In-vitro model to mimic T cell subset change in human PDAC organoid co-culture.

PURPOSE: Immunotherapies have largely failed as treatment options for pancreatic ductal adenocarcinoma (PDAC). In this field, clinical translational studies into personalized treatment are of fundamental importance. In our study, we model tumor-cell immune-cell interactions in a co-culture of primary human PDAC organoids and matched peripheral blood mononuclear cells (PBMCs). METHODS: Using flow cytometry, we evaluated changes in T cell subtypes upon co-culture of patient-derived PDAC organoids and matched PBMCs. RESULTS: After co-culturing PDAC organoids with PBMCs, we observed changes in CD4+, CD8+ and Treg cell populations. We observed favorable clinical outcome in patients whose PBMCs reacted to the co-culture with organoids. CONCLUSION: This experimental model allows to investigate interactions between patient derived PDAC organoids and their PBMCs. This co-culture system could serve as a preclinical platform to guide personalized therapeutic strategies in the future.

Preservation of the round ligament to accommodate transient portal hypertension after major hepatectomy.

PURPOSE: Posthepatectomy liver failure (PHLF) remains a leading cause of death after extensive liver resection. Apart from the size and function of the remaining liver remnant, the development of postresection portal hypertension (pHT) plays a crucial role in the development of PHLF. We hypothesize that the umbilical vein in the preserved round ligament (RL) may recanalize in response to new-onset pHT after extended hepatectomy, thus providing a natural portosystemic shunt. METHODS: In this exploratory study, RL was preserved in 10 consecutive patients undergoing major liver resection. Postoperative imaging was pursued to obtain evidence of reopened umbilical vein in the RL. The postoperative course, including the occurrence of PHLF, as well as the rate of procedure-specific complications were recorded. RESULTS: None of the 10 cases presented with an adverse event due to preservation of the RL. In 6 cases, postoperative imaging demonstrated reopening of the umbilical vein with hepatofugal flow in the RL. The rates of procedure-related surgical complications were lower than would be expected in this population; in particular, the rate of occurrence of PHLF as defined by the International Study Group of Liver Surgery (ISGLS) was low. CONCLUSION: Our results support the theoretical concept of portosystemic pressure relief via a preserved umbilical vein after major liver surgery. As preservation of the RL is easily done, we suggest keeping it intact in extended hepatectomy cases and in patients with preexistent pHT.

Age and metastasis - How age influences metastatic spread in cancer. Colorectal cancer as a model.

Metastasis is the major cause of death in cancer patients. Whereas colorectal cancer (CRC) incidence increases with age, metastatic spread seems to decline. Furthermore, the epidemiology of CRC is changing. There is an increase in CRC incidence in the young, presenting at an advanced stage with higher likelihood of synchronous or metachronous metastases, and a decline in CRC incidence and metastatic spread in the oldest-old. Emerging data suggest that age-related changes with regard to tumor biology (e.g. genomic instability), the tumor microenvironment (e.g. inflammaging) and the immune system (e.g. immunosenescence), complemented by interaction between the genome and exposome might contribute to the observed metastatic patterns. As aging is a key prognostic factor, this highlights the need for further studies investigating age-related patterns and underlying mechanisms of tumor growth and dissemination. Eventually, this might allow for better risk stratification, refinement of screening strategies and follow-up care as well as therapies tailored to reflect patient age and that might possibly target responsible biomarkers in a precision medicine approach. This review aims to discuss the influence of aging on metastatic spread in colorectal cancer and elucidate underlying mechanisms responsible for the observed metastatic patterns.

Postoperative chyle leak after pancreatic surgery - Is treatment effective?

PURPOSE: With increasing soft tissue clearance in pancreatic cancer surgery, postoperative chyle leak (CL) has become a more commonly observed complication. Recently, a new consensus definition was established by the International study group of pancreatic surgery (ISGPS). The aim of the present analysis was to evaluate risk factors and treatment options of patients with CL after pancreatic surgery. METHODS: Two hundred and twenty-eight patients with serous or chylous drainage after pancreatic surgery were included in this analysis of a prospectively collected database between 01/2014 and 12/2016. Risk factors for CL and treatment options were compared. A subgroup analysis on those patients, who had drain removal despite of persistent CL with respect to the need of subsequent percutaneous drainage or reoperation within three months postoperatively, was performed. RESULTS: Sixty patients with CL were identified. Of those, 41 patients were treated with medium-chain triglyceride-diet, with a median duration of therapy of 12 days. In patients with CL, the type of treatment had no effect on time to drain removal (P=0.29) and morbidity (P=0.15). Furthermore, morbidity was not increased in patients who had their drains removed despite persistent CL (P=0.84). None of the latter patients had percutaneous drainage or reoperation for CL after removal of the surgical drains. CONCLUSIONS: Dietary treatment may not be very effective in treating CL. Further research is warranted to explore the effect and necessity of CL treatment.

LIN28 promotes tumorigenesis in colorectal cancer but is not associated with metastatic spread.

BACKGROUND: Tumor stem cells play a role in metastatic spread in colorectal cancer (CRC). The oncogene LIN28A/B, a prognostic marker in CRC, is involved in tumorigenesis and maintains stem cell function. Therefore, it was the aim of the present study to clarify whether LIN28A/B is involved in metastatic spread in CRC. METHODS: Expression of LIN28A/B was analyzed in patients with colon adenocarcinoma in a matched case-control study comparing patients with corresponding liver metastases (n = 42) and patients without hepatic spread within five years (n = 42) by applying immunohistochemistry. Further, LIN28A/B expression was correlated with stem cell associated markers (SOX2, CD133). RESULTS: LIN28A and B expression significantly correlated with SOX2 expression (p = .02, and p = .04 respectively) but not with CD133 expression. This correlation between LIN28 A/B and SOX2 was not reflected in differences in hepatic spread. In this respect, there was no significant association between LIN28A/B expression and liver metastases. CONCLUSION: LIN28A/B might be involved in tumor initiation and progression in CRC but is not associated with hepatic spread.

Effect of platelet inhibition with perioperative aspirin on survival in patients undergoing curative resection for pancreatic cancer: a propensity score matched analysis.

BACKGROUND: The importance of platelets in the pathogenesis of metastasis formation is increasingly recognized. Although evidence from epidemiologic studies suggests positive effects of aspirin on metastasis formation, there is little clinical data on the perioperative use of this drug in pancreatic cancer patients. METHODS: From all patients who received curative intent surgery for pancreatic cancer between 2014 and 2016 at our institution, we identified 18 patients that took aspirin at time of admission and continued to throughout the inpatient period. Using propensity score matching, we selected a control group of 64 patients without aspirin intake from our database and assessed the effect of aspirin medication on overall, disease-free, and hematogenous metastasis-free survival intervals as endpoints. RESULTS: Aspirin intake proved to be independently associated with improved mean overall survival (OS) (46.5 vs. 24.6 months, *p = 0.006), median disease-free survival (DFS) (26 vs. 10.5 months, *p = 0.001) and mean hematogenous metastasis-free survival (HMFS) (41.9 vs. 16.3 months, *p = 0.005). Three-year survival rates were 61.1% in patients with aspirin intake vs. 26.3% in patients without aspirin intake. Multivariate cox regression showed significant independent association of aspirin with all three survival endpoints with hazard ratios of 0.36 (95% CI 0.15-0.86) for OS (*p = 0.021), 0.32 (95% CI 0.16-0.63) for DFS (**p = 0.001), and 0.36 (95% CI 0.16-0.77) for HMFS (*p = 0.009). CONCLUSIONS: Patients in our retrospective, propensity-score matched study showed significantly better overall survival when taking aspirin while undergoing curative surgery for pancreatic cancer. This was mainly due to a prolonged metastasis-free interval following surgery.

Mechanisms of Metastasis in Colorectal Cancer and Metastatic Organotropism: Hematogenous versus Peritoneal Spread.

Metastasis is the major cause of death in patients with colorectal carcinoma (CRC). The most common sites of metastasis are the liver and the peritoneum. Peritoneal carcinomatosis is often considered the end stage of the disease after the tumor has spread to the liver. However, almost half of CRC patients with peritoneal carcinomatosis do not present with liver metastasis. This brings up the question of whether peritoneal spread can still be considered as the end stage of a metastasized CRC or whether it should just be interpreted as a site of metastasis alternative to the liver. This review tries to discuss this question and summarize the current status of literature on potential characteristics in tumor biology in the primary tumor, i.e., factors (transcription factors and direct and indirect E-cadherin repressors) and pathways (WNT, TGF-ß, and RAS) modulating EMT, regulation of EMT on a posttranscriptional and posttranslational level (miRNAs), and angiogenesis. In addition to tumor-specific characteristics, factors in the tumor microenvironment, immunological markers, ways of transport of tumor cells, and adhesion molecules appear to differ between hematogenous and peritoneal spread. Factors such as integrins and exosomal integrins, cancer stem cell phenotype, and miRNA expression appear to contribute in determining the metastatic route. We went through each step of the metastasis process comparing hematogenous to peritoneal spread. We identified differences with respect to organotropism, epithelial-mesenchymal transition, angiogenesis and inflammation, and tumor microenvironment which will be further elucidated in this review. A better understanding of the underlying mechanisms and contributing factors of metastasis development in CRC has huge relevance as it is the foundation to help find specific targets for treatment of CRC.

Deconstruction of an African folk medicine uncovers a novel molecular strategy for therapeutic potassium channel activation.

A third of the global population relies heavily upon traditional or folk medicines, such as the African shrub Mallotus oppositifolius. Here, we used pharmacological screening and electrophysiological analysis in combination with in silico docking and site-directed mutagenesis to elucidate the effects of M. oppositifolius constituents on KCNQ1, a ubiquitous and influential cardiac and epithelial voltage-gated potassium (Kv) channel. Two components of the M. oppositifolius leaf extract, mallotoxin (MTX) and 3-ethyl-2-hydroxy-2-cyclopenten-1-one (CPT1), augmented KCNQ1 current by negative shifting its voltage dependence of activation. MTX was also highly effective at augmenting currents generated by KCNQ1 in complexes with native partners KCNE1 or SMIT1; conversely, MTX inhibited KCNQ1-KCNE3 channels. MTX and CPT1 activated KCNQ1 by hydrogen bonding to the foot of the voltage sensor, a previously unidentified drug site which we also find to be essential for MTX activation of the related KCNQ2/3 channel. The findings elucidate the molecular mechanistic basis for modulation by a widely used folk medicine of an important human Kv channel and uncover novel molecular approaches for therapeutic modulation of potassium channel activity.

[Oligometastases of neuroendocrine tumors-extent of surgery]. / Oligometastasierung bei neuroendokrinen Tumoren ­ Ausmaß der Chirurgie.

Neuroendocrine tumors (NETs) are rare neoplasms, which represent complex challenges in diagnosis and treatment. Even in the metastatic stage there are important differences in the type of tumor in comparison to gastrointestinal and pancreatic adenocarcinomas. Therefore, the disease courses are substantially different depending on the grade of differentiation. Even in the metastatic stage the 5­year survival rates of G1 tumors is up to 83%. Approximately 20% of small intestine NETs additionally show hormone activity, which can compromise survival and the quality of life. For individual treatment decisions the special tumor biology of these tumors must be taken into consideration more so than for other tumor entities. Surgery always becomes important for these tumors when a R0 resection appears possible. Oligometastasis of the liver and the lymph drainage system can be meaningfully approached by surgical treatment. In selected patients with an isolated liver involvement, a liver transplantation can be considered; however, even tumor debulking can lead to improvement in the quality of life and survival, especially for hormone active tumors with a carcinoid syndrome which cannot be conservatively controlled. The aim of this review is to present the value of surgical treatment options in the case of (oligo)metastasized NETs.

Moon phases and moon signs do not influence morbidity, mortality and long-term survival, after living donor kidney transplantation.

BACKGROUND: Approximately 11% of the German population are convinced that certain moon phases and moon signs may impact their health and the onset and clinical course of diseases. Before elective surgery, a considerable number of patients look to optimize the timing of the procedure based on the lunar cycle. Especially patients awaiting living donor kidney transplantation (LDKT) commonly look for an adjustment of the date of transplantation according to the moon calendar. This study therefore investigated the perioperative and long-term outcome of LDKT dependent on moon phases and zodiac signs. METHODS: Patient data were prospectively collected in a continuously updated kidney transplant database. Two hundred and seventy-eight consecutive patients who underwent LDKT between 1994 and December 2009 were selected for the study and retrospectively assigned to the four moon phases (new-moon, waxing-moon, full-moon, and waning-moon) and the corresponding zodiac sign (moon sign Libra), based on the date of transplantation. Preexisting comorbidities, perioperative mortality, surgical outcome, and long-term survival data were analyzed. RESULTS: Of all LDKT procedures, 11.9, 39.9, 11.5, and 36.5% were performed during the new, waxing, full, and waning moon, respectively, and 6.2% during the moon sign Libra, which is believed to interfere with renal surgery. Survival rates at 1, 5, and 10 years after transplantation were 98.9, 92, and 88.7% (patient survival) and 97.4, 91.6, and 80.6% (graft survival) without any differences between all groups of lunar phases and moon signs. Overall perioperative complications and early graft loss occurred in 21.2 and 1.4%, without statistical difference (p > 0.05) between groups. CONCLUSION: Moon phases and the moon sign Libra had no impact on early and long-term outcome measures following LDKT in our study. Thus, concerns of patients awaiting LDKT regarding the ideal time of surgery can be allayed, and surgery may be scheduled independently of the lunar phases.

Cisplatin and oxaliplatin surface contamination in intensive care units (ICUs) and hospital wards during attendance of HIPEC patients.

PURPOSE: The aim of this pilot study was to evaluate surface contamination by platinum drugs in the environment of patients in ICUs and wards treated by hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: The monitoring included 12 HIPEC treatments from four hospitals during the following 3 days after perfusion. A total of 33 urine and 33 drainage fluids from HIPEC patients and 160 wipe samples from several surfaces (urine/drainage bags, floors, gloves) were taken during the study period. RESULTS: In urine, the highest platinum concentrations were measured on the first day after perfusion. Median platinum concentrations were 1260 ng/ml for patients after cisplatin perfusion and 11,000 ng/ml for oxaliplatin treatment. Concentrations decreased until day three to 413 ng/ml cisplatin and 529 ng/ml oxaliplatin, respectively. In drainage liquids, platinum concentrations were generally lower. Platinum concentrations from surfaces of bags and floors ranged from 0.01 to 439 pg/cm(2) (median: urine bag 2.77 pg/cm(2), drainage bag 0.22 pg/cm(2), floor left 0.14 pg/cm(2), floor right 0.24 pg/cm(2)), with the highest contamination found on the outer surface of the urine bags. Samples from nurses' protective gloves ranged between 0.03 and 12 pg/cm(2) (median: 0.2 pg/cm(2)). CONCLUSIONS: High platinum-drug concentrations in urine and drainage liquids are the main source of contamination. Therefore, safe handling of these liquids is the best way to avoid cross-contamination on surfaces in wards and ICUs. Our results show that it is possible to take care of HIPEC patients without high contaminations during the first 3 days.

Should ALPPS be Used for Liver Resection in Intermediate-Stage HCC?

BACKGROUND: Extended liver resections in patients with hepatocellular carcinoma (HCC) are problematic due to hepatitis, fibrosis, and cirrhosis. Associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) has been promoted as a novel method to induce hypertrophy for patients with extensive colorectal liver metastases, but outcomes in HCC have not been well investigated. METHODS: All patients registered in the international ALPPS Registry ( www.alpps.org ) from 2010 to 2015 were studied. Hypertrophy of the future liver remnant, perioperative morbidity and mortality, age, overall survival, and other parameters were compared between patients with HCC and patients with colorectal liver metastases (CRLM). RESULTS: The study compared 35 patients with HCC and 225 patients with CRLM. The majority of patients undergoing ALPPS for HCC fall into the intermediate-stage category of the Barcelona clinic algorithm. In this study, hypertrophy was rapid and extensive for the HCC patients, albeit lower than for the CRLM patients (47 vs. 76 %; p < 0.002). Hypertrophy showed a linear negative correlation with the degrees of fibrosis. The 90-day mortality for ALPPS used to treat HCC was almost fivefold higher than for CRLM (31 vs. 7 %; p < 0.001). Multivariate analysis showed that patients older than 61 years had a significantly reduced overall survival (p < 0.004). CONCLUSION: The ALPPS approach induces a considerable hypertrophic response in HCC patients and allows resection of intermediate-stage HCC, albeit at the cost of a 31 % perioperative mortality rate. The use of ALPPS for HCC remains prohibitive for most patients and should be performed only for a highly selected patient population younger than 60 years with low-grade fibrosis.

Automated low flow pump system for the treatment of refractory ascites: a single-center experience.

INTRODUCTION: Ascites is a common complication of liver cirrhosis and represents the main cause of hospitalization among patients with cirrhosis. First-line therapy for those patients is the use of diuretics and dietary sodium restriction. However, 10 % of patients per year become therapy refractory to diuretic treatment with the need of repeated high-volume paracentesis or transjugular intrahepatic portosystemic shunt (TIPS). For these patients, an automated pump system (Alfapump/Sequana Medical) was developed. Here, we describe our single-center experience of ten consecutively implanted pump systems. PATIENTS AND METHODS: Between 08/13 and 11/14, ten Alfapump systems were implanted in patients with refractory ascites all suffering from liver cirrhosis. Those patients were treated as a bridge to transplant (4/10) or as an end-stage therapy (6/10). Median follow-up was 165 days (23-379 days). RESULTS: Postimplant, the need of paracentesis could be markedly reduced to a mean of 0.45 (0-4/month) per month. In eight patients, paracentesis was not needed after implantation of the pump system. The median daily output volume was 1000 ml/day (450-2000 ml/day). Prerenal insufficiency was a recurrent complication in the postoperative period. DISCUSSION: The Alfapump system is a useful system in the treatment of patients suffering from therapy refractory ascites. However, due to the high level of comorbidities, careful patient selection and postoperative monitoring are required.

Spiegelmer Inhibition of MCP-1/CCR2--Potential as an Adjunct Immunosuppressive Therapy in Transplantation.

The rejection process remains the key unsolved issue after transplantation of disparate tissue. The CC chemokine monocyte chemoattractant protein-1 (MCP-1/CCL2) has been reported to be involved in the process of alloimmune interaction. Spiegelmers are l-oligonucleotides that can be designed to bind to pharmacologically relevant target molecules. Here, we tested a high-affinity Spiegelmer-based MCP-1 inhibitor (mNOX-E36) in an allogeneic heart transplant model. Fully vascularized allogeneic heterotopic heart transplantations from BALB/c to C57BL/6 mice were performed. Mice were either treated with the anti-MCP-1-Spiegelmer (mNOX-E36) in monotherapy or in combination with subtherapeutic doses of cyclosporine A (CsA) (10 mg/kgBW/day) for 10 days. Controls received equivalent doses of a non-functional Spiegelmer (revmNOX-E36). Graft survival of allogeneic heart transplants was slightly but significantly prolonged under mNOX-E36 monotherapy (median graft survival 10 day ± 0.7) compared to revmNOX-E36 (median graft survival 7 day ± 0.3; P = 0.001). A synergistic beneficial effect could be seen when mNOX-E36 was administered in combination with subtherapeutic doses of CsA (18 day ± 2.8 versus 7 day ± 0.3; P < 0.0001). Levels of inflammatory cytokines and 'alarmins' were significantly reduced, and the number of F4/80(+) cells was lower under combination therapy (1.8% ± 1.3%; versus 14.6% ± 4.4%; P = 0.0002). This novel inhibitor of the MCP-1/CCR2 axis (mNOX-E36), which has already proven efficacy and tolerability in early clinical trials, alleviates acute rejection processes in allogeneic transplantation especially when combined with subtherapeutic doses of CsA. Thus, mNOX-E36 may have potential as an adjunct immunomodulatory agent.

[Requirements for final year medical studies in the era of generation Y - implementation for general and visceral surgery at the Ludwig Maximilians University of Munich]. / Anforderungen an das Praktische Jahr im Zeitalter der Generation Y - Umsetzung für die Allgemein- und Viszeralchirurgie an der Ludwig-Maximilians-Universität München.

The revision of the medical licensing regulations in 2012 has changed the underlying conditions for the practical year (PY), especially in the sense of markedly more flexibility for the medical students. The driving force for these and future changes, however, is not the legislature but rather the students themselves who are explicitly demanding that their training be adapted to their requirements and wishes. Time for the realisation of personal aims, planning of leisure time activities, for the family and social contacts as well as an altogether balanced work-life balance have replaced the wish for professional advancement as premise for the lifestyle of generation Y. Many hospitals, especially the privately-supported, attract students with special offers - university hospitals are called upon to defend their position in the competition for newly qualified students. The present article describes the changes of 2012 as part of a programme for a sustainable increase in the attractivity of the surgical PY at the Ludwig-Maximilian University (LMU) in Munich.

[Systemic therapy and hyperthermia for locally advanced soft tissue sarcoma]. / Systemische Therapie und Hyperthermie beim lokal fortgeschrittenen Weichteilsarkom.

Patients with high-risk soft tissue sarcomas (FNCLCC grades 2-3, > 5 cm and deep lying) are at a high risk of local recurrence or distant metastases despite optimal surgical tumor resection. Therefore, multimodal treatment should be considered for this difficult to treat patient group. Besides surgery, radiation therapy and chemotherapy, hyperthermia has become a valid, complementary treatment option within multimodal treatment concepts. Hyperthermia in this context means the selective heating of the tumor region to temperatures of 40-43 °C for 60 min by microwave radiation in addition to simultaneous chemotherapy or radiation therapy. A randomized phase III study demonstrated that the addition of hyperthermia to neoadjuvant chemotherapy improved tumor response and was associated with a minimal risk of early disease progression as compared to chemotherapy alone. The addition of hyperthermia to a multimodal treatment regimen for high-risk soft tissue sarcoma consisting of surgery, radiation therapy and chemotherapy, either in the neoadjuvant or adjuvant setting after incomplete or marginal tumor resection, significantly improved local progression-free and disease-free survival. Based on these results and due to the generally good tolerability of hyperthermia, this treatment method in combination with chemotherapy should be considered as a standard treatment option within multimodal treatment approaches for locally advanced high-risk soft tissue sarcoma.

[Operative therapy of abdominal and retroperitoneal sarcoma]. / Operative Therapie der abdominellen und retroperitonealen Sarkome.

Retroperitoneal soft tissue sarcomas are characterized by a high rate of local recurrence. Complete tumor resection is the only potentially curative therapeutic option. The concept of a systematic compartmental resection is to remove the tumor en bloc with a margin of uninvolved tissue and organs. This is frequently only achieved by multivisceral resection which often includes kidney, colon, pancreas and parts of the diaphragm or the psoas muscle. The adoption of such a policy of multivisceral organ resection improves the proportion of curative resections and, ultimately, results in lower local recurrence rates. The present article comprehensively describes the operative procedures, perioperative treatment and the oncological results of surgery for retroperitoneal sarcomas. The role of surgery in oncological treatment plans and the importance of specialized centres are outlined in detail.

Resection of pulmonary metastases from colon and rectal cancer: factors to predict survival differ regarding to the origin of the primary tumor.

BACKGROUND: The purpose of the present study was to determine differences in prognostic factors for survival of patients with pulmonary metastases resected in curative intent from colon or rectum cancer. METHODS: Between 1980 and 2006, prognostic factors after resection of pulmonary metastases in 171 patients with primary rectum or colon tumor were evaluated. Survival of patients after surgical metastasectomy was compared with that of patients receiving standard chemotherapy by matched-pair analysis. RESULTS: Median survival after pulmonary resection was 35.2 months (confidence interval 27.3-43.2). One-, 3-, and 5-year survival for patients following R0 resection was 88.8, 52.1, and 32.9 % respectively. Complete metastasectomy (R0), UICC stage of the primary tumor, pleural infiltration, and hilar or mediastinal lymph node metastases are independent prognostic factors for survival. Matched-pair analysis confirmed that pulmonary metastasectomy significantly improved survival. Although no difference in survival for patients with pulmonary metastases from lower rectal compared to upper rectal or colon cancer was observed, factors to predict survival are different for patients with lower and middle rectal cancer (R0, mediastinal and/or hilar lymph nodes, gender, UICC stage) compared with patients with upper rectal or colon cancer (R0, number of metastases). CONCLUSIONS: Our results indicate that distinct prognostic factors exist for patients with pulmonary metastases from lower rectal compared with upper rectal or colon cancer. This supports the notion that colorectal cancer should not be considered as a single-tumor entity. Metastasectomy, especially after complete resection resulted in a dramatic improvement of survival compared with patients treated with chemotherapy alone.

Recombinant TIMP-1-GPI inhibits growth of fibrosarcoma and enhances tumor sensitivity to doxorubicin.

Fibrosarcomas show a high incidence of recurrence and general resistance to apoptosis. Limiting tumor regrowth and increasing their sensitivity to chemotherapy and apoptosis represent key issues in developing more effective treatments of these tumors. Tissue inhibitor of metalloproteinase 1 (TIMP-1) broadly blocks matrix metalloproteinase (MMP) activity and can moderate tumor growth and metastasis. We previously described generation of a recombinant fusion protein linking TIMP-1 to glycosylphophatidylinositol (GPI) anchor (TIMP-1-GPI) that efficiently directs the inhibitor to cell surfaces. In the present report, we examined the effect of TIMP-1-GPI treatment on fibrosarcoma biology. Exogenously applied TIMP-1-GPI efficiently incorporated into surface membranes of human HT1080 fibrosarcoma cells. It inhibited their proliferation, migration, suppressed cancer cell clone formation, and enhanced apoptosis. Doxorubicin, the standard chemotherapeutic drug for fibrosarcoma, was tested alone or in combination with TIMP-1-GPI. In parallel, the influence of treatment on HT1080 side population cells (exhibiting tumor stem cell-like characteristics) was investigated using Hoechst 33342 staining. The sequential combination of TIMP-1-GPI and doxorubicin showed more than additive effects on apoptosis, while TIMP-1-GPI treatment alone effectively decreased "stem-cell like" side population cells of HT1080. TIMP-1-GPI treatment was validated using HT1080 fibrosarcoma murine xenografts. Growing tumors treated with repeated local injections of TIMP-1-GPI showed dramatically inhibited fibrosarcoma growth and reduced angiogenesis. Intraoperative peritumoral application of GPI-anchored TIMP-1 as an adjuvant to surgery may help maintain tumor control by targeting microscopic residual fibrosarcoma cells and increasing their sensitivity to chemotherapy.