No description available.

O objetivo do estudo foi investigar o remodelamento tecidual e fatores modulados pela via do TGFβ no tecido adiposo subcutâneo na vigência da caquexia associada ao câncer gastrointestinal. O estudo incluiu 59 pacientes divididos em três grupos: Controle, Câncer de peso estável (WSC) e Câncer e Caquexia (CC). Foram observadas alterações morfológicas exclusivas ao tecido adiposo do grupo CC. Houve o aumento na deposição de colágeno, glicoproteínas associadas, e fibras do sistema elásticas. A imunohistoquímica revelou alterações no conteúdo dos colágenos do tipo I, III e VI, e da fibronectina no grupo CC em relação ao grupo Controle e WSC. A presença de miofibroblastos no grupo CC foi confirmada pela imunomarcação para αSMA, e o aumento de 20 vezes do gene FSP1 no tecido adiposo, em associação com expressiva marcação de vimentina em fibroblastos isolados. As concentrações do TGFβ3 estavam aumentadas no tecido adiposo, e TGFβ1 e TGFβ3 nos adipócitos, dos pacientes caquéticos. A imunolocalização revelou maior intensidade para SMAD3 e SMAD4 no grupo CC. Em conclusão, na caquexia associada ao câncer, a via do TGFβ contribui para o comprometimento da biologia do tecido adiposo e o desenvolvimento da fibrose. / Aim of the study was to investigate tissue remodelling and factors modulated by TGFβ pathway in the subcutaneous adipose tissue in gastrointestinal cancer cachexia. The study included 59 patients enrolled into three groups: Control, Weight-stable Cancer (WSC) and Cancer Cachexia (CC). Morphological alterations (HE) were observed in adipose tissue from CC group solely, with reduction in the content of fat cells (area, diameter and circumference). Markedly stain to collagens type I, III, IV and fibronectin by immunohistochemistry revealed changes in the CC group as compared to the control and WSC group. Presence of myofibroblasts in CC group was observed by immunostaining for αSMA, and 20-fold increase of the FSP1 gene in adipose tissue. In association, was reported higher expression for vimentin in isolated fibroblasts. TGFβ3 concentrations were enhanced in adipose tissue, and TGFβ1 and TGFβ3 in adipocytes of cachectic patients in relation to control group. Immunolocalization revealed greater intensity for SMAD3 and SMAD4 in the CC group. Thus, during cancer cachexia the TGFβ pathway contributes to disruption of adipose tissue biology and fibrosis development.

A inflamação sistêmica é uma das características que marcam o diagnóstico da caquexia associada ao câncer. Entre as interações tumor-hospedeiro, o tecido adiposo branco contribui à inflamação, uma vez que ele sofre uma reorganização morfológica e lipólise, liberando ácidos graxos livres (AGLs), mediadores lipídicos (LMs) e citocinas pró-inflamatórias, que acentuam a ativação de vias de sinalização pró-inflamatória e o recrutamento de células do sistema imunológico para o tecido. O objetivo deste projeto foi investigar quais fatores inflamatórios sistêmicos estão envolvidos na inflamação do tecido adiposo e qual é a influência desses fatores sobre as enzimas envolvidas no metabolismo dos AGs ou LMs em indivíduos saudáveis (Controle), pacientes com câncer gastrointestinal com peso estável (WSC) e pacientes com câncer e caquexia (CC). Os resultados demonstraram que a resposta inflamatória sistêmica é diferente da resposta encontrada no tecido adiposo. A inflamação sistêmica dos pacientes com câncer e caquexia (CC) foi caracterizada por níveis circulantes mais elevados de ácidos graxos saturados (SFAs), tumor-necrosis-factor-&#945 (TNF-&#945), Interleukin IL-6, IL-8 e proteina Creativa (PCR), enquanto os níveis de ácidos graxos poliinsaturados (PUFAs), especialmente n3-PUFAs, foram menores em CC que nos demais grupos. In vitro e em explantes de tecido adiposo, citocinas pró-inflamatórias e SFAs aumentaram a expressão das quimiocinas IL-8 e CXCL10. E também observamos um aumento na expressão destas quimiocinas na inflamação do tecido adiposo no CC, que era mais profundo no tecido adiposo visceral (VAT) quando comparado ao tecido adiposo subcutâneo (SAT). A inflamação sistêmica foi negativamente associada com a expressão de enzimas sintetizadoras dos PUFAs, embora a expressão gênica e protéica mostraram somente pequenas diferencias entre os grupos. Os efeitos dos fatores inflamatórios sobre as enzimas no tecido adiposo podem ter sido mascarados pela modulação diferenciada dos diversos tipos celulares constituintes desse tecido. Experimentos in vitro mostraram que a expressão de enzimas que modificam os AGs, tais como as dessaturases e elongases em adipócitos e macrófagos, foram reguladas em direções opostas por TNF-&#945, IL-6, LPS e palmitato. Mesmo os pacientes CC demonstrando uma maior concentração plasmática da Resolvina D1, que é um mediador lipídico de resolução da inflamação, ainda assim, a inflamação sistêmica é maior nesses pacientes, e os resultados indicam que as citoquinas inflamatórias interferem com as vias de síntese das LMs da resolução. Concluímos que, os dados revelaram um crosstalk inter-tecidual e intercelular complexo mediado por citocinas pró-inflamatórias e compostos lipídicos que aumentam a inflamação na caquexia associada ao câncer por mecanismos autoregulação. / Systemic inflammation is a hallmark of cancer cachexia. Among tumor-host interactions, the white adipose tissue (WAT) is an important contributor to inflammation as it suffers morphological reorganization and lipolysis, releasing free fatty acids (FA), bioactive lipid mediators (LM) and pro-inflammatory cytokines, which accentuate the activation of proinflammatory signaling pathways and the recruitment of immune cells to the tissue. This project aimed to investigate which inflammatory factors are involved in the local adipose tissue inflammation and what is the influence of such factors upon enzymes involved in FA or LM metabolism in healthy individuals (Control), weight stable gastro-intestinal cancer patients (WSC) and cachectic cancer patients (CC). The results demonstrated that the inflammatory signature of systemic inflammation is different from local adipose tissue inflammation. The systemic inflammation of the cachectic cancer patients was characterized by higher levels of circulating saturated fatty acids (SFA), tumor-necrosisfactor- &#945 (TNF- &#945), interleukins IL-6, IL-8 and CRP while levels of polyunsaturated fatty acids (PUFAs), especially n3-PUFAs, were lower in CC than in the other groups. In vitro and in adipose tissue explants, pro-inflammatory cytokines and SFAs were shown to increase the chemokines IL-8 and CXCL10 that were found to be augmented in adipose tissue inflammation in CC which was more profound in the visceral adipose tissue (VAT) than in subcutaneous adipose tissue (SAT). Systemic inflammation was negatively associated with the expression of PUFA synthesizing enzymes, though gene and protein expression did hardly differ between groups. The effects of inflammatory factors on enzymes in the whole tissue could have been masked by differentiated modulation of the diverse cell types in the same tissue. In vitro experiments showed that the expression of FA-modifying enzymes such as desaturases and elongases in adipocytes and macrophages was regulated into opposing directions by TNF- &#945, IL-6, LPS or palmitate. The higher plasma concentration of the pro-resolving LM resolvin D1 in CC cannot compensate the overall inflammatory status and the results indicate that inflammatory cytokines interfere with synthesis pathways of pro-resolving LM. In summary, the data revealed a complex inter-tissue and inter-cellular crosstalk mediated by pro-inflammatory cytokines and lipid compounds enhancing inflammation in cancer cachexia by feedforward mechanisms.

Doctor of Philosophy / Introduction Cachexia is characterised by a marked weight loss and the presence of anorexia, anaemia, and asthenia. Although cachexia is often associated with the presence and growth of tumour and observed in solid tumours of the upper gastrointestinal tract, its presence is not unique to cancer and is often also present in most chronic, end-stage diseases processes. The loss of body fat, altered lipid metabolism, increase in the resting energy expenditure, and the increased loss of body protein the degree of which is associated with poor survival, are all hallmarks of this detrimental disease. The clinical aspects and consequences of cachexia can simply be summarised as morbidity, debilitating conditions, and mortality. The conditions such as loss of muscle mass, impaired muscle function, fatigue, reduced activity and functional capacity by themselves are enough to severely and significantly affect the patients’ QL. Although different interventional procedures and therapies are available for the treatment of cachexia and its symptoms, effective methods to evaluate their benefits and outcomes have not been tested or investigated. It was, therefore, the aim of this project to use body composition analysis as a clinical tool and evaluate the effectiveness and outcome of interventional and therapeutic procedures in three groups of patients with cancer. Methods Three patient groups were investigated: 1) patients with pancreatic cancer undergoing Whipple’s Procedure, 2) patients with pancreatic cancer undergoing cancer chemotherapy and receiving either EPA or placebo, and 3) patients with malignant mesothelioma undergoing cancer chemotherapy plus thalidomide or thalidomide alone. Body composition analysis techniques were used to assess the changes in TBN, TBF, TBK, and TBW. In addition, the body composition parameters together with clinical measures were also used to determine parameters influencing survival. The malignant mesothelioma patients were randomised into patients who received gemcitabine / cisplatin plus thalidomide and those who received thalidomide alone. The pancreatic cancer patients undergoing chemotherapy were randomised into the group who were receiving EPA and those who were receiving placebo. In addition, these patients were also investigated on the basis of their disease extent where they were separated into two groups of metastatic and locally advanced. Unpaired T-Test and ANOVA were used to determine differences between groups. Kaplan-Meier analysis and Cox’s Regression were used to assess survival in all three patient cohorts. The Whipple’s Procedure patients were separated into those who received a Clear Margin and those who received an Unclear Margin during their resection. Results 1) In the pancreatic cancer patients undergoing Whipple’s Procedure, compared to the base-line, there were highly significant changes in Weight (p=0.006), BMI (p=0.005), and FM (p=0.007) followed by significant changes in %BFat (p=0.016), TBK/Ht (p=0.021), LBM (By TBK) (p=0.023), LBM (Van Loan) (p=0.034), and LBM (Segal) (p=0.038) at the 14 week time-point. At the 26 weeks post-operative time point, the only significant changes were in the FM (p=0.012), %BFat (p=0.003), and BMI (p=0.027) parameters. There was also a deviation between the two groups in their TBN, LBM and TBW content observable in a long-term setting and fat content in the relatively shorter-term. Although the Unclear Margin group had lower body composition values, both groups seem to begin to gradually “equalise” around the 14 weeks post-operative time-point. The survival analysis results for the Whipple’s Procedure patients demonstrated that Margin Status (p=0.001), Fat Mass (p=0.003) and Age (p=0.081) were significant and could influence survival. 2) When the second cohort pancreatic cancer patients undergoing chemotherapy were analysed, they were initially separated according to the extent of their disease The results of the analyses of body composition changes between measurement time-points for the each group separately, suggested that the patients with locally advanced disease maintain their Weight, FM, and TBN but are more likely to have a lower TBW by the end of the four month of chemotherapy. However, the patients with metastatic pancreatic cancer maintain their TBW but are more likely to have a decreased fat compartment and a higher FFM. The QL analysis showed that the metastatic group are performing “worse” than the locally advanced group especially in term of their Dyspnoea, Nausea & Vomiting, and Sexuality. In addition, the Karnofsky score showed that the metastatic group are not performing as well as the locally advanced group. Furthermore, for the metastatic group there was an increase in the patients’ pain with a decline in mood and general performance as well as increase in gastrointestinal symptoms. Pain Card scores also showed a general increase for the metastatic group and a general decrease for the locally advanced group. When the pancreatic cancer patients undergoing chemotherapy were separated according to whether they received EPA or placebo, the results demonstrated that firstly, due to the fact that the patients were well randomised, the two groups commenced the trial with similar and statistically non-significantly different body composition parameters. Secondly, the two groups were also found to be statistically not different at their corresponding measurement time-points. And thirdly, the patients receiving placebo compared to those receiving EPA lost more Weight, and FM but less TBW throughout the trial. The TBK/Ht (p=0.044), TBK (p=0.042), and LBM (By TBK) (p=0.042), however, showed statistically significant differences where in all three parameters the EPA showed an increase compared to the base-line (pre-chemotherapy). Results of the survival analysis demonstrated that the use of EPA in this group of pancreatic cancer patients did not provide any benefit. In fact, as it was shown in the Kaplan-Meier plot, the group of patients receiving the EPA had a “worse” survival than the group receiving the placebo. The QL results showed that placebo group improved in their functional scales, but increased their Altered Bowel Habit scores with an increase in the perception of pain and decrease in relief from pain. The EPA group, however, showed a decrease in the Loss of Appetite, Dyspnoea, Pain, Pancreatic Pain, and Fatigue, and improvements in Role Functioning and Sexuality. 3) Results of the malignant mesothelioma patients demonstrated that both study arms show similar weight changes. In addition, body composition measurements indicated that the gemcitabine / cisplatin chemotherapy plus thalidomide group had a greater TBN loss and a greater TBW gain than the thalidomide-alone group. This loss of TBN and gain in TBW looked to be “concealed” in the weight. The results of the survival analysis carried out on the mesothelioma patient group suggested that haemoglobin levels (p=0.001), Age (p=0.007), and NI (p=0.008) are the parameters that can influence the survival of patients with malignant mesothelioma undergoing chemotherapy. Conclusions 1) The trend in body composition changes in the Whipple’s Procedure group showed that, although both groups may start with non-significantly different body composition, they tended to grow closer around the 14 week point indicating that the Clear Margin group may lose more than Unclear Margin group. The implications of these findings, therefore, were that once the most appropriate surgical procedure is performed, an adjuvant therapy regimen (such as chemotherapy) at around 14 weeks may have the most impact on the patient’s overall treatment outcome. 2) When the pancreatic cancer patients were separated by the extent of their disease, the results lead to the conclusion that the patients with locally advanced disease maintain their Weight, FM, and TBN but are more likely to have a lower TBW by the end of the four month of chemotherapy. However, the patients with metastatic pancreatic cancer maintain their TBW but are more likely to have a decreased fat compartment and a higher FFM. The QL analysis concluded that the results may point to a worsening and/or progressing disease which is consistent with classic metastatic disease aetiology. From the results of the pancreatic cancer patients undergoing cancer chemotherapy it was concluded that the use of EPA in this group of pancreatic cancer patients undergoing cancer chemotherapy with gemcitabine results in a non-significant reduction in weight loss, FM loss, and TBW gain with a statistically significant increase in FFM. The results of the survival analysis was, however, contradictory suggesting that patients receiving EPA may have a worse survival than the placebo group. The QL analysis here concluded that that EPA does improve the QL of this group of pancreatic cancer patients. 3) From the malignant mesothelioma group it was concluded that provided that the overall anti-cancer potential of gemcitabine / cisplatin plus thalidomide is comparable with that of thalidomide-alone, then by looking purely from the body composition angle one may be able to suggest the use of thalidomide alone in the treatment of malignant mesothelioma in this group of patients. From the results of the survival analysis, the fact that the Study Arm parameter did not reach statistical significance could indicate that survival in these patients is not affected by the presence or absence of chemotherapy with gemcitabine and cisplatin. The body composition techniques were used here as a tool to monitor changes in various body composition parameters to assess the outcomes, including survival, of the administration of different therapies and interventional procedures in these three groups of cancer patients. For these purposes, these techniques were demonstrated to be an effective and invaluable tool.

No description available.

The purpose of this work was to further understand nutritional status, especially body weight and composition, during colorectal cancer progression. Population-based studies of colorectal cancer patients were conducted using administrative health data (primary and co-morbid diseases, demographics), and computed tomography (CT) imaging (body composition). In cohort 1, administrative health data was used to study comorbidities and nutritional status in 574 colorectal cancer patients referred for chemotherapy. Multivariate Cox regression revealed several comorbidities, performance status and weight loss 20% predicted survival. In cohort 2, a serial CT image analysis assessed longitudinal body composition changes during the last 12 months preceding death from colorectal cancer (n=34). Body composition changes were typified by exponential increases in liver metastases with concurrent accelerations of muscle and fat loss. These results have the potential to make a difference in how colorectal cancer patients are treated and researched by dietitians, oncologists, and health services researchers. / Nutrition and Metabolism

Doctor of Philosophy / Introduction Cachexia is characterised by a marked weight loss and the presence of anorexia, anaemia, and asthenia. Although cachexia is often associated with the presence and growth of tumour and observed in solid tumours of the upper gastrointestinal tract, its presence is not unique to cancer and is often also present in most chronic, end-stage diseases processes. The loss of body fat, altered lipid metabolism, increase in the resting energy expenditure, and the increased loss of body protein the degree of which is associated with poor survival, are all hallmarks of this detrimental disease. The clinical aspects and consequences of cachexia can simply be summarised as morbidity, debilitating conditions, and mortality. The conditions such as loss of muscle mass, impaired muscle function, fatigue, reduced activity and functional capacity by themselves are enough to severely and significantly affect the patients’ QL. Although different interventional procedures and therapies are available for the treatment of cachexia and its symptoms, effective methods to evaluate their benefits and outcomes have not been tested or investigated. It was, therefore, the aim of this project to use body composition analysis as a clinical tool and evaluate the effectiveness and outcome of interventional and therapeutic procedures in three groups of patients with cancer. Methods Three patient groups were investigated: 1) patients with pancreatic cancer undergoing Whipple’s Procedure, 2) patients with pancreatic cancer undergoing cancer chemotherapy and receiving either EPA or placebo, and 3) patients with malignant mesothelioma undergoing cancer chemotherapy plus thalidomide or thalidomide alone. Body composition analysis techniques were used to assess the changes in TBN, TBF, TBK, and TBW. In addition, the body composition parameters together with clinical measures were also used to determine parameters influencing survival. The malignant mesothelioma patients were randomised into patients who received gemcitabine / cisplatin plus thalidomide and those who received thalidomide alone. The pancreatic cancer patients undergoing chemotherapy were randomised into the group who were receiving EPA and those who were receiving placebo. In addition, these patients were also investigated on the basis of their disease extent where they were separated into two groups of metastatic and locally advanced. Unpaired T-Test and ANOVA were used to determine differences between groups. Kaplan-Meier analysis and Cox’s Regression were used to assess survival in all three patient cohorts. The Whipple’s Procedure patients were separated into those who received a Clear Margin and those who received an Unclear Margin during their resection. Results 1) In the pancreatic cancer patients undergoing Whipple’s Procedure, compared to the base-line, there were highly significant changes in Weight (p=0.006), BMI (p=0.005), and FM (p=0.007) followed by significant changes in %BFat (p=0.016), TBK/Ht (p=0.021), LBM (By TBK) (p=0.023), LBM (Van Loan) (p=0.034), and LBM (Segal) (p=0.038) at the 14 week time-point. At the 26 weeks post-operative time point, the only significant changes were in the FM (p=0.012), %BFat (p=0.003), and BMI (p=0.027) parameters. There was also a deviation between the two groups in their TBN, LBM and TBW content observable in a long-term setting and fat content in the relatively shorter-term. Although the Unclear Margin group had lower body composition values, both groups seem to begin to gradually “equalise” around the 14 weeks post-operative time-point. The survival analysis results for the Whipple’s Procedure patients demonstrated that Margin Status (p=0.001), Fat Mass (p=0.003) and Age (p=0.081) were significant and could influence survival. 2) When the second cohort pancreatic cancer patients undergoing chemotherapy were analysed, they were initially separated according to the extent of their disease The results of the analyses of body composition changes between measurement time-points for the each group separately, suggested that the patients with locally advanced disease maintain their Weight, FM, and TBN but are more likely to have a lower TBW by the end of the four month of chemotherapy. However, the patients with metastatic pancreatic cancer maintain their TBW but are more likely to have a decreased fat compartment and a higher FFM. The QL analysis showed that the metastatic group are performing “worse” than the locally advanced group especially in term of their Dyspnoea, Nausea & Vomiting, and Sexuality. In addition, the Karnofsky score showed that the metastatic group are not performing as well as the locally advanced group. Furthermore, for the metastatic group there was an increase in the patients’ pain with a decline in mood and general performance as well as increase in gastrointestinal symptoms. Pain Card scores also showed a general increase for the metastatic group and a general decrease for the locally advanced group. When the pancreatic cancer patients undergoing chemotherapy were separated according to whether they received EPA or placebo, the results demonstrated that firstly, due to the fact that the patients were well randomised, the two groups commenced the trial with similar and statistically non-significantly different body composition parameters. Secondly, the two groups were also found to be statistically not different at their corresponding measurement time-points. And thirdly, the patients receiving placebo compared to those receiving EPA lost more Weight, and FM but less TBW throughout the trial. The TBK/Ht (p=0.044), TBK (p=0.042), and LBM (By TBK) (p=0.042), however, showed statistically significant differences where in all three parameters the EPA showed an increase compared to the base-line (pre-chemotherapy). Results of the survival analysis demonstrated that the use of EPA in this group of pancreatic cancer patients did not provide any benefit. In fact, as it was shown in the Kaplan-Meier plot, the group of patients receiving the EPA had a “worse” survival than the group receiving the placebo. The QL results showed that placebo group improved in their functional scales, but increased their Altered Bowel Habit scores with an increase in the perception of pain and decrease in relief from pain. The EPA group, however, showed a decrease in the Loss of Appetite, Dyspnoea, Pain, Pancreatic Pain, and Fatigue, and improvements in Role Functioning and Sexuality. 3) Results of the malignant mesothelioma patients demonstrated that both study arms show similar weight changes. In addition, body composition measurements indicated that the gemcitabine / cisplatin chemotherapy plus thalidomide group had a greater TBN loss and a greater TBW gain than the thalidomide-alone group. This loss of TBN and gain in TBW looked to be “concealed” in the weight. The results of the survival analysis carried out on the mesothelioma patient group suggested that haemoglobin levels (p=0.001), Age (p=0.007), and NI (p=0.008) are the parameters that can influence the survival of patients with malignant mesothelioma undergoing chemotherapy. Conclusions 1) The trend in body composition changes in the Whipple’s Procedure group showed that, although both groups may start with non-significantly different body composition, they tended to grow closer around the 14 week point indicating that the Clear Margin group may lose more than Unclear Margin group. The implications of these findings, therefore, were that once the most appropriate surgical procedure is performed, an adjuvant therapy regimen (such as chemotherapy) at around 14 weeks may have the most impact on the patient’s overall treatment outcome. 2) When the pancreatic cancer patients were separated by the extent of their disease, the results lead to the conclusion that the patients with locally advanced disease maintain their Weight, FM, and TBN but are more likely to have a lower TBW by the end of the four month of chemotherapy. However, the patients with metastatic pancreatic cancer maintain their TBW but are more likely to have a decreased fat compartment and a higher FFM. The QL analysis concluded that the results may point to a worsening and/or progressing disease which is consistent with classic metastatic disease aetiology. From the results of the pancreatic cancer patients undergoing cancer chemotherapy it was concluded that the use of EPA in this group of pancreatic cancer patients undergoing cancer chemotherapy with gemcitabine results in a non-significant reduction in weight loss, FM loss, and TBW gain with a statistically significant increase in FFM. The results of the survival analysis was, however, contradictory suggesting that patients receiving EPA may have a worse survival than the placebo group. The QL analysis here concluded that that EPA does improve the QL of this group of pancreatic cancer patients. 3) From the malignant mesothelioma group it was concluded that provided that the overall anti-cancer potential of gemcitabine / cisplatin plus thalidomide is comparable with that of thalidomide-alone, then by looking purely from the body composition angle one may be able to suggest the use of thalidomide alone in the treatment of malignant mesothelioma in this group of patients. From the results of the survival analysis, the fact that the Study Arm parameter did not reach statistical significance could indicate that survival in these patients is not affected by the presence or absence of chemotherapy with gemcitabine and cisplatin. The body composition techniques were used here as a tool to monitor changes in various body composition parameters to assess the outcomes, including survival, of the administration of different therapies and interventional procedures in these three groups of cancer patients. For these purposes, these techniques were demonstrated to be an effective and invaluable tool.

O objetivo do estudo foi investigar o remodelamento tecidual e fatores modulados pela via do TGFβ no tecido adiposo subcutâneo na vigência da caquexia associada ao câncer gastrointestinal. O estudo incluiu 59 pacientes divididos em três grupos: Controle, Câncer de peso estável (WSC) e Câncer e Caquexia (CC). Foram observadas alterações morfológicas exclusivas ao tecido adiposo do grupo CC. Houve o aumento na deposição de colágeno, glicoproteínas associadas, e fibras do sistema elásticas. A imunohistoquímica revelou alterações no conteúdo dos colágenos do tipo I, III e VI, e da fibronectina no grupo CC em relação ao grupo Controle e WSC. A presença de miofibroblastos no grupo CC foi confirmada pela imunomarcação para αSMA, e o aumento de 20 vezes do gene FSP1 no tecido adiposo, em associação com expressiva marcação de vimentina em fibroblastos isolados. As concentrações do TGFβ3 estavam aumentadas no tecido adiposo, e TGFβ1 e TGFβ3 nos adipócitos, dos pacientes caquéticos. A imunolocalização revelou maior intensidade para SMAD3 e SMAD4 no grupo CC. Em conclusão, na caquexia associada ao câncer, a via do TGFβ contribui para o comprometimento da biologia do tecido adiposo e o desenvolvimento da fibrose. / Aim of the study was to investigate tissue remodelling and factors modulated by TGFβ pathway in the subcutaneous adipose tissue in gastrointestinal cancer cachexia. The study included 59 patients enrolled into three groups: Control, Weight-stable Cancer (WSC) and Cancer Cachexia (CC). Morphological alterations (HE) were observed in adipose tissue from CC group solely, with reduction in the content of fat cells (area, diameter and circumference). Markedly stain to collagens type I, III, IV and fibronectin by immunohistochemistry revealed changes in the CC group as compared to the control and WSC group. Presence of myofibroblasts in CC group was observed by immunostaining for αSMA, and 20-fold increase of the FSP1 gene in adipose tissue. In association, was reported higher expression for vimentin in isolated fibroblasts. TGFβ3 concentrations were enhanced in adipose tissue, and TGFβ1 and TGFβ3 in adipocytes of cachectic patients in relation to control group. Immunolocalization revealed greater intensity for SMAD3 and SMAD4 in the CC group. Thus, during cancer cachexia the TGFβ pathway contributes to disruption of adipose tissue biology and fibrosis development.

La cachexie est un syndrome clinique et métabolique caractérisé par une perte de tissu adipeux et de tissu musculaire, fréquemment observé chez les patients atteints de cancer. La myostatine (Mstn) régule négativement la masse musculaire. Bien que la régulation des mécanismes moléculaires impliqués dans le contrôle de la masse musculaire joue un rôle central dans la cachexie associée au cancer, les relations existant entre la Mstn et les mécanismes physiopathologiques restent largement inconnues. Suite à l’inoculation de cellules Lewis lung carcinoma (LLC) à des souris, nous avons montré que l’invalidation du gène de la Mstn (souris Mstn-/-) confère une résistance au développement de la cachexie associée au cancer par rapport à des souris sauvages. La déficience en Mstn prévient la perte de masse musculaire et réduit la croissance tumorale, 35 jours après l’injection des cellules LLC, et est associée à un allongement de la durée de vie des souris. L’invalidation du gène de la Mstn provoque aussi une augmentation de l’apoptose des cellules LLC et une diminution de l'expression de gènes impliqués dans la prolifération et le métabolisme tumoraux. L’activation des systèmes protéolytiques ubiquitine-protéasome et autophagie-lysosome, due au développement tumoral, est réduite voire supprimée dans le muscle des souris Mstn-/-. L’accumulation de céramides intramusculaires, un sphingolipide formé suite à une lipolyse exacerbée, est corrélée à la perte de masse musculaire, suggérant que les céramides pourraient être un médiateur cellulaire impliqué dans la cachexie associée au cancer. Ces résultats montrent que la Mstn joue un rôle essentiel dans la cachexie associée au cancer / Cachexia is a complex clinical and metabolic syndrome, whose definition is imprecise, characterized by an uncontrolled loss of adipose tissue and skeletal muscle mass, frequently observed in cancer patients, and leading to death in 25% of cancer patients. Myostatin (Mstn) is a negative regulator of skeletal muscle mass and a critical determinant of skeletal muscle homeostasis. Although the regulation of the molecular mechanisms involved in the control of skeletal muscle mass plays a central role in the pathogenesis of cancer cachexia, the relationships between Mstn and the pathophysiological mechanisms remain largely unknown. Following subcutaneous inoculation of Lewis lung carcinoma cells (LLC) in mice, we showed that the Mstn gene inactivation (Mstn-/- mice) confers resistance to the development of cancer cachexia, compared to wild type mice. Mstn deficiency prevents the loss of skeletal muscle mass and reduces tumor growth, 35 days after the inoculation of LLC cells, and this is associated with a longer life of mice. Mstn gene inactivation also causes an increased apoptosis of LLC cells and decreases expression of genes involved in tumor proliferation and metabolism. Activation of ubiquitin-proteasome and autophagy-lysosome proteolytic systems, triggered by tumor growth is significantly reduced or suppressed in skeletal muscle of Mstn-/- mice. Accumulation of intramuscular ceramides, a sphingolipid synthesized due to excessive lipolysis, is correlated with the loss of muscle mass, suggesting that ceramides may be a cellular mediator involved in the pathogenesis of cancer cachexia. These results show that Mstn plays a critical role in the pathogenesis of cancer cachexia

No description available.