Multi-modal image registration: matching MRI with histology

Spatial correspondence between histology and multi sequence MRI can provide information about the capabilities of non-invasive imaging to characterize cancerous tissue. However, shrinkage and deformation occurring during the excision of the tumor and the histological processing complicate the co registration of MR images with histological sections. This work proposes a methodology to establish a detailed 3D relation between histology sections and in vivo MRI tumor data. The key features of the methodology are a very dense histological sampling (up to 100 histology slices per tumor), mutual information based non-rigid B-spline registration, the utilization of the whole 3D data sets, and the exploitation of an intermediate ex vivo MRI. In this proof of concept paper, the methodology was applied to one tumor. We found that, after registration, the visual alignment of tumor borders and internal structures was fairly accurate. Utilizing the intermediate ex vivo MRI, it was possible to account for changes caused by the excision of the tumor: we observed a tumor expansion of 20%. Also the effects of fixation, dehydration and histological sectioning could be determined: 26% shrinkage of the tumor was found. The annotation of viable tissue, performed in histology and transformed to the in vivo MRI, matched clearly with high intensity regions in MRI. With this methodology, histological annotation can be directly related to the corresponding in vivo MRI. This is a vital step for the evaluation of the feasibility of multi-spectral MRI to depict histological ground-truth

Effect of low-close tumor necrosis factor-α in combination with STEALTH® liposomal cisplatin (SPI-077) on soft-tissue- and osteosarcoma-bearing rats

Cisplatin is a widely used agent for treatment of solid tumors, but its clinical utility is limited by toxicity. Preclinical studies have shown less acute toxicity when STEALTH® liposomal cisplatin (SPI-077) is used, with antitumor effects equivalent to those of intravenously administered free cisplatin. We previously reported that systemic treatment with low-dose tumor necrosis factor-α (TNF) augments the activity of STEALTH® liposomal doxorubicin (Doxil®). In this study, we examined the effect of repeated systemic applications of low-dose TNF on the antitumor activity of SPI-077 in rats with soft-tissue sarcoma or osteosarcoma. Addition of TNF to SPI-077 treatment showed an improved tumor growth delay of the soft-tissue sarcoma. The combined SPI-077/TNF treatment resulted in a more prolonged antitumor activity, whereas free cisplatin showed a better tumor response, however with a rapid outgrowth a few days after the end of therapy. In the osteosarcoma, free cisplatin did not have an antitumor effect, but addition of TNF caused a clear tumor growth delay. SPI-077 alone resulted in a tumor growth delay, but combination with TNF had no additive effect. SPI-077 yielded less systemic toxicity than cisplatin. Depending on the type of tumor, the addition of TNF to SPI-077 results in a better tumor growth delay with a prolonged antitumor effect and, in combination with the reduced toxicity of SPI-077, this combination may be preferable to cisplatin

Identification and characterization of the murine ortholog (brms1) of breast-cancer metastasis supressor 1 (BRMS1)

We have cloned a novel metastasis-suppressor gene (BRMS1) by differential display, comparing metastatic human breast carcinoma cell line MDA-MB-435 to its metastasis-suppressed human chromosome II microcell hybrid. Screening of a murine cDNA library led to the identification of a 1.4 kb cDNA with a sequence revealing 85% homology to human BRMS1 within the open reading frame. The predicted protein sequence for the murine ortholog is 95% identical, suggesting that it is strongly conserved across these 2 species. The cloned cDNA was used to screen a murine strain SV129 BAC library to obtain brms1 genomic DNA. Three BAC clones [226(14), 226(H4) and 239(N7)] were confirmed to encode the entire brms1 gene. Detailed analysis of BAC clone 226(14) shows that the gene spans 8.5 kb and, like the human gene, is organized into 10 exons and 9 introns. While the exons share a high degree of homology, there are greater differences when comparing intron structures between the human and murine genes. The 5′ upstream region shares about 64% homology with its human counterpart, retaining several of the many putative regulatory elements. Like the human genomic BRMS1, the murine ortholog of the iGnT gene is found upstream of brms1 and the murine ortholog of the RINI gene is found downstream of brms1. brms1 was then tested for suppression of metastasis of mouse mammary carcinoma cell line 66c14 in syngeneic BALB/c mice. Transfection with brms1 did not inhibit 66c14 primary tumor formation but significantly suppressed its metastatic capability. This suggests that the murine ortholog functions similarly to BRMS1

Biodistribution and tumor localization of stealth liposomal tumor necrosis factor-α in soft tissue sarcoma bearing rats

The blood residence half-life and organ distribution of recombinant human tumor necrosis factor-α (TNF-α) encapsulated in sterically stabilized liposomes, were investigated in rats bearing a soft tissue sarcoma in the hind leg. We studied the decay in blood concentration of 'empty' liposomes using the aqueous marker 67gallium-desferal, as well as the blood concentration of soluble TNF-α and liposome encapsulated TNF-α using 125I. Encapsulation efficacy of TNF-α was 24%. The pharmacokinetics of TNF-α were markedly altered after encapsulation in liposomes, with a 33- fold increase in mean residence time of TNF-α in the blood, and a concomitant 14-fold increase in the area under the plasma concentration vs. time curve for liposomal TNF-α. Although the liposomes exhibit Stealth characteristics, uptake by mononuclear phagocyte-rich organs (e.g., liver and spleen) was noticeable, especially at later time points. Encapsulation of TNF-α in sterically stabilized liposomes resulted in a marked increase in localization of the cytokine in tumor measured as total uptake over time. However, peak TNF-α concentration levels in tumor were not significantly enhanced compared with free TNF-α. Besides the augmented localization of TNF-α after encapsulation in sterically stabilized liposomes, a diminished toxicity was observed

Identification and characterization of the murine ortholog (brms1) of breast-cancer metastasis supressor 1 (BRMS1)

We have cloned a novel metastasis-suppressor gene (BRMS1) by differential display, comparing metastatic human breast carcinoma cell line MDA-MB-435 to its metastasis-suppressed human chromosome II microcell hybrid. Screening of a murine cDNA library led to the identification of a 1.4 kb cDNA with a sequence revealing 85% homology to human BRMS1 within the open reading frame. The predicted protein sequence for the murine ortholog is 95% identical, suggesting that it is strongly conserved across these 2 species. The cloned cDNA was used to screen a murine strain SV129 BAC library to obtain brms1 genomic DNA. Three BAC clones [226(14), 226(H4) and 239(N7)] were confirmed to encode the entire brms1 gene. Detailed analysis of BAC clone 226(14) shows that the gene spans 8.5 kb and, like the human gene, is organized into 10 exons and 9 introns. While the exons share a high degree of homology, there are greater differences when comparing intron structures between the human and murine genes. The 5′ upstream region shares about 64% homology with its human counterpart, retaining several of the many putative regulatory elements. Like the human genomic BRMS1, the murine ortholog of the iGnT gene is found upstream of brms1 and the murine ortholog of the RINI gene is found downstream of brms1. brms1 was then tested for suppression of metastasis of mouse mammary carcinoma cell line 66c14 in syngeneic BALB/c mice. Transfection with brms1 did not inhibit 66c14 primary tumor formation but significantly suppressed its metastatic capability. This suggests that the murine ortholog functions similarly to BRMS1.</p