Potential for Tumorigenesis and Repair of Osteochondral Defects by iPS Cell Transplantation in Rat

Abstract Articular cartilage repair remains a challenge in the field of orthopedic medicine. Cell-based therapy for cartilage repair, such as autologous chondrocyte implantation, was established in the 1990s. However, the issue of the source from which the lesion-targeting cells are harvested remains a limitation of this approach as larger lesions require more cells for repair, and thus, more healthy tissue must be damaged to harvest the needed cells. Reprogramming of induced pluripotent stem (iPS) cells is a promising tool for cell-based regenerative therapy because of their proliferative capacity and pluripotency; however, these characteristics also create a risk of tumorigenesis. This study aimed to determine the probability of iPS cell-derived tumor occurrence as a function of injection or transplantation site, and to assess whether transplanted iPS cells can promote cartilage defect repair. Pluripotent mouse iPS cells (5x10 6 cells/ml) were subcutaneously injected or transplanted into experimentally induced lesions in the knee cartilage of immunodeficient rats. Subcutaneous teratoma formation was observed in 30% of animals (3 of 10) at 4weeks, and 41% of animals (7 of 17) at 12 weeks after iPS cell injection. Cartilage repair as indicated by modified Wakitani's score was similar in the cell-free group and in the iPS cell implantation group at 4 weeks [11.8 ± 1.8 (n = 8) vs. 10.3 ± 2.8 (n = 18)]. iPS cell implantation yielded a score of 7.8 ± 2.0 (n = 10) at 12 weeks, significantly better than the cell-free group [10.5 ± 0.6 (n = 4)]. There was no macro-or microscopic evidence of tumor formation at the cartilage repair site after iPS cell implantation. Although we could not use the iPS cells directly for cartilage repair, the results of our study indicate the potential for a new therapy for cartilage repair by developing iPS reprogramming technology

Localization of oxytalan fiber, type III collagen and BMP family in conventional and desmoplastic ameloblastoma

The histologic hallmark distinguishing desmoplastic ameloblastoma (DA) from conventional ameloblastoma (CA) is its pronounced stromal desmoplasia, and this formed the basis of this investigation. To elucidate the stromal characteristics, localization patterns of oxytalan fibers, type III collagen and BMP family in DA (n=8) was compared with CA (n=24), and periodontal ligament (PL) (n=8). Oxytalan fibers formed apico-occlusal bundles in PL, thick radial bundles around tumor nests in DA, and as scanty fibers in CA. Type III collagen was identified in PL, strongly expressed in DA stroma, but weakly in CA. BMP-2, -3, -4 and -7 expression patterns in tumor epithelium and stroma were more pronounced in DA (including sites of bone formation), than CA. No immunoreactivity for BMP-5 and -6 were detected. Current findings suggest that the stroma in DA is neoplastic and derived from odontogenic ectomesenchyme, and recommends its reclassification as an odontogenic epithelial-ectomesenchymal neoplasm

Invasive characteristics of human prostatic epithelial cells: understanding the metastatic process

Prostate cancer has a predilection to metastasise to the bone marrow stroma (BMS) by an as yet uncharacterised mechanism. We have defined a series of coculture models of invasion, which simulate the blood/BMS boundary and allow the elucidation of the signalling and mechanics of trans-endothelial migration within the complex bone marrow environment. Confocal microscopy shows that prostate epithelial cells bind specifically to bone marrow endothelial-to-endothelial cell junctions and initiate endothelial cell retraction. Trans-endothelial migration proceeds via an epithelial cell pseudopodial process, with complete epithelial migration occurring after 232±43 min. Stromal-derived factor-1 (SDF-1)/CXCR4 signalling induced PC-3 to invade across a basement membrane although the level of invasion was 3.5-fold less than invasion towards BMS (P=0.0007) or bone marrow endothelial cells (P=0.004). Maximal SDF-1 signalling of invasion was completely inhibited by 10 μM of the SDF-1 inhibitor T140. However, 10 μM T140 only reduced invasion towards BMS and bone marrow endothelial cells by 59% (P=0.001) and 29% (P=0.011), respectively. This study highlights the need to examine the potential roles of signalling molecules and/or inhibitors, not just in single-cell models but in coculture models that mimic the complex environment of the bone marrow

Crosstalk between Chemokine Receptor CXCR4 and Cannabinoid Receptor CB2 in Modulating Breast Cancer Growth and Invasion

Cannabinoids bind to cannabinoid receptors CB(1) and CB(2) and have been reported to possess anti-tumorigenic activity in various cancers. However, the mechanisms through which cannabinoids modulate tumor growth are not well known. In this study, we report that a synthetic non-psychoactive cannabinoid that specifically binds to cannabinoid receptor CB(2) may modulate breast tumor growth and metastasis by inhibiting signaling of the chemokine receptor CXCR4 and its ligand CXCL12. This signaling pathway has been shown to play an important role in regulating breast cancer progression and metastasis.We observed high expression of both CB(2) and CXCR4 receptors in breast cancer patient tissues by immunohistochemical analysis. We further found that CB(2)-specific agonist JWH-015 inhibits the CXCL12-induced chemotaxis and wound healing of MCF7 overexpressing CXCR4 (MCF7/CXCR4), highly metastatic clone of MDA-MB-231 (SCP2) and NT 2.5 cells (derived from MMTV-neu) by using chemotactic and wound healing assays. Elucidation of the molecular mechanisms using various biochemical techniques and confocal microscopy revealed that JWH-015 treatment inhibited CXCL12-induced P44/P42 ERK activation, cytoskeletal focal adhesion and stress fiber formation, which play a critical role in breast cancer invasion and metastasis. In addition, we have shown that JWH-015 significantly inhibits orthotopic tumor growth in syngenic mice in vivo using NT 2.5 cells. Furthermore, our studies have revealed that JWH-015 significantly inhibits phosphorylation of CXCR4 and its downstream signaling in vivo in orthotopic and spontaneous breast cancer MMTV-PyMT mouse model systems.This study provides novel insights into the crosstalk between CB(2) and CXCR4/CXCL12-signaling pathways in the modulation of breast tumor growth and metastasis. Furthermore, these studies indicate that CB(2) receptors could be used for developing innovative therapeutic strategies against breast cancer

A pigmented calcifying cystic odontogenic tumor associated with compound odontoma: a case report and review of literature

<p>Abstract</p> <p>Background</p> <p>Pigmented intraosseous odontogenic lesions are rare with only 47 reported cases in the English literature. Among them, pigmented calcifying cystic odontogenic tumor, formerly known as calcifying odontogenic cyst, is the most common lesion with 20 reported cases.</p> <p>Methods</p> <p>A case of pigmented calcifying cystic odontogenic tumor associated with odontoma occurring at the mandibular canine-premolar region of a young Japanese boy is presented with radiographic, and histological findings. Special staining, electron microscopic study and immunohistochemical staining were also done to characterize the pigmentation.</p> <p>Results</p> <p>The pigments in the lesion were confirmed to be melanin by Masson-Fontana staining and by transmission electron microscopy. The presence of dendritic melanocytes within the lesion was also demonstrated by S-100 immunostaining.</p> <p>Conclusion</p> <p>The present case report of pigmented calcifying cystic odontogenic tumor associated with odontoma features a comprehensive study on melanin and melanocytes, including histochemical, immunohistochemical and transmission electron microscopic findings.</p

A spindle cell carcinoma presenting with osseous metaplasia in the gingiva: a case report with immunohistochemical analysis

<p>Abstract</p> <p>Background</p> <p>Spindle cell carcinoma (SpCC) is a rare, high malignant variant of squamous cell carcinoma (SCC), which shows biphasic proliferation of conventional SCC component and malignant spindle shape cells with sarcomatous appearance.</p> <p>Methods</p> <p>A case of Spindle cell carcinoma with bone-like calcified materials, occurring at the mandibular molar region of 71-years-old Japanese male patient was presented with gross finding, histological findings and MRI image. To identify the characteristics of the bone-like materials, immunohistochemistry were performed.</p> <p>Results</p> <p>Histologically, the cancer cells were composed of spindle cells and epithelial cells which form nests with prominent keratinization. Histological findings showed typical histology of the SpCC, however, as an uncommon finding, spatters of calcified, bone-like materials were observed in between the cancer cells. Immunohistochemistry revealed that cancer cells were positive for cytokeratins and vimentin to a varying degree and negative for Desmin, S-100, Osteopontin, BMP-2 or BMP-4. These findings implied that the calcified materials were formed by metaplasia of the stromal cells.</p> <p>Discussion</p> <p>Bone-like materials formation by osseous and/or cartilaginous metaplasia of the stroma in the carcinoma has been reported. However, the detailed mechanism of these metaplasia and affection on the clinical feature, prognosis and therapies are not well established. In summary, we presented an unique case of SpCC, which has not been described in the literature.</p

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes

The Chemokine Receptor CXCR4 Strongly Promotes Neuroblastoma Primary Tumour and Metastatic Growth, but not Invasion

Neuroblastoma (NB) is a heterogeneous, and particularly malignant childhood neoplasm in its higher stages, with a propensity to form metastasis in selected organs, in particular liver and bone marrow, and for which there is still no efficient treatment available beyond surgery. Recent evidence indicates that the CXCR4/CXCL12 chemokine/receptor axis may be involved in promoting NB invasion and metastasis. In this study, we explored the potential role of CXCR4 in the malignant behaviour of NB, using a combination of in vitro functional analyses and in vivo growth and metastasis assessment in an orthotopic NB mouse model. We show here that CXCR4 overexpression in non-metastatic CXCR4-negative NB cells IGR-NB8 and in moderately metastatic, CXCR4 expressing NB cells IGR-N91, strongly increased tumour growth of primary tumours and liver metastases, without altering the frequency or the pattern of metastasis. Moreover shRNA-mediated knock-down experiments confirmed our observations by showing that silencing CXCR4 in NB cells impairs in vitro and almost abrogates in vivo growth. High levels of CXCL12 were detected in the mouse adrenal gland (the primary tumour site), and in the liver suggesting a paracrine effect of host-derived CXCL12 on NB growth. In conclusion, this study reveals a yet unreported NB-specific predominant growth and survival-promoting role of CXCR4, which warrants a critical reconsideration of the role of CXCR4 in the malignant behaviour of NB and other cancers

Alternative implication of CXCR4 in JAK2/STAT3 activation in small cell lung cancer

Small cell lung cancer (SCLC) is an aggressive, rapidly metastasising tumour. Previously, we demonstrated the influence of CXCL12–CXCR4 interaction on processes involved in metastasis and chemoresistance in SCLC. We show here that STAT3 is expressed in both primary SCLC tumour tissues and SCLC cell lines. We investigated the function of STAT3 upon CXCL12 stimulation in SCLC cell lines. Small cell lung cancer cell lines present constitutive phosphorylation of STAT3, and in the reference cell lines NCI-H69 and NCI-H82 constitutive phosphorylation was further increased by CXCL12 stimulation. Further investigating this signalling cascade, we showed that it involves interactions between CXCR4 and JAK2 in both cell lines. However CXCL12-induced adhesion to VCAM-1 could be completely inhibited by the JAK2 inhibitor AG490 only in NCI-H82. Furthermore, CXCR4 antagonist but not AG490 inhibited cell adhesion whereas both antagonisms were shown to inhibit growth of the cells in soft agar, indicating the central involvement of this signalling in anchorage-independent growth of SCLC cells. Most interestingly, while using primary tumour material, we observed that in contrast to non-small-cell lung cancer samples from primary tumour tissues, all analysed samples from SCLC were strongly positive for tyrosine-phosphorylated STAT3. Taken together, these data indicate that STAT3 is constitutively phosphorylated in SCLC and is important in SCLC growth and spreading thus presenting an interesting target for therapy