Histopathological predictors of regional lymph node metastasis at the invasive front in early colorectal cancer.

AIMS: In early colorectal cancer (ECC), prediction of lymph node (LN) metastasis is vital for the decision of additional surgical treatment after endoscopic mucosal/submucosal resection. The aim of this study was to determine the relationship between LN metastasis and comprehensive histopathological findings including the cancer microenvironment in ECC. METHODS AND RESULTS: Using 111 ECC cases, including 36 cases with LN metastasis, histopathological observations and immunohistochemistry for lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), von Willebrand factor, matrix metalloproteinase-7 (MMP-7), CXC chemokine ligand-12 (CXCL12) and angiopoietin-like-4 (ANGPTL4) were conducted. Relationships between LN metastasis and growth pattern, status of muscularis mucosae, depth of cancer invasion, overall histopathological type, histopathological type at the invasive front, tumour budding, neutrophil infiltration in cancer cells (NIC), fibrotic cancer-stroma type, Crohn's-like lymphoid reaction, microscopic abscess formation and lymphatic invasion were determined. In addition, the expression of MMP-7, CXCL12 and ANGPTL4 in cancer cells at the invasive front were also considered in the context of LN metastasis. By multivariate analysis, lymphatic invasion, NIC and MMP-7 expression at the invasive front were independent predictors of LN metastasis. CONCLUSIONS: LN metastasis is regulated not only by the characteristics of cancer cells but also by microenvironmental factors of lymphatics and neutrophils, especially at the invasive front.

The mechanisms underlying fibroblast apoptosis regulated by growth factors during wound healing.

While investigating the mechanisms underlying cell death during wound healing processes, we uncovered the pro-apoptotic effects of basic fibroblast growth factor (bFGF) on granulation tissue fibroblasts following pretreatment with transforming growth factor (TGF)-beta1 in vitro. bFGF induced caspase-3 activation and apoptosis in TGF-beta1-pretreated granulation tissue-derived fibroblasts (GF-1) following bFGF treatment for 48 and 96 h. In contrast, fibroblasts that had been treated in the same manner and that originated from the uninjured dermis did not display apoptosis, indicating that the mechanisms underlying apoptosis events in fibroblasts that originate from normal dermal and wound tissues differ. In this process, we also found that bFGF inhibited Akt phosphorylation at serine 473 and induced a rapid loss of phosphorylation of focal adhesion kinase (FAK) at tyrosine 397 in pretreated GF-1 cells, an event that coincided with the dissociation of phosphorylated FAK from the focal adhesions. Therefore, inhibition of survival signals relayed via the disrupted focal adhesion structures and inactivated Akt following bFGF treatment may lead to apoptosis in GF-1 cells pretreated with TGF-beta1. Pretreatment of GF-1 with TGF-beta1 followed by the addition of bFGF resulted in significantly greater inhibition of phosphorylation of Akt and FAK compared to treatment with TGF-beta1 or bFGF alone. The combinatorial treatment also led to proteolysis of FAK and inhibition of FAK and Akt protein expression in GF-1 cells. These findings demonstrated a significant role for the two cytokines in apoptosis of granulation tissue fibroblasts during wound healing. In vivo studies also confirmed a marked decline in phosphorylation and protein expression of Akt and FAK in bFGF-injected skin wounds. These results led to the hypothesis that temporal activation of TGF-beta1 and bFGF at the injury site promotes apoptosis in granulation tissue fibroblasts, an event that is critical for the termination of proliferative granulation tissue formation.

Promoted activation of matrix metalloproteinase (MMP)-2 in keloid fibroblasts and increased expression of MMP-2 in collagen bundle regions: implications for mechanisms of keloid progression.

AIMS: Keloid is characterized by excessive deposition of collagen, resulting from aberrant extracellular matrix (ECM) production and degradation. The aim was to investigate the role of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in pathological wound healing in keloids. METHODS AND RESULTS: Semiquantitative analysis of 60 keloid tissue samples and 25 mature scar tissue samples demonstrated significantly increased expression of MMP-2, TIMP-2 and TIMP-3 in keloids compared with mature scars. Within keloid regions, MMP-2 expression was significantly higher in collagen bundle regions than in non-collagen bundle regions. Double immunofluorescence revealed that keloid fibroblasts between collagen bundles exhibited MMP-2, TIMP-2 and membrane-type 1 MMP (MT1-MMP) co-expression, whereas only MMP-2 expression was evident on the edge of collagen bundles. Western blot analysis and gelatin zymography of 13 keloid-derived fibroblasts (KFbs) and six normal skin dermal-derived fibroblasts (NFbs) demonstrated that unstimulated KFbs exhibited significantly increased MMP-2 activity and expression compared with NFbs under the same conditions. CONCLUSIONS: These results together indicate that MMP-2 activity can be promoted in keloid fibroblasts between collagen bundles in cooperation with TIMP-2 and MT1-MMP. This could contribute to remodelling of collagen bundle regions and invasion of fibroblasts into peripheral normal regions through promoted degradation of ECM.

The optimal reconstruction size of nipple-areola complex following breast implant in breast cancer patients.

BACKGROUND: Changes in the areola size after reconstruction of the nipple-areola complex (NAC) following mastectomy and breast reconstruction with a silicon implant in primary breast cancer patients have not been well examined. This study aimed to investigate time-dependent changes in the size of the donor and graft NACs and to assess clinical factors influencing these changes. METHODS: Fifty-eight consecutive patients who underwent nipple-areola reconstruction were retrospectively evaluated. Nipple-areola diameter was measured immediately after the NAC reconstruction and at each follow-up visit for at least 36 months. RESULTS: The donor NAC constituted 81 % of the graft NAC at the time of operation. The size of the donor NAC gradually increased by up to 36.8 % after the operation. The size of the graft NAC showed a decrease by 4.5 % at 7 months, followed by recovery to the initial value. The ratio of the donor site size to the graft site size was increased at month 1 and then showed a gradual decrease to 1.08 at 36 months. A history of mastopexy or reduction for the donor site was independent factors associated with changes in the NAC size. CONCLUSIONS: To achieve symmetry, the diameter of the donor NAC immediately after the reconstruction should be at least 20 % smaller than that of the graft NAC, especially for patients without a history of additional operations.

Antifibrotic response of cardiac fibroblasts in hypertensive hearts through enhanced TIMP-1 expression by basic fibroblast growth factor.

BACKGROUND: Cardiac fibroblasts (CFs) play a pivotal role in the development of myocardial fibrosis. We previously demonstrated that direct injection of basic fibroblast growth factor (bFGF) into the hypertensive Dahl salt-sensitive (DS) rat heart prevented systolic dysfunction and left ventricular dilation effectively. However, the precise role played by bFGF in fibrotic response of CFs remains unclear. We suggested potential effects of bFGF on the fibrotic response of CFs in vitro. METHODS AND RESULTS: Histopathologic assessment of cardiac fibrosis demonstrated a marked decline in the extent of perivascular and interstitial fibrosis in bFGF-injected hypertensive DS rat hearts. CFs harvested from the hearts of noninjected DS rats demonstrated a significantly increased messenger RNA (mRNA) expression of matrix metalloproteinase (MMP)-2, MMP-9, and both collagen I and III. In contrast, bFGF treatment in the CFs induced a marked increase in tissue inhibitor of MMP (TIMP)-1 expression and a marked decline in MMP-9 activation. bFGF also induced a decline in α-smooth muscle actin and collagen I and III mRNA expression in the CFs accompanied by inhibited differentiation of CFs into myofibroblasts. Small interfering RNA targeting FGF receptor 1 confirmed a specific interference of the mRNA expression changes elicited by bFGF. In vivo examination confirmed many TIMP-1-positive CFs in perivascular spaces of bFGF-injected hearts. CONCLUSIONS: Up-regulated TIMP-1 expression and down-regulated MMP-9 activation by bFGF in CFs could prevent excessive ECM degradation and collagen deposition in perivascular spaces effectively, leading to prevention of cardiac fibrosis during hypertensive heart failure. SUMMARY: Cardiac fibroblasts (CFs) play a pivotal role in myocardial fibrosis. The precise role of CFs in fibrotic response played by growth factors remains unclear. Our results indicates that basic fibroblast growth factor could up-regulate TIMP-1 expression and down-regulate MMP-9 activation in CFs in perivascular spaces, leading to inhibited progression of cardiac fibrosis during hypertensive heart failure.

Distribution of smooth muscle cells and macrophages expressing scavenger receptor BI/II in atherosclerosis.

AIM: Scavenger receptors type I and II (SRBI/II) have dual roles in both atherogenic and antiatherogenic functions through interactions with lipoproteins and their expression in macrophages; how-ever, the distribution and density of SRBI/II-positive macrophages and smooth muscle cells (SMCs) as well as their association with lipid metabolism-related proteins in atherosclerotic intima of the human aorta remain unclear. METHODS: Autopsied aortic tissues were double-immunostained with SRBI/BII and smooth muscle actin or macrophage-specific antibodies. The density of SRBI/BII-positive SMCs and macrophages in intimal lesion was measured. They were also immunostained with antibodies against four apolipoproteins, four phospholipase A2s, and CETP. RESULTS: SRBI/II was expressed in both macrophages and SMCs distributed in various intimal lesions. The density of SRBI/II-positive SMCs in intimal lesions significantly decreased with the advance of atherosclerosis, whereas the density of SRBI/II-positive macrophages significantly increased with atherosclerotic development. In addition, functional proteins, such as apolipoproteins, secretory phospholipase A2s, and CETP, were distributed in the intimal stroma around SRBI/II-positive cells in all lesion types. CONCLUSION: The results indicated that SMCs are involved in lipid metabolism via SRBI/II expression mainly in the early stages of atherosclerosis evolution, and that SRBI/II-positive macrophages are mainly involved in advanced stages.