Cancer chemotherapy targeted to angiogenic vessels is expected to cause indirect tumor regression through the damage of the neovasculature without the induction of drug resistance. To develop a tool for neovasculaturespeci®c drug delivery, we isolated novel peptides homing to angiogenic vessels formed by a dorsal air sac method from a phage-displayed peptide library. Three distinct phage clones that markedly accumulated in murine tumor xenografts presented PRPGAPLAGSWPGTS-, DRWRPALPVVLFPLH-or ASSSYPLIHWRPWARpeptide respectively. After the determination of the epitope sequences of these peptides, we modi®ed liposomes with epitope penta-peptides. Liposome modi®ed with APRPG-peptide showed high accumulation in murine tumor xenografts, and APRPG-modi®ed liposome encapsulating adriamycin eectively suppressed experimental tumor growth. Finally, speci®c binding of APRPG-modi®ed liposome to human umbilical endothelial cells, and that of PRP-containing peptide to angiogenic vessels in human tumors, i.e., islet cell tumor and glioblastoma, were demonstrated. The present study indicates the usefulness of APRPG-peptide as a tool for anti-neovascular therapy, a novel modality of cancer treatment.

DNA hypermethylated gene promoter sequences are extremely promising cancer markers. Their use for risk assessment, early diagnosis, or prognosis depends on the timing of this gene change during tumor progression. We studied this for the proapoptotic gene ASC/TMS1 in lung cancer and used the findings to develop a sputum marker. ASC/TMS1 protein levels are reduced in all lung cancer types (30 of 40; 75%) but not in 10 preinvasive lesions. Hypermethylation of ASC/TMS1 is also associated with invasive cancers (41 of 152 or 27.0% of all lung cancer types) with variation in incidence between histopathologic types including 32.1% (26 of 81) of adenocarcinomas, 13.2% (7 of 53) of squamous cell carcinomas, 38.5% (5 of 13) of large-cell carcinomas, and 60% (3 of 5) of small-cell lung cancers. The hypermethylation is particularly correlated with late tumor stages being present in only 14% of stage I but 60% of later-stage tumors. The incidence of ASC/TMS1 hypermethylation in sputum DNA fully mimics the tissue findings being present in only 2% (2 of 85) of high-risk, cancerfree smokers, 15% (3 of 18) of patients with stage I non-smallcell lung cancer (NSCLC), but 41% of patients with stage III NSCLC (18 of 44), including 56% (10 of 18) of those with adenocarcinoma. Importantly, sputum is positive for this marker in 24% (10 of 42) of very high risk, clinically cancerfree individuals previously resected for stage I NSCLC. Thus, hypermethylation of ASC/TMS1 is a marker for late-stage lung cancer and, in sputum, could predict prognosis in patients resected for early-stage disease. (Cancer Res 2006; 66(12): 6210-8)

Cell surface carbohydrates expressed on epithelial cells are thought to play an important role in tumor progression. Previously, we have shown that expression of core 2-branched O-glycans is closely correlated with vessel invasion and depth of invasion in colon and lung carcinomas. In this study, we found that expression of core 2 beta1,6-N-acetylglucosaminyltransferase-1, Core2GnT, is positively correlated with the progression of prostate cancer in human patients. Statistical analysis demonstrated that Core2GnT is an independent predictor for progressed pathological stage (pT3) and for prostate-specific antigen (PSA) relapse. To determine directly the roles of Core2GnT in prostate cancer progression, we set up an experimental tumor model using the LNCaP prostate cancer cell line. Because this line does not express Core2GnT, we established an LNCaP line stably expressing Core2GnT, LNCap-Core2GnT, by transfecting cDNA encoding Core2GnT. When mock-transfected LNCaP cells and LNCaP-Core2GnT were inoculated in the prostate of nude mice, LNCaP-Core2GnT cells produced three times heavier prostate tumors than mock-transfected LNCaP cells. Furthermore, we found that LNCaP-Core2GnT cells adhered more strongly to prostate stromal cells, type IV collagen and laminin than did LNCaP-mock cells, but LNCaP and LNCaP-Core2GnT cells grew almost at the same rate on plates coated with type IV collagen or laminin. These results indicate that Core2GnT is an extremely useful prognostic marker for prostate cancer progression. The results also suggest that acquiring Core2GnT in prostate carcinoma cells facilitates adhesion to type IV collagen and laminin, and this increased adhesion may be a cause for aggressive tumor formation by prostate cancer cells expressing Core2GnT.

Purpose: Gliomas are common tumors of the central nervous system, and the majority of patients with gliomas have a poor prognosis. The prediction of prognosis is very important in selecting treatment. In the present study, we retrospectively examined the immunohistochemical staining of cleaved caspase-3 (CC3), an activated form of caspase-3 that acts as a lethal protease at the most distal stage of the apoptosis pathway, in gliomas, and the correlation between the prognosis of patients and caspase-3 activation to find useful prognostic indicators. Experimental Design: Immunohistochemical staining of CC3 was done in 65 patients with gliomas. The percentage of CC3 staining-positive cells was defined as the CC3 immunoreactivity score (IRS). Survival analysis between CC3 IRS of glioma patients and survival time was carried out using the Kaplan-Meier method with the log-rank test and the Cox proportional hazards regression model. Results: CC3 IRS was statistically analyzed to designate the best provisional cutoff point, and when detected in >10% of glioma cells, it was considered positive.The Kaplan-Meier method with the log-rank test revealed that patients with CC3 IRS-positive tumors had significantly greater survival than those with CC3 IRS-negative tumors among three grades, 2, 3, and 4 (P = 0.0061), and within grade 3 of anaplastic astrocytoma (P = 0.0458). After adjustment for known clinical prognostic factors, such as age, WHO grade, and performance status, the hazard ratio for CC3 IRS-positive was 0.39 with 95% confidence interval between 0.19 and 0.85 (P = 0.0187). Within high grades, including grades 3 and 4, the hazard ratio was 0.40 with 95% confidence interval between 0.20 and 0.86 (P = 0.0192). Conclusions: CC3 IRS could be useful as a good prognostic indicator for glioma patients.

Bone is one of the most common metastatic sites of breast cancer, and bone metastasis profoundly affects the quality of life of breast cancer patients. Bone metastasis is commonly observed among all the subtypes of breast cancer; however, its molecular mechanism has been analyzed only in triple‐negative subtype of breast cancer (TNBC). To characterize the molecular mechanisms of bone metastasis of luminal breast cancer, we established a bone‐metastatic model of the MCF7, luminal breast cancer cell line, with enhanced osteolytic activity by intracaudal arterial injection (CAI). Pathological analysis of the established cell lines revealed that they exhibited fierce osteolytic ability by promoting osteoclast differentiation and activity. The signature genes extracted from highly osteolytic MCF7 cell lines were differed from those of bone‐metastatic TNBC cell lines. Our results suggest that unique mechanisms of osteolysis in bone‐metastatic lesions of luminal breast cancer. In addition, several up‐regulated genes in MCF7‐BM (Bone Metastasis) 02 cell lines correlated with poor prognosis with luminal breast cancer patients. Our findings support further study on the bone‐metastatic mechanisms of luminal breast cancer.

Metastasis signature genes in breast cancer have been studied comparing transcriptomic profiles of highly metastatic cancer cell lines established by intra-circulation injection with that of their parental cell line. However, this method is not suitable to analyze the initial steps of metastasis including invasion into local tissues and the circulatory system. To characterize the molecular mechanisms of early metastasis, we established highly metastatic MDA-MB-231 cell lines that metastasized to lung by the two animal transplantation models: the orthotopic transplantation method, which mimics all steps of metastasis, or intra-circulation injection method. We then performed data-mining and network analysis of gene expression profiles of metastatic cell lines established by each transplantation method. Transcriptome analysis of seven metastatic cell lines revealed novel lung metastasis signature genes, including known metastasis promoting genes and signature genes. In the OXconc (orthotopic xenograft concentration) signature, 'chemotaxis' and 'cell adhesion' terms were enriched. In the TVIconc (tail vein injection concentration) signature, 'antigen recognition' and 'cell adhesion' were enriched. Furthermore, network analysis of the metastasis signature genes highlighted hub genes in the gene regulatory network. Our findings show that expression profiles of highly metastatic cell lines were different between the orthotopic transplantation and intra-circulation injection method. It also indicates that some metastatic signature genes have been missed in previous studies. Characterization of metastasis genes using the orthotopic transplantation method will be helpful in understanding the multi-step mechanisms of metastasis. Signature genes in OXconc may have the potential to become prognostic markers.

Rho GTPase Rac1 is a central regulator of F‐actin organization and signal transduction to control plasma membrane dynamics and cell proliferation. Dysregulated Rac1 activity is often observed in various cancers including breast cancer and is suggested to be critical for malignancy. Here, we showed that the ubiquitin E3 ligase complex Cullin‐3 (CUL3)/KCTD10 is essential for epidermal growth factor (EGF)‐induced/human epidermal growth factor receptor 2 (HER2)‐dependent Rac1 activation in HER2‐positive breast cancer cells. EGF‐induced dorsal membrane ruffle formation and cell proliferation that depends on both Rac1 and HER2 were suppressed in CUL3‐ or KCTD10‐depleted cells. Mechanistically, CUL3/KCTD10 ubiquitinated RhoB for degradation, another Rho GTPase that inhibits Rac1 activation at the plasma membrane by suppressing endosome‐to‐plasma membrane traffic of Rac1. In HER2‐positive breast cancers, high expression of Rac1 mRNA significantly correlated with poor prognosis of the patients. This study shows that this novel molecular axis (CUL3/KCTD10/RhoB) positively regulates the activity of Rac1 in HER2‐positive breast cancers, and our findings may lead to new treatment options for HER2‐ and Rac1‐positive breast cancers.

Yes-associated protein (YAP) is a recently discovered growth-promoting transcription coactivator that has been shown to regulate the malignancy of various cancers. How YAP is regulated is not fully understood. Here, we show that one of the factors regulating YAP is phosphatidylserine (PS) in recycling endosomes (REs). We use proximity biotinylation to find proteins proximal to PS. Among these proteins are YAP and multiple proteins related to YAP signalling. Knockdown of ATP8A1 (an RE PS-flippase) or evectin-2 (an RE-resident protein) and masking of PS in the cytoplasmic leaflet of membranes, all suppress nuclear localization of YAP and YAP-dependent transcription. ATP8A1 knockdown increases the phosphorylated (activated) form of Lats1 that phosphorylates and inactivates YAP, whereas evectin-2 knockdown reduces the ubiquitination and increased the level of Lats1. The proliferation of YAP-dependent metastatic cancer cells is suppressed by knockdown of ATP8A1 or evectin-2. These results suggest a link between a membrane phospholipid and cell proliferation.