Pro-matrix metalloproteinase-2 transfection increases orthotopic primary growth and experimental metastasis of MDA-MB-231 human breast cancer cells in nude mice

The ability to activate pro-matrix metalloproteinase (pro-MMP)-2 via membrane type-MMP is a hallmark of human breast cancer cell lines that show increased invasiveness, suggesting that MMP-2 contributes to human breast cancer progression. To investigate this, we have stably transfected pro-MMP-2 into the human breast cancer cell line MDA-MB-231, which lacks MMP-2 expression but does express its cell surface activator, membrane type 1-MMP. Multiple clones were derived and shown to produce pro-MMP-2 and to activate it in response to concanavalin A. In vitro analysis showed that the pro-MMP-2-transfected clones exhibited an increased invasive potential in Boyden chamber and Matrigel outgrowth assays, compared with the parental cells or those transfected with vector only. When inoculated into the mammary fat pad of nude mice, each of the MMP-2-tranfected clones grew faster than each of the vector controls tested. After intracardiac inoculation into nude mice, pro-MMP-2-transfected clones showed a significant increase in the incidence of metastasis to brain, liver, bone, and kidney compared with the vector control clones but not lung. Increased tumor burden was seen in the primary site and in lung metastases, and a trend toward increased burden was seen in bone, however, no change was seen in brain, liver, or kidney. This data supports a role for MMP-2 in breast cancer progression, both in the growth of primary tumors and in their spread to distant organs. MMP-2 may be a useful target for breast cancer therapy when refinement of MMP inhibitors provides for MMP-specific agents.

Transfection of MDA-MB-231 human breast carcinoma cells with bone sialoprotein (BSP) stimulates migration and invasion in vitro and growth of primary and secondary tumors in nude mice

We have investigated the role of bone sialoprotein (BSP), a secreted glycoprotein normally found in bone, in breast cancer progression. To explore functions for BSP in human breast cancer invasion and metastasis, the full-length BSP cDNA was transfected into the MDA-MB-231-BAG human breast cancer cell line under the control of the CMV promoter. Clones expressing BSP and vector control clones were isolated. BSP producing clones showed increased monolayer wound healing, a faster rate of stellate outgrowth in Matrigel and increased rate of invasion into a collagen matrix when compared to control clones. Clones were also examined in models of breast cancer growth and metastasis in vivo. BSP transfected clones showed an increased rate of primary tumor growth following mammary fat pad injection of nude mice. BSP transfected clones and vector control clones metastasized to soft organs and bone at a similar rate after intra-cardiac injection as determined by real-time PCR and X-ray analysis. Although these organs were targets for both BSP transfected and non-transfected cells, the size of the metastatic lesion was shown to be significantly larger for BSP expressing clones. This was determined by real-time PCR analysis for soft organs and by X-ray analysis of bone lesions. For bone this was confirmed by intra-tibial injections of cells in nude mice. We conclude that BSP acts to drive primary and secondary tumor growth of breast cancers in vivo.

Human breast cancer cell metastasis to long bone and soft organs of nude mice : a quantitative assay

Bone is a common metastatic site in human breast cancer (HBC). Since bone metastasis occurs very rarely from current spontaneous or experimental metastasis models of HBC cells in nude mice, an arterial seeding model involving the direct injection of the cells into the left ventricle has been developed to better understand the mechanisms involved in this process. We present here a sensitive polymerase chain reaction (PCR) method to detect and quantitate bone and soft organ metastasis in nude mice which have been intracardially inoculated with Lac Z transduced HBC cells. Amplification of genomically incorporated Lac Z sequences in MDA-MB-231-BAG HBC cells enables us to specifically detect these cells in mouse organs and bones. We have also created a competitive template to use as an internal standard in the PCR reactions, allowing us to better quantitate levels of HBC metastasis. The results of this PCR detection method correlate well with cell culture detection from alternate long bones from the same mice, and are more sensitive than gross Lac Z staining with X-gal or routine histology. Comparable qualitative results were obtained with PCR and culture in a titration experiment in which mice were inoculated with increasing numbers of cells, but PCR is more quantifiable, less time consuming, and less expensive. This assay can be employed to study the molecular and cellular aspects of bone metastasis, and could easily be used in conjunction with RT-PCR-based analyses of gene products which may be involved with HBC metastasis.

Correlation between extent of osteolytic damage and metastatic burden of human breast cancer metastasis in nude mice : real-time PCR quantitation

Orthotopic or intracardiac injection of human breast cancer cell lines into immunocompromised mice allows study of the molecular basis of breast cancer metastasis. We have established a quantitative real-time PCR approach to analyze metastatic spread of human breast cancer cells inoculated into nude mice via these routes. We employed MDA-MB-231 human breast cancer cells genetically tagged with a bacterial β-galactosidase (Lac-Z) retroviral vector, enabling their detection by TaqMan® real-time PCR. PCR detection was linear, specific, more sensitive than conventional PCR, and could be used to directly quantitate metastatic burden in bone and soft organs. Attesting to the sensitivity and specificity of the PCR detection strategy, as few as several hundred metastatic MDA-MB-231 cells were detectable in 100 μm segments of paraffin-embedded lung tissue, and only in samples adjacent to sections that scored positive by histological detection. Moreover, the measured real-time PCR metastatic burden in the bone environment (mouse hind-limbs, n = 48) displayed a high correlation to the degree of osteolytic damage observed by high resolution X-ray analysis (r2 = 0.972). Such a direct linear relationship to tumor burden and bone damage substantiates the so-called 'vicious cycle' hypothesis in which metastatic tumor cells promote the release of factors from the bone which continue to stimulate the tumor cells. The technique provides a useful tool for molecular and cellular analysis of human breast cancer metastasis to bone and soft organs, can easily be extended to other cell/marker/organ systems, and should also find application in preclinical assessment of anti-metastatic modalities.

Three-dimensional cultures of normal human osteoblasts: proliferation and differentiation potential in vitro and upon ectopic implantation in nude mice.

This paper is novel andreports on the in vitro establishment of 3-D cultures of human osteoblasts. These were evaluated for protein markers of bone cells. Sequentially alkaline phosphatase, calcium incorporation for matrix mineralisation and then finally osteocalcin expression were detected in cultures. The extracellular matrix was composed of type 1 collagen and as it mineralised, needle shaped crystals were often associated with matrix vesicles initiating mineralisation. In vivo implantation in nude mice showed progression of mineralisation from the inner region outward with peripheral cells in a non-mineralised matrix. Host vessels invaded the implanted cell area. The research has relevance to musculoskeletal tissue engineering.

TRIP-Br2 promotes oncogenesis in nude mice and is frequently overexpressed in multiple human tumors

Background: Members of the TRIP-Br/SERTAD family of mammalian transcriptional coregulators have recently been implicated in E2F-mediated cell cycle progression and tumorigenesis. We, herein, focus on the detailed functional characterization of the least understood member of the TRIP-Br/SERTAD protein family, TRIP-Br2 (SERTAD2).

Nude and naked : refiguring voyeuristic structures through feminist photographic techniques

Using theoretical, aesthetic and formal means specific to photographic processes, the relational exegesis and exhibition "Visual pleasures" attempts to disrupt visual structures and notions that have traditionally been used to objectify and idealize the body and, at the same time, open the field of vision to alternative and lived feminine pleasures.

The female nude

This thesis argues that a sense of personal power, agency and self-worth can be regained through art practice and will cite examples of this process by artists and others who are outside the parameters of hegemony. The author's experience as a female artist is discussed within the context of historical and contemporary art practices that focus mainly on representations of the female nude, and therefore follows the notion that the personal is political.

Nude dalliance with alien abductions turns into a close encounter of the dull kind

Review : Balletlab's  ' And All Things Return to Nature Tomorrow'

Transfection of MDA-MB-231 human breast carcinoma cells with bone sialoprotein (BSP) stimulates migration and invasion in vitro and growth of primary and secondary tumors in nude mice

We have investigated the role of bone sialoprotein (BSP), a secreted glycoprotein normally found in bone, in breast cancer progression. To explore functions for BSP in human breast cancer invasion and metastasis, the full-length BSP cDNA was transfected into the MDA-MB-231-BAG human breast cancer cell line under the control of the CMV promoter. Clones expressing BSP and vector control clones were isolated. BSP producing clones showed increased monolayer wound healing, a faster rate of stellate outgrowth in Matrigel and increased rate of invasion into a collagen matrix when compared to control clones. Clones were also examined in models of breast cancer growth and metastasis in vivo. BSP transfected clones showed an increased rate of primary tumor growth following mammary fat pad injection of nude mice. BSP transfected clones and vector control clones metastasized to soft organs and bone at a similar rate after intra-cardiac injection as determined by real-time PCR and X-ray analysis. Although these organs were targets for both BSP transfected and non-transfected cells, the size of the metastatic lesion was shown to be significantly larger for BSP expressing clones. This was determined by real-time PCR analysis for soft organs and by X-ray analysis of bone lesions. For bone this was confirmed by intra-tibial injections of cells in nude mice. We conclude that BSP acts to drive primary and secondary tumor growth of breast cancers in vivo.

Correlation between extent of osteolytic damage and metastatic burden of human breast cancer metastasis in nude mice: Real-time PCR quantitation

Orthotopic or intracardiac injection of human breast cancer cell lines into immunocompromised mice allows study of the molecular basis of breast cancer metastasis. We have established a quantitative real-time PCR approach to analyze metastatic spread of human breast cancer cells inoculated into nude mice via these routes. We employed MDA-MB-231 human breast cancer cells genetically tagged with a bacterial β-galactosidase (Lac-Z) retroviral vector, enabling their detection by TaqMan® real-time PCR. PCR detection was linear, specific, more sensitive than conventional PCR, and could be used to directly quantitate metastatic burden in bone and soft organs. Attesting to the sensitivity and specificity of the PCR detection strategy, as few as several hundred metastatic MDA-MB-231 cells were detectable in 100 μm segments of paraffin-embedded lung tissue, and only in samples adjacent to sections that scored positive by histological detection. Moreover, the measured real-time PCR metastatic burden in the bone environment (mouse hind-limbs, n=48) displayed a high correlation to the degree of osteolytic damage observed by high resolution X-ray analysis (r 2=0.972). Such a direct linear relationship to tumor burden and bone damage substantiates the so-called `vicious cycle' hypothesis in which metastatic tumor cells promote the release of factors from the bone which continue to stimulate the tumor cells. The technique provides a useful tool for molecular and cellular analysis of human breast cancer metastasis to bone and soft organs, can easily be extended to other cell/marker/organ systems, and should also find application in preclinical assessment of anti-metastatic modalities.

Efeito antitumoral, genotóxico e mutagênico de nitensidina A em camundongos nude BALB/c com implante tumoral xenográfico de células imortalizadas com HPV-16 (SiHa)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)