Effect of pulsed electromagnetic field on MMP-9 and TIMP-1 levels in chondrosarcoma cells stimulated with IL-1ß.

Chondrosarcoma, the second most common type of bone malignancy, is characterized by distant metastasis and local invasion. Previous studies have shown that treatment by pulsed electromagnetic field (PEMF) has beneficial effects on various cancer cells. In this study, we investigated the effects of PEMF applied for 3 and 7 days on the matrix metalloproteinase (MMP) levels in chondrosarcoma SW1353 cells stimulated with two different doses of IL-1ß. SW1353 cells were treated with (0.5 and 5 ng/ml) IL-1ß and PEMF exposure was applied either 3 or 7 days. MMP-9 and TIMP-1 levels were measured in conditioned media by enzyme-linked immunosorbent assay. The results were relative to protein levels. Statistical analyses were performed using one-way analysis of variance (ANOVA). P<0.05 was considered significant. PEMF treatment significantly decreased MMP-9 protein levels in human chondrosarcoma cells stimulated with 0.5 ng/ml IL-1ß at day 7, whereas it did not show any effect on cells stimulated with 5 ng/ml IL-1ß. There was no significant change in TIMP-1 protein levels either by IL-1ß stimulation or by PEMF treatment. The results of this study showed that PEMF treatment suppressed IL-1ß-mediated upregulation of MMP-9 protein levels in a dual effect manner. This finding may offer new perspectives in the therapy of bone cancer.

Effects of intense pulsed light and ultraviolet A on metalloproteinases and extracellular matrix expression in human skin.

OBJECTIVE: The aim of this study was to evaluate the effects of intense pulsed light (IPL) and ultraviolet A (UVA) irradiation on the expression of matrix metalloproteases (MMPs), tissue inhibitor of metalloproteinase 1 (TIMP-1), and extracellular matrix (ECM) in human skin, and to confirm the relative mechanism. BACKGROUND DATA: IPL has been widely used to treat photoaged skin but the underlying mechanism remains unknown. METHODS: Human buttock skin was irradiated by repetitive suberythemal doses of UVA and therapeutic doses of IPL. Skin biopsies were taken and the protein/mRNA expression of MMP-1, -3, -9, and -12 and TIMP-1 was examined by immunohistochemistry, image analysis, and real-time quantitative polymerase chain reaction (qRT-PCR). RESULTS: Compared with normal control skin, both IPL and UVA irradiation induced a general elevation of MMP-1, -3, -9, and -12 and TIMP-1 at protein/mRNA levels, with some differences in the MMP expression patterns, e.g., a remarkable increase of MMP-1, -3, and -12 in UVA-exposed skin, while lower MMP-1, -3, and -12 (p < 0.01, p < 0.01, p < 0.01) but higher MMP-9 (p < 0.05) levels in IPL-irradiated skin. Meanwhile, increased collagen I fibers (p < 0.05) were observed in IPL-irradiated skin, whereas fragments of elastic fibers were found in UVA-exposed skin. CONCLUSION: These findings demonstrated that IPL has similar effects on the expression of MMPs/TIMP-1 in human skin to UVA, but the expression pattern differed from that in UVA-exposed skin, which may account for IPL's photorejuvenation effects.

Late changes in cutaneous gene expression patterns after adjuvant treatment of oral squamous cell carcinoma (OSCC) by radiation therapy.

OBJECTIVE: The objective of this study was to investigate radiation-induced late changes in cutaneous gene expression using a microarray platform and quantitative, real-time, reverse-transcriptase polymerase chain reaction (RT-PCR) validation. STUDY DESIGN: Paired irradiated and nonirradiated skin biopsies were obtained from 19 patients with a history of oral squamous cell carcinoma (OSCC) treated by surgery and adjuvant radiotherapy at the time of secondary corrective surgery. Topic-defined PIQOR (Parallel Identification and Quantification of RNAs) skin microarrays were used to compare gene expression profiles between control and irradiated skin sample in 8 patients. The data were validated for matrixmetalloproteinase (MMP)-1 and tissue-inhibitor of matrixmetalloproteinase (TIMP)-1 by RT-PCR for all patients. RESULTS: Irradiation markedly enhanced the expression of molecules associated with the transforming growth factor (TGF)-beta(1) signaling pathway, blood vessel development, as well as extracellular matrix constitution and turn-over. CONCLUSIONS: Our data suggest that radiation-induced late changes in cutaneous gene expression mainly affect molecules related to extracellular matrix (ECM)-constitution and-remodeling.

Effects of preoperative pelvic irradiation on colonic anastomosis healing. An experimental study in rats.

PURPOSE: Colorectal anastomosis is a constant worry-issue among surgeons because of high rates of complications, specially the dehiscence. The preoperative irradiation on cancer surgeries might interfere in the healing process, leading to an unfavorable outcome. METHODS: In the present study, two groups of rats were irradiated previously to a colorectal anastomosis surgery, with intervals of 4 and 8 weeks between the procedures. Seven days after the surgery, healing process was evaluated for dehiscence presence and histologic inflammatory characteristics. Also, levels of hydroxyproline, metalloproteinases and vascular endothelial growth factor were measured. RESULTS: Our results showed a higher incidence of dehiscences on the animals submitted to irradiation, compared to controls, with a reduced inflammatory activity in the healing tissue. DISCUSSION: Comparing both irradiated groups, those irradiated 8 weeks before surgery showed higher levels of hydroxyproline and metalloproteinases, indicating higher efficiency of the healing process. In conclusion, preoperative irradiation interferes with intestinal anastomosis healing and a larger time interval between both procedures is safer in terms of the healing quality.

Effects of preoperative pelvic irradiation on colonic anastomosis healing: an experimental study in rats / Efeito da radioterapia pélvica pré-operatória na cicatrização de anastomoses colônicas: estudo experimental em ratos

PURPOSE: Colorectal anastomosis is a constant worry-issue among surgeons because of high rates of complications, specially the dehiscence. The preoperative irradiation on cancer surgeries might interfere in the healing process, leading to an unfavorable outcome. METHODS: In the present study, two groups of rats were irradiated previously to a colorectal anastomosis surgery, with intervals of 4 and 8 weeks between the procedures. Seven days after the surgery, healing process was evaluated for dehiscence presence and histologic inflammatory characteristics. Also, levels of hydroxyproline, metalloproteinases and vascular endothelial growth factor were measured. RESULTS: Our results showed a higher incidence of dehiscences on the animals submitted to irradiation, compared to controls, with a reduced inflammatory activity in the healing tissue. DISCUSSION: Comparing both irradiated groups, those irradiated 8 weeks before surgery showed higher levels of hydroxyproline and metalloproteinases, indicating higher efficiency of the healing process. In conclusion, preoperative irradiation interferes with intestinal anastomosis healing and a larger time interval between both procedures is safer in terms of the healing quality.

INTRODUÇÃO: As anastomoses colorretais são motivos constante de preocupação por parte dos cirurgiões, em virtude do alto índice de complicações, principalmente as deiscências. O uso da radioterapia previamente à cirurgia, nos casos de doença neoplásica, pode interferir no processo cicatricial das anastomoses, e levar a uma evolução desfavorável. MÉTODOS: Os autores estudaram dois grupos de ratos, submetidos a radioterapia e à confecção de uma anastomose no cólon, com intervalo de 04 e de 08 semanas entre os dois procedimentos, comparando com um grupo controle. Após 07 dias da cirurgia, estudaram-se vários aspectos do processo cicatricial: presença de deiscência, características inflamatórias do tecido, dosagem de hidroxiprolina, de mateloproteinase e de VEGF. RESULTADOS: Os autores detectaram maior índice de deiscência nos animais submetidos à radioterapia, com prejuízo da atividade inflamatória característica de um tecido em cicatrização. DISCUSSÃO: Dentre os dois grupos irradiados, aquele com intervalo de oito semanas entre a radioterapia e a confecção da anastomose teve dosagem mais alta de hidroxiprolina e metaloproteinase, demonstrando maior eficiência do processo cicatricial. CONCLUSÃO: A radioterapia prévia interfere no processo de cicatrização das anastomoses intestinais, e que um maior intervalo de tempo entre os dois procedimentos é melhor para garantia de uma cicatrização satisfatória.

Effects of two conventional preoperative radiation schedules on anastomotic healing in the rat colon.

BACKGROUND: Preoperative radiotherapy (RT) is an increasingly popular form of adjunct therapy for rectal cancer; however, little is known about its effects on matrix metalloproteinase (MMP) expression in colonic anastomotic healing. METHODS: Wistar rats were irradiated to a total dose of 25 or 40 Gy. Four days after the end of RT, an end-to-end colorectal anastomosis was performed. Animals were sacrificed at 1, 3, and 7 days after the anastomosis. A control group was studied similarly, but was not irradiated. RESULTS: No significant differences were found in peritonitis rate and anastomotic complications. The average bursting pressure and breaking strength were only reduced significantly in the rats irradiated with 40 Gy. However, the concentration and the content of hydroxyproline in anastomotic tissues were unchanged. In irradiated rats, MMP-2 and MMP-9 were significantly increased at 40 Gy, but not at 25 Gy. On the other hand, 25-Gy irradiation induced a smaller increase in the levels of the tissue inhibitors of metalloproteinase-1 compared with the controls. CONCLUSION: Anastomotic strength is adversely affected by high-dose fractionated preoperative RT. In contrast, preoperative RT at 25 Gy in five fractions over 5 days is safe with regard to the maintenance of wound strength in colorectal anastomosis.

Stress-related modulation of matrix metalloproteinase expression.

Matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs), whose expression can be controlled by cytokines, play a role in extracellular matrix remodeling in physiological and pathological processes. Using a blister chamber wound model on UV-B-exposed human forearm skin, we examined whether stress or mood-associated neuroendocrine alteration is sufficient to modulate MMP and TIMP expression. We did not find evidence that depressive symptoms were reliably associated with modulation of either MMP or TIMP expression. However, we did find that activation of the hypothalamic-pituitary-adrenal (HPA) and sympathetic-adrenal medullary (SAM) axes can modulate levels of MMPs. A positive association between plasma norepinephrine levels and MMP-2 protein levels, and a negative correlation between plasma cortisol levels and MMP-2 levels were found. The data suggest that activation of the HPA and SAM axes, even in individuals within the normal range of depressive symptoms, could mediate MMP levels and wound healing in blister wounds.