet potentially aggressive disease. Although literature regarding female breast cancer (FBC) is extensive, little is known about the etiopathogenesis of male breast cancer. Studies from our laboratory show that MBCs have a distinct immunophenotypic profile, suggesting that the etiopathogenesis of MBC is different from FBCs. The aim of this study was to evaluate and correlate the immunohistochemical expression of cell cycle proteins in male breast carcinoma to significant clinico-biological endpoints.

Methods

75 cases of MBC were identified using the records of the Saskatchewan Cancer Agency over 26 years (1970-1996). Cases were reviewed and analyzed for the immunohistochemical expression of PCNA, Ki67, p27, p16, p57, p21, cyclin-D1 and c-myc and correlated to clinico-biological endpoints of tumor size, node status, stage of the disease, and disease free survival (DFS).

Results

Decreased DFS was observed in the majority of tumors that overexpressed PCNA (98%, p = 0.004). The overexpression of PCNA was inversely correlated to the expression of Ki67 which was predominantly negative (78.3%). Cyclin D1 was overexpressed in 83.7% of cases. Cyclin D1 positive tumors were smaller than 2 cm (55.6%, p = 0.005), had a low incidence of lymph node metastasis (38.2%, p = 0.04) and were associated with increased DFS of >150 months (p = 0.04). Overexpression of c-myc (90%) was linked with a higher incidence of node negativity (58.3%, p = 0.006) and increased DFS (p = 0.04). p27 over expression was associated with decreased lymph node metastasis (p = 0.04). P21 and p57 positive tumors were related to decreased DFS (p = 0.04). Though p16 was overexpressed in 76.6%, this did not reach statistical significance with DFS (p = 0.06) or nodal status (p = 0.07).

Conclusion

Aberrant cell cycle protein expression supports our view that these are important pathways involved in the etiopathogenesis of MBC. Tumors with overexpression of Cyclin D1 and c-myc had better outcomes, in contrast to tumors with overexpression of p21, p57, and PCNA with significantly worse outcomes. P27 appears to be a predictive marker for lymph nodal status. Such observation strongly suggests that dysregulation of cell cycle proteins may play a unique role in the initiation and progression of disease in male breast cancer. Such findings open up new avenues for the treatment of MBC as a suitable candidate for novel CDK-based anticancer therapies in the future.

Survival of male breast cancer patients: population-based cohort study

Little information is available on the survival of male breast cancer patients because the disease is extremely rare in men. Moreover, previous reports on the prognosis of male breast cancer have been conflicting. We took advantage of a number of large, nationwide registries in Sweden to evaluate the prognostic value of sex in breast cancer patients. A population-based cohort of 269 male and 30 011 female breast cancer patients born after 1935 and diagnosed with primary breast cancer between 1970 and 1997 was generated by linking a number of Swedish registries, including the Swedish Cancer Registry, the Cause of Death Registry, the Swedish Generation Registry, and the Registry of Population and Population Changes. We used this cohort to quantify the association between the sex of the patient and breast cancer-specific mortality, using the Cox proportional hazards. The sex of the patient did not significantly influence the prognosis of breast cancer. Adjusting for age at diagnosis and calendar period did not alter the results. Nor did the results change when the analyses were repeated for all causes of morality. Our study, one of the largest to date, failed to find evidence to support the proposed association between the sex of breast cancer patients and survival. Given the previous reports, which advocated that male breast cancer patients have poorer survival and need aggressive treatment strategies, our findings are reassuring and clinically very important.

Interleukin-8 modulates growth and invasiveness of estrogen receptor-negative breast cancer cells

Breast cancer, especially estrogen receptor (ER)-negative breast cancer, remains hard to treat despite major advances in surgery and adjuvant therapies. The deletion of ER has been consistently associated with tumor progression, recurrence, metastasis and poor prognosis. Among other differences in biological features, ER-negative breast cancers express high levels of interleukin-8 (IL-8), whereas their ER-positive counterparts do not. IL-8 is a multi-functional cytokine with many important biological functions in tumor formation and development. We aimed to study the role(s) of IL-8 in ER-negative breast cancer progression by using RNA interference to specifically knockdown IL-8 expression in ER-negative breast cancer cell lines MDA-MB-231 and MDA-MB-468. In vitro, suppression of IL-8 led to significant reductions in cell invasion (p<0.001), but had no effects on cell proliferation or cell cycle. In vivo, suppression of IL-8 significantly reduced the microvessel density (p<0.05), and markedly reduced neutrophil infiltration into the tumors (p<0.05). In contrast to in vitro observations, suppression of IL-8 promoted tumor growth in nude mice (p<0.05). Our results imply that the complex roles of IL-8 in the regulation of ER-negative breast cancer progression may in part be related to its potent chemotactic effects on neutrophils, which in turn mediates many of the biological functions of IL-8.

Overexpression of carcinoma and embryonic cytotrophoblast cell-specific Mig-7 induces invasion and vessel-like structure formation

Molecular requirements for carcinoma cell interactions with the microenvironment are critical for disease progression but are poorly understood. Integrin alpha v beta 5, which senses the extracellular matrix, is important for carcinoma cell dissemination in vivo. alpha v beta 5 signaling induces Mig-7, a novel human gene product that is apparently carcinoma-specific. We hypothesized that Mig-7 expression facilitates tumor cell dissemination by increasing invasion and vasculogenic mimicry. Results show that embryonic cytotrophoblasts up-regulated Mig-7 expression before they acquired an invasive phenotype capable of pseudovasculogenesis. Mig-7 protein primarily co-localized with vasculogenic mimicry markers factor VIII-associated antigen, vascular endothelial-cadherin, and laminin 5 gamma 2 chain domain III fragment in lymph node metastases. Overexpression of Mig-7 increased gamma 2 chain domain III fragments known to contain epidermal growth factor (EGF)-like repeats that can activate EGF receptor. Interestingly, EGF also induced Mig-7 expression. Carcinoma cell adhesion to laminins was significantly reduced by Mig-7 expression. Remarkably, in two-dimensional and three-dimensional Matrigel cultures, Mig-7 expression caused invasion and vessel-like structures. Melanoma cells, which were previously characterized to invade aggressively and to undergo vasculogenic mimicry, expressed Mig-7. Taken together, these data suggest that Mig-7 expression allows cells to sense their environment, to invade, and to form vessel-like structures through a novel relationship with laminin 5 gamma 2 chain domain III fragments.

Beta2-microglobulin promotes the growth of human renal cell carcinoma through the activation of the protein kinase A, cyclic AMP-responsive element-binding protein, and vascular endothelial growth factor axis

PURPOSE

Beta(2)-microglobulin (beta2M), a soluble protein secreted by cancer and host inflammatory cells, has various biological functions, including antigen presentation. Because aberrant expression of beta2M has been reported in human renal cell carcinoma, we investigated the effects of beta2M overexpression on cancer cell growth and analyzed its molecular signaling pathway.

EXPERIMENTAL DESIGN

We established clonal cell lines that overexpressed beta2M in human renal cell carcinoma (SN12C) cells and then examined cell growth in vitro and in vivo and studied the beta2M-mediated downstream cell signaling pathway.

RESULTS

Our results showed that beta2M expression positively correlates with (a) in vitro growth on plastic dishes and as Matrigel colonies, (b) cell invasion and migration in Boyden chambers, and (c) vascular endothelial growth factor (VEGF) expression and secretion by cells. We found, in addition, that beta2M mediates its action through increased phosphorylation of cyclic AMP-responsive element-binding protein (CREB) via the protein kinase A-CREB axis, resulting in increased VEGF expression and secretion. In convergence with this signal axis, beta2M overexpression also activated both phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase pathways. Beta2M overexpression induced accelerated growth of SN12C in mouse subcutis and bone. Interrupting the beta2M signaling pathway using small interfering RNA led to apoptosis with increased activation of caspase-3 and caspase-9 and cleaved poly(ADP-ribose) polymerase.

CONCLUSIONS

Our results showed for the first time that the beta2M-protein kinase A-CREB-VEGF signaling axis plays a crucial role in support of renal cell carcinoma growth and progression and reveals a novel therapeutic target.

Male breast cancer: a gender issue

The incidence of male breast cancer (MBC) is rising; however, mortality due to MBC has not changed, unlike female breast cancer. This lack of change is mostly attributable to a lack of major progress in the understanding and treatment of the disease. The treatment of MBC has been extrapolated from the knowledge of female breast cancer, despite the multiple differences in the pathogenesis, biology and genetics of these two disease entities, especially the differences with regard to the role of male hormones as well as estrogens in MBC compared with female disease. Although major advances in hormonal manipulation for the treatment of breast cancer are being developed, an improved understanding of the potential differences between male and female breast cancer is essential, as this would provide new opportunities for therapeutic intervention and probable improved outcome for MBC. This review aims at highlighting the major differences between male and female breast cancer with an emphasis on hormonal therapy, and discusses some of the recent advances in MBC.