Mesenchymal stromal cell mutations and wound healing contribute to the etiology of desmoid tumors

Gamma-Secretase Inhibitors Downregulate the Profibrotic NOTCH Signaling Pathway in Recessive Dystrophic Epidermolysis Bullosa

Recessive dystrophic epidermolysis bullosa (RDEB) is a rare skin fragility disorder caused by mutations in COL7A1. RDEB is hallmarked by trauma-induced unremitting blistering, chronic wounds with inflammation, and progressive fibrosis, leading to severe disease complications. There is currently no cure for RDEB-associated fibrosis. Our previous studies and increasing evidence highlighted the profibrotic role of NOTCH pathway in different skin disorders, including RDEB. In this study, we further investigated the role of NOTCH signaling in RDEB pathogenesis and explored the effects of its inhibition by γ-secretase inhibitors DAPT and PF-03084014 (nirogacestat). Our analyses demonstrated that JAG1 and cleaved NOTCH1 are upregulated in primary RDEB fibroblasts (ie, RDEB-derived fibroblasts) compared with controls, and their protein levels are further increased by TGF-β1 stimulation. Functional assays unveiled the involvement of JAG1/NOTCH1 axis in RDEB fibrosis and demonstrated that its blockade counteracts a variety of fibrotic traits. In particular, RDEB-derived fibroblasts treated with PF-03084014 showed (i) a significant reduction of contractility, (ii) a diminished secretion of TGF-β1 and collagens, and (iii) the downregulation of several fibrotic proteins. Although less marked than PF-03084014-treated cells, RDEB-derived fibroblasts exhibited a reduction of fibrotic traits also upon DAPT treatment. This study provides potential therapeutic strategies to antagonize RDEB fibrosis onset and progression.

Desmoid-type fibromatosis: Current therapeutic strategies and future perspectives

Desmoid tumors (DT) are rare, slow-growing, locally invasive soft tissue tumors that often pose significant therapeutic challenges. Traditional management strategies including active surveillance, surgery, radiotherapy, and systemic therapy which are associated with varying recurrence rates and high morbidity. Given the challenging nature of DT and the modest outcomes associated with current treatment strategies, there has been a growing interest in the field of γ-secretase inhibitors as a result of its action on the Wnt/β-catenin signaling pathway. In this review article, we will shed the light on the pathogenesis and molecular biology of DT, discuss its symptoms and diagnosis, and provide a comprehensive review of the traditional therapeutic approaches. We will also delve into the mechanisms of action of γ-secretase inhibitors, its efficacy, and the existing preclinical and clinical data available to date on the use of these agents, as well as the potential challenges and future prospects in the treatment landscape of these tumors.

Novel insights into biomarkers of progression in Desmoid tumor

Desmoid tumor (DT) is a rare neoplasm characterized by the proliferation of myofibroblastic cells that infiltrates and invades adjacent tissues. Due to its locally aggressive and recurrent nature, DT often causes local symptoms and can be challenging to manage clinically. Therefore, identifying biomarkers that can predict the progression of DT and guide treatment decisions is critical. This review summarizes several biomarkers that have been implicated in active surveillance (AS) and the prediction of postoperative recurrence and attempts to elucidate their underlying mechanisms. Some of these novel markers could provide prognostic value for clinicians, and ultimately help facilitate optimal and accurate therapeutic decisions for DT.

Nirogacestat, a γ-Secretase Inhibitor for Desmoid Tumors

BACKGROUND

Desmoid tumors are rare, locally aggressive, highly recurrent soft-tissue tumors without approved treatments.

METHODS

We conducted a phase 3, international, double-blind, randomized, placebo-controlled trial of nirogacestat in adults with progressing desmoid tumors according to the Response Evaluation Criteria in Solid Tumors, version 1.1. Patients were assigned in a 1:1 ratio to receive the oral γ-secretase inhibitor nirogacestat (150 mg) or placebo twice daily. The primary end point was progression-free survival.

RESULTS

From May 2019 through August 2020, a total of 70 patients were assigned to receive nirogacestat and 72 to receive placebo. Nirogacestat had a significant progression-free survival benefit over placebo (hazard ratio for disease progression or death, 0.29; 95% confidence interval, 0.15 to 0.55; P<0.001); the likelihood of being event-free at 2 years was 76% with nirogacestat and 44% with placebo. Between-group differences in progression-free survival were consistent across prespecified subgroups. The percentage of patients who had an objective response was significantly higher with nirogacestat than with placebo (41% vs. 8%; P<0.001), with a median time to response of 5.6 months and 11.1 months, respectively; the percentage of patients with a complete response was 7% and 0%, respectively. Significant between-group differences in secondary patient-reported outcomes, including pain, symptom burden, physical or role functioning, and health-related quality of life, were observed (P≤0.01). Frequent adverse events with nirogacestat included diarrhea (in 84% of the patients), nausea (in 54%), fatigue (in 51%), hypophosphatemia (in 42%), and maculopapular rash (in 32%); 95% of adverse events were of grade 1 or 2. Among women of childbearing potential receiving nirogacestat, 27 of 36 (75%) had adverse events consistent with ovarian dysfunction, which resolved in 20 women (74%).

CONCLUSIONS

Nirogacestat was associated with significant benefits with respect to progression-free survival, objective response, pain, symptom burden, physical functioning, role functioning, and health-related quality of life in adults with progressing desmoid tumors. Adverse events with nirogacestat were frequent but mostly low grade. (Funded by SpringWorks Therapeutics; DeFi ClinicalTrials.gov number, NCT03785964.).

IPAA Is More "Desmoidogenic" Than Ileorectal Anastomosis in Familial Adenomatous Polyposis

BACKGROUND

Desmoid disease is a leading cause of morbidity and mortality in patients with familial adenomatous polyposis. Abdominal desmoid disease usually follows total proctocolectomy with IPAA or total abdominal colectomy with ileorectal anastomosis. Sex, extraintestinal manifestations, and a 3'-mutation location have been identified as risk factors, but surgical risk factors are poorly understood. We hypothesized that pouch construction creates a higher risk of desmoid formation due to the increased stretch of the small-bowel mesentery.

OBJECTIVE

This study aimed to investigate the surgical risk factors for desmoid formation.

DESIGN

This was a retrospective, single-center, registry-based cohort study.

SETTINGS

This study was conducted at a single academic institution with a prospectively maintained hereditary colorectal cancer database between 1995 and 2015.

PATIENTS

All patients with familial polyposis (total 345) who underwent either proctocolectomy with a pouch or colectomy with an ileorectal anastomosis during the study period and met inclusion criteria were selected.

MAIN OUTCOME MEASURES

The development of symptomatic abdominal desmoid disease was the primary end point. Associations between desmoid formation and resection type, surgical approach, and other patient factors were analyzed.

RESULTS

A total of 172 (49%) patients underwent proctocolectomy/ileoanal pouch, whereas 173 (51%) underwent total colectomy/ileorectal anastomosis. Overall, 100 (28.9%) developed symptomatic desmoids after surgery. On univariable analysis, open surgery and pouch surgery were associated with desmoid development, along with extracolonic manifestations, family history of desmoids, mutation location, and a high desmoid risk score. On multivarible analysis, proctocolectomy with pouch was most strongly associated with desmoid disease ( p < 0.01).

LIMITATIONS

This study was limited by its retrospective nature, the lack of uniform desmoid screening, and the variable duration of follow-up. Unanalyzed confounding factors include polyposis severity and number of surgeries.

CONCLUSIONS

Patients with polyposis who underwent total proctocolectomy with pouch by any approach had significantly greater risk of developing desmoid disease than total colectomy with ileorectal anastomosis, even when accounting for other risk factors. See Video Abstract at http://links.lww.com/DCR/B822 .RESULTADOS DE LOS PACIENTES SOMETIDOS A RESECCIÓN INTESTINAL ELECTIVA ANTES Y DESPUÉS DE LA IMPLEMENTACIÓN DE UN PROGRAMA DE DETECCIÓN Y TRATAMIENTO DE ANEMIA.

ANTECEDENTES

Se sabe que los pacientes anémicos que se someten a una cirugía electiva de cáncer colorrectal tienen tasas significativamente más altas de complicaciones posoperatorias y peores resultados.

OBJETIVO

Mejorar las tasas de detección y tratamiento de la anemia en pacientes sometidos a resecciones electivas de colon y recto a través de una iniciativa de mejora de calidad.

DISEO

Comparamos una cohorte histórica de pacientes antes de la implementación de nuestro programa de detección de anemia y mejora de la calidad del tratamiento con una cohorte prospectiva después de la implementación.

ENTORNO CLINICO

Hospital de atención terciaria.

PACIENTES

Todos los pacientes adultos con un nuevo diagnóstico de cáncer de colon o recto sin evidencia de enfermedad metastásica entre 2017 y 2019.

INTERVENCIONES

Detección de anemia y programa de mejora de la calidad del tratamiento.

PRINCIPALES MEDIDAS DE RESULTADO

El resultado primario fue el costo hospitalario por ingreso.

RESULTADOS

Un total de 84 pacientes se sometieron a resección electiva de colon o recto antes de la implementación de nuestro proyecto de mejora de calidad de la anemia y 88 pacientes se sometieron a cirugía después. En la cohorte previa a la implementación, 44/84 (55,9 %) presentaban anemia en comparación con 47/99 (54,7 %) en la cohorte posterior a la implementación. Las tasas de detección (25 % a 86,4 %) y tratamiento (27,8 % a 63,8 %) aumentaron significativamente en la cohorte posterior a la implementación. El costo total medio por admisión se redujo significativamente en la cohorte posterior a la implementación (costo medio $16 827 vs. $25 796, p = 0,004); esta reducción significativa se observó incluso después de ajustar los factores de confusión relevantes (proporción de medias: 0,74, IC del 95 %: 0,65 a 0,85). El vínculo mecánico entre el tratamiento de la anemia y la reducción de costos sigue siendo desconocido. No hubo diferencias significativas en las tasas de transfusión de sangre, complicaciones o mortalidad entre los grupos.

LIMITACIONES

El diseño de antes y después está sujeto a sesgos temporales y de selección.

CONCLUSIONES

Demostramos la implementación exitosa de un programa de detección y tratamiento de anemia. Este programa se asoció con un costo por admisión significativamente reducido. Este trabajo demuestra el valor y los beneficios posibles de la implementación de un programa de detección y tratamiento de la anemia. Consulte Video Resumen en http://links.lww.com/DCR/C15 . (Traducción- Dr. Francisco M. Abarca-Rendon ).

Molecular pathogenesis of desmoid tumor and the role of γ-secretase inhibition

Desmoid tumor (DT) is a rare, soft tissue neoplasm associated with an unpredictable clinical course. Although lacking metastatic potential, DT is often locally aggressive and invasive, causing significant morbidity. Both sporadic DT and familial adenomatous polyposis (FAP)-associated DT are linked to constitutive activation of the Wnt signaling pathway with mutations in the β-catenin oncogene CTNNB1 or the tumor suppressor gene APC, respectively. Cross-talk between the Notch and Wnt pathways, as well as activation of the Notch pathway resulting from dysregulation of the Wnt pathway, suggest a possible therapeutic target for DT. Due to the role γ-secretase plays in Notch signaling through cleavage of the Notch intracellular domain (with subsequent translocation to the nucleus to activate gene transcription), γ-secretase inhibitors (GSIs) have emerged as a potential treatment for DT. Two GSIs, nirogacestat (PF-03084014) and AL102 are in later-stage clinical development; nirogacestat is being evaluated in a phase 3, randomized, placebo-controlled trial while AL102 is being evaluated in a phase 2/3, dose-finding (part A) and placebo-controlled (part B) trial. This review summarizes current understanding of the molecular pathogenesis of DT focusing on dysregulation of the Wnt signaling pathway, crosstalk with the Notch pathway, and the potential therapeutic role for GSIs in DT.

Intraabdominal sporadic desmoid tumors and inflammation: an updated literature review and presentation and insights on pathogenesis of synchronous sporadic mesenteric desmoid tumors occurring after surgery for necrotizing pancreatitis

Sporadic intra-abdominal desmoid tumors are rare and known to potentially occur after trauma including previous surgery, although knowledge of the underlying pathogenetic mechanism is still limited. We reviewed the recent literature on sporadic intraabdominal desmoids and inflammation as we investigated the mutational and epigenetic makeup of a case of multiple synchronous mesenterial desmoids occurring after necrotizing pancreatitis. A 62-year-old man had four mesenteric masses up to 4.8 cm diameter detected on CT eighteen months after laparotomy for peripancreatic collections from necrotizing pancreatitis. All tumors were excised and diagnosed as mesenteric desmoids. DNA from peripheral blood was tested for a multigene panel. The tumour DNA was screened for three most frequent β-catenin gene mutations T41A, S45F and S45P. Expression levels of miR-21-3p and miR-197-3-p were compared between the desmoid tumors and other wild-type sporadic desmoids. The T41A CTNNB1 mutation was present in all four desmoid tumors. miR-21-3p and miR-197-3p were respectively upregulated and down-regulated in the mutated sporadic mesenteric desmoids, with respect to wild-type lesions. The patient is free from recurrence 34 months post-surgery. The literature review did not show similar studies. To our knowledge, this is the first study to interrogate genetic and epigenetic signature of multiple intraabdominal desmoids to investigate potential association with abdominal inflammation following surgery for necrotizing pancreatitis. We found mutational and epigenetic features that hint at potential activation of inflammation pathways within the desmoid tumor.

Metachronous Sporadic Desmoid Tumors Arisen in the Stomach and the Cecum

Desmoid-type fibromatosis (DF) is a rare soft-tissue tumor demonstrating fibroblastic to myofibroblastic differentiation, recognized as a biologically intermediate, locally aggressive tumor; however, it can be clinically lethal due to its infiltrative growth and risk of locoregional recurrence. Desmoid-type fibromatoses can arise from any part of the body, however, intra-abdominal DFs comprise only 8% of all DFs. We report a case of a male in his 60s who presented with the metachronous occurrence of DF: gastric DF followed by cecal DF with two years of clinical interval. The latter tumor (cecal DF) developed under scheduled postoperative surveillance of laparoscopic gastrectomy. Although a surgical wound is known to be an inductive factor for DFs, the cecal DF developed in a part that was not a surgical site in the previous operation. Curative resection is the first treatment option when the tumor shows progression in size. Following the curative resection, close observation should be provided because of the risk of locoregional recurrence.

Wnt-Independent and Wnt-Dependent Effects of APC Loss on the Chemotherapeutic Response

Resistance to chemotherapy occurs through mechanisms within the epithelial tumor cells or through interactions with components of the tumor microenvironment (TME). Chemoresistance and the development of recurrent tumors are two of the leading factors of cancer-related deaths. The Adenomatous Polyposis Coli (APC) tumor suppressor is lost in many different cancers, including colorectal, breast, and prostate cancer, and its loss correlates with a decreased overall survival in cancer patients. While APC is commonly known for its role as a negative regulator of the WNT pathway, APC has numerous binding partners and functional roles. Through APC's interactions with DNA repair proteins, DNA replication proteins, tubulin, and other components, recent evidence has shown that APC regulates the chemotherapy response in cancer cells. In this review article, we provide an overview of some of the cellular processes in which APC participates and how they impact chemoresistance through both epithelial- and TME-derived mechanisms.

Does ileoanal pouch surgery increase the risk of desmoid in patients with familial adenomatous polyposis?

PURPOSE

Patients with familial adenomatous polyposis (FAP) may undergo either ileorectal anastomosis (IRA) or ileal pouch anal anastomosis (IPAA) depending on the degree of rectal involvement. Desmoid tumors (DTs) may arise postoperatively. Whether IPAA is associated with a higher risk of DTs as compared with IRA remains controversial. The purpose of this study was to determine whether IPAA increased the risk of DTs by analyzing the published data that compared IRA and IPAA as the primary treatment for FAP.

METHODS

A metaanalysis was performed to analyze the published data between 1989 and 2019. IRA and IPAA were compared with respect to the incidence of DTs.

RESULTS

Eight retrospective studies with a total of 1072 patients were identified: 491 underwent IPAA and 581 IRA. There was no significant difference in the incidence of DTs between IPAA and IRA (11.81% vs. 9.47%, OR 0.95, P = 0.85). Meanwhile, the overall complication (42.97% vs. 36.76%, OR 1.32, P = 0.11), incidence of cancer (4.88% vs. 8.37%, OR 0.28, P = 0.26), and overall mortality (0.33% vs. 5.20%, OR 0.49, P = 0.53) were comparable too.

CONCLUSION

Ileoanal pouch surgery is associated with similar risk of desmoid in patients with FAP after surgery.

The role of miRNA-133b and its target gene SIRT1 in FAP-derived desmoid tumor

Signaling pathways have a key role in driving the uncontrolled development of familial adenomatous polyposis (FAP)- associated and sporadic desmoid tumors (DTs).

The relationship between the Wnt/b-catenin signaling pathway and DTs has been extensively studied, but no reliable biomarkers able to detect their histological subtype have been identified for the accurate diagnosis.

In this study we studied the differences in miRNA expression between sporadic (20 patients) and FAP-associated DTs (7 patients) using microarray confirmed by quantitative PCR (qPCR). The analysis showed 19 dysregulated miRNAs. Among them miR-133b levels were significantly lower in FAP-associated DT than in sporadic DT. Therefore, two mRNAs, associated to miR-133b and β-catenin expression, the SIRT1 and ELAVL1were analyzed.

The qPCR analysis showed that SIRT1 mRNA levels were significantly up-regulated in FAP-associated DT than in sporadic DT, whereas no differences in ELAVL1 expression was observed between these two DT types. In addition, a negative correlation was observed between miR-133b and SIRT1 in FAP-associated DTs, but not in sporadic DTs.

The miR-133b-SIRT1-β-catenin axis may represent a novel mechanism underlying progression of FAP-associated DT.

[Long-term effectiveness of "West China Classification" guided surgical treatment of desmoid-type fibromatosis in shoulder girdle]

Objective

To evaluate the long-term effectiveness of patients received surgical treatment under the guidance of "West China Classification" of desmoid-type fibromatosis (DTF) in the shoulder girdle.

Methods

The clinical data of 32 patients with DTF in the shoulder girdle admitted between June 2003 and December 2016 were retrospectively analyzed, including 14 males and 18 females, aged 14-56 years with an average age of 36.8 years. The maximum diameter of the tumor was 7-19 cm, with an average of 11.1 cm. According to the "West China Classification" of DTF in the shoulder girdle, there were 4 cases of region Ⅰ, 3 cases of region Ⅱ, 6 cases of region Ⅲ, 3 cases of region Ⅳ, 5 cases of regions Ⅰ+Ⅱ, 5 cases of regions Ⅱ+Ⅲ, and 6 cases of regions Ⅰ+Ⅱ+Ⅲ. In addition, the involvement of blood vessels and nerves was also taken into consideration for choosing a surgical approach. Finally, 12 cases were operated via anteroposterior approach (group A), 14 via posterior approach (group B), and 6 via combined anterior-posterior approach (group C). The 1993 Musculoskeletal Tumor Society (MSTS93) score (including pain, limb function, satisfaction, hand position, hand flexibility, and lifting ability), Japanese Orthopedic Association (JOA) score, range of motion (ROM) of shoulder joint (including flexion, extension, abduction, and adduction), and complications of patients in the 3 groups were recorded and compared.

Results

All the 32 patients were followed up 30-190 months, with an average of 94.6 months. At last follow-up, complications occurred in 5 cases (15.6%), including 2 cases (16.6%) in group A, 2 (14.3%) in group B, and 1 (16.6%) in group C. There was no significant difference in the incidence of complications among the 3 groups ( P=1.000). Tumor recurrence occurred in 5 (15.6%) cases, including 1 (8.3%) case in group A, 2 (14.3%) in group B, and 1 (16.6%) in group C. No significant difference was found in the recurrence rate among the 3 groups ( P=1.000). At last follow-up, MSTS93 score of pain, limb function, satisfaction, hand flexibility, and hand position in groups A and B were significantly better than those in group C ( P<0.05), even though no significant difference existed between group A and group B ( P>0.05). The lifting ability score in group C was significantly lower than in group A ( P<0.05), and no significant difference was found between other groups ( P>0.05). The JOA score and flexion, extension, abduction, and adduction activities of shoulder in groups A and B were significantly better than those in group C ( P<0.05). The extension activity in group A was significantly better than that in group B ( P<0.05), the flexion activity in group B was significantly better than that in group A ( P<0.05). There was no significant difference in other indexes between groups A and B ( P>0.05).

Conclusion

Taking a rational approach to fully expose and completely remove the tumor is the key point of surgical treatment for patients with DTF in the shoulder girdle. At the same time, preservation of vital structures and reconstruction of soft tissues should also be taken into consideration. Overall, surgical treatment under the guidance of "West China Classification" of DTF in the shoulder girdle has achieved satisfactory long-term effectiveness.

[Biology and signaling pathways involved in the oncogenesis of desmoid tumors]

Desmoid tumors (TDs) are derived from mesenchymal stem cells and their pathogenesis is strongly linked to the Wingless/Wnt cascade where the deregulation of β-catenin plays a major role. A mutation of the CTNNB1 encoding β-catenin is found in the majority of sporadic TD cases and constitutional mutations of APC have been described in heritable forms in patients with familial adenomatous polyposis (FAP). Estrogens could also play a role in pathogenesis and this is the basis for the use of hormone therapy. Other signaling pathways have been involved in the development of TDs such as Notch, Hedgehog, JAK/STAT, PI3 Kinase/AKT and mTOR. Metalloproteases are expressed in TDs and play a role in invasiveness. TGF-ß, as a growth factor, stimulates the transcriptional activity of β-catenin. Future studies will need to focus on better describing and understanding the immune environment of TDs. One of the major difficulties for the experimental study of TDs is the virtual absence of a preclinical model, either in vitro or in vivo. This is partly why the interactions between the different signaling pathways presented here and their consequences for the development of TDs are still poorly understood.

Rapidly Growing Desmoid-Type Fibromatosis of the Mesentery of the Small Intestine after Distal Gastrectomy for Gastric Cancer

We report the case of a 55-year-old man with a surgical history of distal gastrectomy with Roux-en-Y reconstruction performed 3 years prior to the present episode. During the follow-up, a newly developed, rapidly growing intraabdominal mass was detected in the mesentery of the small intestine. Although the patient had been asymptomatic, surgical resection was planned with the suspicion of malignancy, especially lymph node recurrence of the gastric cancer, owing to its rapid growth. Laparotomy showed that the tumor was located in the mesentery of the small intestine near the Roux-en-Y limb, and due to the involvement of the feeding vessels to the Roux-en-Y limb, the anastomotic site was resected en bloc with the tumor, and the whole Roux-en-Y limb was reconstructed. The histopathological finding was compatible with desmoid-type fibromatosis of the mesentery of the small intestine. Here we report our case and discuss the previously reported literature, especially related to gastric cancer.

Clinicopathological characteristics, treatment, and survival outcomes of retroperitoneal desmoid-type fibromatosis: A single-institution experience in China

Retroperitoneal desmoid-type fibromatosis (RPDF) is a rare mesenchymal neoplasm, and it covers a broad spectrum of aggressive monoclonal, fibroblastic proliferation. There is no evidence-based or established optimal treatment available for this intriguing disease yet. Therefore, we here investigated the clinicopathological characteristics, surgical, and survival outcomes in RPDF among Chinese patients.Patients with histologically confirmed RPDF were retrospectively studied from 2010 to 2018 within the West China Hospital of Sichuan University. Demographics, clinicopathological characteristics, treatment, and survival outcome data were collected.Of the 29 cases of RPDF, 19 were females. Tumor diameter ranged from 4 to 40 cm, with a median of 10 cm. Of these patients, surgical resection was the primary treatment adopted for RPDF in 26 cases; while 3 patients underwent watchful waiting. In surgical group, complete and incomplete macroscopic resection was achieved in 21 (80.77%) and 6 (19.23%) cases, respectively. Totally, 21 (80.77%) cases underwent multi-visceral resection. With a median follow-up duration of 48 months, 11 patients experienced tumor progression for the entire cohort. Tumor progression was observed for those patients with incomplete and complete macroscopic resection in 2/5 (40.0%) and 6/21 (28.6%) cases, respectively. In the watchful waiting group, there were no documented cases of RPDF regression. The progression-free survival rate was 86.1%, 71.5%, and 62.3% at 1-, 2-, and 3-years, respectively.RPDFs are rare types of tumor, which have characteristically varied natural histories. Surgical resection had a relative favorable outcome, but some patients were associated with burden of significant surgical complications.

Activated Signaling Pathways and Targeted Therapies in Desmoid-Type Fibromatosis: A Literature Review

Desmoid-type fibromatosis (DTF) is a rare, soft tissue tumor of mesenchymal origin which is characterized by local infiltrative growth behavior. Besides “wait and see,” surgery and radiotherapy, several systemic treatments are available for symptomatic patients. Recently, targeted therapies are being explored in DTF. Unfortunately, effective treatment is still hampered by the limited knowledge of the molecular mechanisms that prompt DTF tumorigenesis. Many studies focus on Wnt/β-catenin signaling, since the vast majority of DTF tumors harbor a mutation in the CTNNB1 gene or the APC gene. The established role of the Wnt/β-catenin pathway in DTF forms an attractive therapeutic target, however, drugs targeting this pathway are still in an experimental stage and not yet available in the clinic. Only few studies address other signaling pathways which can drive uncontrolled growth in DTF such as: JAK/STAT, Notch, PI3 kinase/AKT, mTOR, Hedgehog, and the estrogen growth regulatory pathways. Evidence for involvement of these pathways in DTF tumorigenesis is limited and predominantly based on the expression levels of key pathway genes, or on observed clinical responses after targeted treatment. No clear driver role for these pathways in DTF has been identified, and a rationale for clinical studies is often lacking. In this review, we highlight common signaling pathways active in DTF and provide an up-to-date overview of their therapeutic potential.

Understanding the cancer stem cell phenotype: A step forward in the therapeutic management of cancer

The experimental validation of the existence of cancer stem cells (CSC) has had a significant impact on our understanding of the cellular mechanisms and signaling networks involved in the process of carcinogenesis and its progression. These findings provide insights into the critical role that tumor microenvironment and metabolism play in the acquisition of the drug resistance phenotype as well as provide potential targets for therapeutic exploitation. Here we briefly review the literature on the involvement of key signaling pathways such as Wnt/β-catenin, Notch, Hedgehog and STAT3 in the appearance of cancer cells with stem cells-like characteristics. In addition, we also highlight some of the recent therapeutic strategies used to target these pathways as well as approaches aiming to specifically target CSCs through their distinctive metabolic features.

Clinical prognostic factors for pediatric extra-abdominal desmoid tumor: analyses of 66 patients at a single institution

Background and purpose

Pediatric desmoid tumor (PDT) is rare and has a high local recurrence rate. The purpose of the present study was to analyze clinical risk factors of local recurrence in PDT patients.

Materials and methods

We reviewed clinical data of 66 PDT patients from 2004 to 2015. All patients underwent macroscopically complete resection, and some recurrent tumors were prescribed radiotherapy. Factors such as sex, age at presentation, location, and proximity to nerves or vasculature were analyzed. The local recurrence rate and recurrence-free survival were analyzed with these factors.

Results

All patients in the present study were children and had extra-abdominal tumors. The median follow-up time was 6.6 years. Thirty-six (55%) patients had local recurrence. Age, sex, tumor site, tumor size, and proximity to nerves/vasculature had a significant impact on prognosis in univariate analysis. Radiotherapy decreased the local recurrence rate. In multivariate analysis, younger age, tumor location in buttocks, larger tumor, and proximity to important nerves/vasculature were independent risk factors for poor prognosis.

Conclusions

Favorable therapeutic strategies could be selected according to the preoperative prognostic risk factors. Radiotherapy should be considered for local recurrence of PDT.

Surgical excision versus observation as initial management of desmoid tumors: A population based study

SYNOPSIS

Desmoid tumors can be safely managed with watchful waiting, including either observation alone or tamoxifen/NSAIDs. Surgery at first presentation can be associated with significant treatment burden.

BACKGROUND

Immediate surgery was historically recommended for desmoid tumors. Recently, watchful waiting, (tamoxifen/NSAIDs or observation alone), has been advocated.

METHODS

All diagnoses of desmoid tumor within the Alberta Cancer Registry from August 2004 to September 2015 were identified. Patients with FAP were excluded. Demographics, tumor characteristics and treatment and outcome data were collected. Outcomes were compared between immediate surgery and watchful waiting. The effect of abdominal wall site on progression and recurrence and the effect of microscopic margin on recurrence were assessed with Fisher's exact test.

RESULTS

We identified 111 non-FAP patients. Median follow-up was 35 months from diagnosis. 74% were female. Mean age was 42. Fifty (45%) underwent watchful waiting, of whom 21(42%) progressed, with median PFS of 10 months. Fifty-three (48%) underwent resection at presentation, of whom 8 (15%) recurred, with median disease-free survival of 22 months. Abdominal wall lesions were equally represented in both groups, and equally likely to progress on watchful waiting (50% vs 39%, p = 0.53), but there was a trend toward decreased recurrence after surgery. (5% vs 23%, p = 0.08). Microscopic margin had no effect on recurrence (14% of margin negative vs 20% of margin positive, p = 1.0).

CONCLUSIONS

Watchful waiting was successful in 58% of patients, and a further 28% only required one aggressive treatment thereafter, for a total of 86%. Surgery had a favorable recurrence rate (15%), but some recurrences were associated with significant treatment burden. Treatment should be tailored to individual patients in a multidisciplinary setting. A trial of observation appears warranted in most patients. Recurrence rate was not affected by positive margins.

Mesenchymal stromal cell engagement in cancer cell epithelial to mesenchymal transition

Due to coexistence of stromal and epithelial tumor cells, their dynamic interactions have been widely recognized as significant cellular components to the tumor tissue integrity. Initiation and outcome of epithelial to mesenchymal transition (EMT) in tumor cells are dependent on their interaction with adjacent or recruited mesenchymal stromal cells (MSCs). A plethora of mechanisms are involved in MSCs-controlled employment of the developmental processes of EMT that contribute to loss of epithelial cell phenotype and acquisition of stemness, invasiveness and chemoresistance of tumor cells. Interplay of MSCs with tumor cells, including interchange of soluble biomolecules, plasma membrane structures, cytoplasmic content, and organelles, is established through cell-cell contact and/or by means of paracrine signaling. The main focus of this review is to summarize knowledge about involvement of MSCs in cancer cell EMT. Understanding the underlying cellular and molecular mechanism involved in the interplay between MSCs and cancer EMT is essential for development of effective therapy approaches, which in combination with current treatments may improve the control of tumor progression. Developmental Dynamics 247:359-367, 2018. © 2017 Wiley Periodicals, Inc.

Embryotoxicity Caused by DON-Induced Oxidative Stress Mediated by Nrf2/HO-1 Pathway

Deoxynivalenol (DON) belongs to the type B group of trichothecenes family, which is composed of sesquiterpenoid metabolites produced by Fusarium and other fungi in grain. DON may cause various toxicities, such as cytotoxicity, immunotoxicity, genotoxicity as well as teratogenicity and carcinogenicity. In the present study, we focus on a hypothesis that DON alters the expressions of Nrf2/HO-1 pathway by inducing embryotoxicity in C57BL/6 mouse (5.0, 2.5, 1.0, and 0 mg/kg/day) and BeWo cell lines (0 and 50 nM; 3 h, 12 h and 24 h). Our results indicate that DON treatment in mice during pregnancy leads to ROS accumulation in the placenta, which results in embryotoxicity. At the same time Nrf2/HO-1 pathway is up-regulated by ROS to protect placenta cells from oxidative damage. In DON-treated BeWo cells, the level of ROS has time–effect and dose–effect relationships with HO-1 expression. Moderate increase in HO-1 protects the cell from oxidative damage, while excessive increase in HO-1 aggravates the oxidative damage, which is called in some studies the “threshold effect”. Therefore, oxidative stress may be the critical molecular mechanism for DON-induced embryotoxicity. Besides, Nrf2/HO-1 pathway accompanied by the “threshold effect” also plays an important role against DON-induced oxidative damage in this process.

Biology and Treatment of Aggressive Fibromatosis or Desmoid Tumor

Aggressive fibromatosis, also known as desmoid-type fibromatosis (DTF) or desmoid tumor, is an uncommon locally invasive tumor. Because of its low incidence and variable behavior, DTF is often first seen by physicians who are not familiar with it, and recent advances in understanding this disease have led to changes in treatment approaches. The Wnt (β-catenin) pathway appears to play a key role in DTF pathogenesis, and recent studies of DTF biology suggest a possible model of DTF pathogenesis. Histologically, DTF shows a poorly circumscribed proliferation of myofibroblast-like cells with variable collagen deposition, similar to the proliferative phase of wound healing, and DTF has been associated with trauma and pregnancy. Desmoid-type fibromatosis may be a useful model of the tumor stroma in carcinomas as well as other fibrosing diseases such as progressive pulmonary fibrosis. The clinical course of DTF can vary greatly among patients, complicating the determination of the optimal treatment approach. Treatment options include surgery, nonsteroidal anti-inflammatory drugs with or without hormonal manipulation, chemotherapy, radiation therapy, and other forms of local therapy. Many treatments have been used, but these are not without toxicities. Because of the variable nature of the disease and the potential morbidity of treatment, some cases of DTF may do better without treatment; simple observation is often the best initial treatment. This review used a PubMed search from January 1, 1980, through October 31, 2016, using the terms fibromatosis and desmoid and discusses DTF disease characteristics, pathophysiology, and treatment options as well as examines several cases illustrating key points in the biology and treatment of this heterogeneous disease.

The role of S100a4 (Mts1) in Apc- and Smad4-driven tumour onset and progression

INTRODUCTION

S100a4 is a calcium-binding protein belonging to the family of S100-proteins, highly expressed in different stromal cell types. S100A4 has been reported as a prognostic marker in colorectal cancer in association with tumour progression and metastasis.

METHODS

In this study, we analysed the in vivo role of S100a4 in intestinal tumour initiation and progression using different transgenic and knockout mouse models.

RESULTS

We found that genetic ablation or overexpression of S100a4 in both Apc- and Smad4-mutant mice do not affect tumour initiation in the intestinal tract. In contrast, S100a4 epithelial overexpression in Apc^1638N/+/KRAS^V12G mice increases the dissemination of intestinal tumour cells to the liver, in agreement with its role in tumour metastasis. Moreover, we report a novel role for S100a4 in desmoid formation where S100a4 deficiency results in a significant reduction of the tumour burden characteristic of the Apc^1638N model. In agreement with these results, S100a4 appears to be co-expressed together with mesenchymal stem cell (MSC) markers in desmoid tumours from Apc^1638N/+ mice, as well as from sporadic and hereditary human desmoids.

CONCLUSION

Our data provide the first report on the in vivo role of S100a4 in intestinal tumourigenesis and describe a new role for S100a4 in the aetiology of desmoids formation.

Sporadic desmoid tumors of the abdominal wall: the results of surgery

PURPOSE

Before the wait-and-see policy became the standard approach in abdominal wall desmoid tumors, surgery was performed on a systematic basis. Surgery remains indicated for progressing tumors but its extent is debatable. The abdominal wall is a common site of origin of sporadic desmoids, usually associated with a favorable prognosis. We analyzed the results of surgery at this specific site.

METHODS

Data from 33 patients affected by sporadic desmoid tumors of the abdominal wall (31 primary, 2 recurrent) consecutively treated at our cancer center between January 2000 and September 2013 were retrospectively studied.

RESULTS

Twenty-nine patients underwent surgery upfront and 1 after progression during the initial wait-and-see period. Prosthetic reconstruction of the abdominal wall was required in 28 patients. The average hospital stay was 5 days. Three patients developed surgical complications. Local recurrence-free survival was 90% at 5 and 10 years. Three patients had an uneventful childbirth during the follow-up after surgery.

CONCLUSIONS

Desmoid tumors of the abdominal wall have a favorable prognosis after surgical resection, which remains a safe and effective treatment. Wild-type tumors are common, whereas the incidence of S45F mutation in the beta-catenin gene is lower than in other anatomic sites. Upfront surgery may be considered in selected women who wish to bear a child.

Wnt signaling induces epithelial differentiation during cutaneous wound healing

Cutaneous wound repair in adult mammals typically does not regenerate original dermal architecture. Skin that has undergone repair following injury is not identical to intact uninjured skin. This disparity may be caused by differences in the mechanisms that regulate postnatal cutaneous wound repair compared to embryonic skin development and thus we seek a deeper understanding of the role that Wnt signaling plays in the mechanisms of skin repair in both fetal and adult wounds. The influence of secreted Wnt signaling proteins in tissue homeostasis has galvanized efforts to identify small molecules that target Wnt-mediated cellular responses. Wnt signaling is activated by wounding and participates in every subsequent stage of the healing process from the control of inflammation and programmed cell death, to the mobilization of stem cell reservoirs within the wound site. Endogenous Wnt signaling augmentation represents an attractive option to aid in the restoration of cutaneous wounds, as the complex mechanisms of the Wnt pathway have been increasingly investigated over the years. In this review, we summarize recent data elucidating the roles that Wnt signaling plays in cutaneous wound healing process.

Risk Factors for the Development of Desmoid Tumor After Colectomy in Patients with Familial Adenomatous Polyposis: Multicenter Retrospective Cohort Study in Japan

BACKGROUND

Desmoid tumor (DT) is the primary cause of death in patients with familial adenomatous polyposis (FAP) after restorative proctocolectomy. This study aimed to identify risk factors for DT in a Japanese population.

METHODS

Clinical data for 319 patients with FAP undergoing first colectomy from 2000 to 2012 were reviewed retrospectively.

RESULTS

Two hundred seventy-seven FAP patients were included in this study. Thirty-nine (14.1 %) patients developed DT. Occurrence sites were the intraperitoneal region in 25 (64.1 %) cases, intraperitoneal region and abdominal wall in three (7.7 %), and abdominal wall in nine (23.1 %). The mean period from surgery to DT development was 26.3 months (range 4-120 months). Gender (female vs. male, p = 0.03), age at surgery (>30 vs. ≤30 years, p = 0.02), purpose of surgery (prophylactic vs. cancer excision, p = 0.01), and surgical procedure (proctocolectomy [ileoanal anastomosis (IAA), ileoanal canal anastomosis (IACA), total proctocolectomy (TPC)] vs. total colectomy [ileorectal anastomosis, partial colectomy]; p = 0.03) significantly influenced the estimated cumulative risk of developing DT at 5 years after surgery. Conversely, approach (laparoscopic vs. open, p = 0.17) had no significant effect on the increased risk of DT occurrence. In multivariate analysis, female gender, with a hazard ratio of 2.2 (p = 0.02,) and proctocolectomy (IAA, IACA, TPC), with a hazard ratio of 2.2 (p = 0.03), were independent risk factors for DT incidence after colectomy.

CONCLUSIONS

Female gender and proctocolectomy (IAA, IACA, TPC) were independent risk factors for developing DT after colectomy in patients with FAP.

Desmoid Tumors: A Review of the Literature and Pharmacologic Management

Desmoid tumors represent a nonmalignant proliferation of fibroblast-related cells. These rare tumors are difficult to treat and often persist as indolent, lifelong conditions. There are a number of treatments available for both anatomic and symptom regression. Some of these treatments, unfortunately, may not provide long-lasting results and may result in further complications. Pain is a distressing symptom that may be due to the tumor itself or the result of utilized treatments. Pharmacologic therapies represent a noninvasive alternative to surgical resection. Pain symptoms require therapeutic regimens that must be modified as the tumor evolves in expression. The individualized pain treatment program utilized may often reflect principles used in both nonmalignant and malignant pain management models. This review seeks to increase awareness of desmoid tumors through a review of the literature and discussion of its pharmacotherapeutic management.

Anti-CD73 in cancer immunotherapy: awakening new opportunities

In recent years, cancer immunotherapy made significant advances due to a better understanding of the principles underlying tumor biology and immunology. In this context, CD73 is a key molecule, since via degradation of adenosine monophosphate into adenosine, endorses the generation of an immunosuppressed and pro-angiogenic niche within the tumor microenvironment that promotes the onset and progression of cancer. Targeting CD73 results in favorable antitumor effects in pre-clinical models and combined treatments of CD73 blockade with other immune-modulating agents (i.e. anti-CTLA-4 mAb or anti-PD1 mAb) is particularly attractive. Although there is still a long way to go, anti-CD73 therapy, through the development of CD73 monoclonal antibodies, can potentially constitute a new biologic therapy for cancer patients. In this review, we discuss the link between CD73 and the onset, development and spread of tumors, highlighting the potential value of this molecule as a target and as a novel biomarker in the context of personalized cancer therapy.

Targeting the Notch pathway: A potential therapeutic approach for desmoid tumors

BACKGROUND

Desmoid tumors (DTs) are rare mesenchymal lesions that can recur repeatedly. When it is feasible, DTs are surgically resected; however, this often results in high recurrence rates. Recently, treatment with PF‐03084014, a potent γ‐secretase inhibitor, has been shown to have antitumor activity in several tumor types by affecting the WNT/β‐catenin pathway. Consequently, Notch pathway inhibition by PF‐03084014 might be a promising approach for DT treatment.

METHODS

The expression of Notch pathway components was analyzed in DT tissues and cell strains with immunohistochemistry and Western blotting, respectively. A panel of DT cell strains was exposed to PF‐03084014 and evaluated for cell proliferation. Antitumor effects were assessed via cell cycle, apoptosis, and migration and invasion analysis. Cells treated with PF‐03084014 were characterized with a gene array analysis combined with Ingenuity Pathway Analysis.

RESULTS

The results showed that Notch pathway components were expressed at different levels in DTs. Hes1 (Hes Family BHLH Transcription Factor 1) was overexpressed in DT tumors versus dermal scar tissue, and PF‐03084014 caused significant decreases in Notch intracellular domain and Hes1 expression in DT cell strains. PF‐03084014 decreased DT cell migration and invasion and also caused cell growth inhibition in DT cell strains, most likely through cell cycle arrest. Gene array analysis combined with Ingenuity Pathway Analysis showed that Wnt1‐inducible signaling pathway protein 2 possibly regulated Notch and WNT pathways after treatment with PF‐03084014 through integrin.

CONCLUSION

Our findings suggest that the Notch pathway is an important DT therapeutic target. Furthermore, PF‐03084014 has significant antitumor activity against DTs, and it may be an alternative strategy for DT treatment. Cancer 2015;121:4088–4096. © 2015 American Cancer Society.

The Notch pathway is an important therapeutic target for desmoid tumors, and the γ‐secretase inhibitor PF‐03084014 has significant antitumor activity against desmoid tumors. The use of this inhibitor may be an alternative strategy for desmoid tumor treatment.

Targeting Notch, Hedgehog, and Wnt pathways in cancer stem cells: clinical update

During the past decade, cancer stem cells (CSCs) have been increasingly identified in many malignancies. Although the origin and plasticity of these cells remain controversial, tumour heterogeneity and the presence of small populations of cells with stem-like characteristics is established in most malignancies. CSCs display many features of embryonic or tissue stem cells, and typically demonstrate persistent activation of one or more highly conserved signal transduction pathways involved in development and tissue homeostasis, including the Notch, Hedgehog (HH), and Wnt pathways. CSCs generally have slow growth rates and are resistant to chemotherapy and/or radiotherapy. Thus, new treatment strategies targeting these pathways to control stem-cell replication, survival and differentiation are under development. Herein, we provide an update on the latest advances in the clinical development of such approaches, and discuss strategies for overcoming CSC-associated primary or acquired resistance to cancer treatment. Given the crosstalk between the different embryonic developmental signalling pathways, as well as other pathways, designing clinical trials that target CSCs with rational combinations of agents to inhibit possible compensatory escape mechanisms could be of particular importance. We also share our views on the future directions for targeting CSCs to advance the clinical development of these classes of agents.

Characteristics of mesenchymal stromal cells isolated from patients with breast cancer

Mesenchymal stromal cells were isolated from the adipose tissue obtained during surgery for breast cancer and cultured under conditions of normal or low oxygen concentrations. In patients that had received a course of radiation and polychemotherapy prior to surgery, the proliferative potential of mesenchymal stromal cells was irreversibly disturbed. In patients receiving no therapy prior to surgery, the morphological, growth, phenotypic, and differentiation characteristics of mesenchymal stromal cells did not differ from the corresponding parameters of mesenchymal stromal cells from healthy donors. Culturing under hypoxic conditions increased adipogenic differentiation potencies of mesenchymal stromal cells from donors and patients.

A Phase I, dose-finding study in patients with advanced solid malignancies of the oral γ-secretase inhibitor PF-03084014

PURPOSE

To estimate the maximum tolerated dose (MTD) for continuous oral administration of the γ-secretase inhibitor PF-03084014, determine the recommended phase II dose (RP2D), and evaluate safety and preliminary activity in patients with advanced solid tumors.

EXPERIMENTAL DESIGN

This open-label, phase I study consisted of a dose-finding portion based on a 3+3 design, followed by an expansion cohort. PF-03084014 was administered orally, twice daily (BID) for 21 continuous days. Tested doses ranged from 20 to 330 mg BID. In the expansion cohort, patients were to receive the estimated MTD or a lower dose of PF-03084014.

RESULTS

A total of 64 patients received treatment. The MTD was estimated to be 220 mg BID. The RP2D was determined to be 150 mg BID, based on the better safety profile versus the 220-mg BID dose, given comparable NOTCH-related target inhibition. The most common treatment-related adverse events were diarrhea, nausea, fatigue, hypophosphatemia, vomiting, rash, and decreased appetite, which were generally mild to moderate in severity. One patient with advanced thyroid cancer had a complete response, and five of seven response-evaluable patients with desmoid tumor achieved a partial response (71.4% objective response rate). Tumor responses were mostly durable, ranging from 1.74+ to 24+ months. PF-03084014 demonstrated a generally dose-dependent pharmacokinetic profile at doses ranging from 20 to 330 mg BID. Consistent downmodulation of NOTCH-related HES4 gene expression was observed in peripheral blood from all evaluable patients.

CONCLUSION

Further development of PF-03084014 for the treatment of patients with advanced solid tumors is warranted and currently under evaluation.

Mechanisms of tumor escape from immune system: role of mesenchymal stromal cells

Tumor microenvironment represents the site where the tumor tries to survive and escape from immune system-mediated recognition. Indeed, to proliferate tumor cells can divert the immune response inducing the generation of myeloid derived suppressor cells and regulatory T cells which can limit the efficiency of effector antitumor lymphocytes in eliminating neoplastic cells. Many components of the tumor microenvironment can serve as a double sword for the tumor and the host. Several types of fibroblast-like cells, which herein we define mesenchymal stromal cells (MSC), secrete extracellular matrix components and surrounding the tumor mass can limit the expansion of the tumor. On the other hand, MSC can interfere with the immune recognition of tumor cells producing immunoregulatory cytokines as transforming growth factor (TGF)ß, releasing soluble ligands of the activating receptors expressed on cytolytic effector cells as decoy molecules, affecting the correct interaction among lymphocytes and tumor cells. MSC can also serve as target for the same anti-tumor effector lymphocytes or simply impede the interaction between these lymphocytes and neoplastic cells. Thus, several evidences point out the role of MSC, both in epithelial solid tumors and hematological malignancies, in regulating tumor cell growth and immune response. Herein, we review these evidences and suggest that MSC can be a suitable target for a more efficient anti-tumor therapy.

Sporadic desmoid-type fibromatosis: a stepwise approach to a non-metastasising neoplasm--a position paper from the Italian and the French Sarcoma Group

Desmoid-type fibromatosis (DF) is a rare locally aggressive monoclonal proliferation of myofibroblasts lacking metastatic capacity. It may be observed in nearly every part of the body. Considering the variable clinical presentations, anatomic locations, and biologic behaviors, an individualized treatment approach is required. The pathogenesis of DF is not completely understood even if a high prevalence (∼85%) of CTNNB1 mutations discovered in sporadic DF underlies the importance of the Wnt/β-catenin pathway. No established and evidence-based approach for the treatment of this neoplasm is available as of today. Considering the unpredictable behavior and the heterogeneity of this disease, we propose a treatment algorithm approved by the French and the Italian Sarcoma Group, based on a front-line wait and see approach and subsequent therapy in the case of progression. A careful counseling at a referral center is mandatory and should be offered to all patients affected by sporadic DF from the time of their diagnosis.

Lack of anti-tumor activity with the β-catenin expression inhibitor EZN-3892 in the C57BL/6J Min/+ model of intestinal carcinogenesis

BACKGROUND

Previously, we showed that short-term inhibition of β-catenin expression and reversal of aberrant β-catenin subcellular localization by the selective COX-2 inhibitor celecoxib is associated with adenoma regression in the C57BL/6J Min/+ mouse. Conversly, long-term administration resulted in tumor resistance, leading us to investigate alternative methods for selective β-catenin chemoprevention. In this study, we hypothesized that disruption of β-catenin expression by EZN-3892, a selective locked nucleic acid (LNA)-based β-catenin inhibitor, would counteract the tumorigenic effect of Apc loss in Min/+ adenomas while preserving normal intestinal function.

MATERIALS AND METHODS

C57BL/6J Apc(+/+) wild-type (WT) and Min/+ mice were treated with the maximum tolerated dose (MTD) of EZN-3892 (30mg/kg). Drug effect on tumor numbers, β-catenin protein expression, and nuclear β-catenin localization were determined.

RESULTS

Although the tumor phenotype and β-catenin nuclear localization in Min/+ mice did not change following drug administration, we observed a decrease in β-catenin expression levels in the mature intestinal tissue of treated Min/+ and WT mice, providing proof of principle regarding successful delivery of the LNA-based antisense vehicle. Higher doses of EZN-3892 resulted in fatal outcomes in Min/+ mice, likely due to β-catenin ablation in the intestinal tissue and loss of function.

CONCLUSIONS

Our data support the critical role of Wnt/β-catenin signaling in maintaining intestinal homeostasis and highlight the challenges of effective drug delivery to target disease without permanent toxicity to normal cellular function.

Targeting stem cell behavior in desmoid tumors (aggressive fibromatosis) by inhibiting hedgehog signaling

Desmoid tumor (also called aggressive fibromatosis) is a lesion of mesenchymal origin that can occur as a sporadic tumor or a manifestation of the preneoplastic syndrome, familial adenomatous polyposis caused by a mutation in adenomatous polyposis coli (APC). This tumor type is characterized by the stabilization of β-catenin and activation of Tcf-mediated transcription. Cell transplantation data suggest that desmoid tumors are derived from mesenchymal progenitor cells (MSCs). As such, modulating cell signaling pathways that regulate MSC differentiation or proliferation, such as hedgehog (Hh) signaling, could alter the tumor phenotype. Here, we found that Hh signaling is activated in human and murine desmoid tumors. Inhibiting Hh signaling in human cell cultures decreased cell proliferation and β-catenin protein levels. Apc(+)/Apc(1638N) mice, which develop desmoid tumors, develop smaller and fewer tumors when Hh signaling was inhibited either genetically (by crossing Apc(+)/Apc(1638N) mice with mice lacking one copy of a Hh-activated transcription factor, Gli2 (+/-) mice) or using a pharmacologic inhibitor. Both in mice and in human tumor cell cultures, β-catenin and Hh-mediated signaling positively regulate each other's activity. These data show that targeting a pathway that regulates MSC differentiation influences desmoid tumor behavior, providing functional evidence supporting the notion that these tumors are derived from mesenchymal progenitors. It also suggests Hh blockade as a therapeutic approach for this tumor type.

FGFR1-WNT-TGF-β signaling in prostate cancer mouse models recapitulates human reactive stroma

The reactive stroma surrounding tumor lesions performs critical roles ranging from supporting tumor cell proliferation to inducing tumorigenesis and metastasis. Therefore, it is critical to understand the cellular components and signaling control mechanisms that underlie the etiology of reactive stroma. Previous studies have individually implicated fibroblast growth factor receptor 1 (FGFR1) and canonical WNT/β-catenin signaling in prostate cancer progression and the initiation and maintenance of a reactive stroma; however, both pathways are frequently found to be coactivated in cancer tissue. Using autochthonous transgenic mouse models for inducible FGFR1 (JOCK1) and prostate-specific and ubiquitously expressed inducible β-catenin (Pro-Cat and Ubi-Cat, respectively) and bigenic crosses between these lines (Pro-Cat × JOCK1 and Ubi-Cat × JOCK1), we describe WNT-induced synergistic acceleration of FGFR1-driven adenocarcinoma, associated with a pronounced fibroblastic reactive stroma activation surrounding prostatic intraepithelial neoplasia (mPIN) lesions found both in in situ and reconstitution assays. Both mouse and human reactive stroma exhibited increased transforming growth factor-β (TGF-β) signaling adjacent to pathologic lesions likely contributing to invasion. Furthermore, elevated stromal TGF-β signaling was associated with higher Gleason scores in archived human biopsies, mirroring murine patterns. Our findings establish the importance of the FGFR1-WNT-TGF-β signaling axes as driving forces behind reactive stroma in aggressive prostate adenocarcinomas, deepening their relevance as therapeutic targets.

[Intraabdominal desmoid tumors in familial adenomatous polyposis]

Desmoid tumors are currently the main cause of morbidity and mortality in patients with familial adenomatous polyposis. More than 10% of these patients will develop these tumors during their lifetime and more than a third will suffer their consequences. The main risk factors for their development are female sex and abdominal surgery. The most frequent localization is intraabdominal. The therapeutic approach to these tumors has changed, and the surgical treatment of choice is currently the subject of debate. If a watch and wait approach is adopted, more than 50% of tumors will prove to be indolent. Therefore, the therapeutic strategy should be based on clinical presentation and should be decided by a multidisciplinary team working in a center with experience of these tumors. The present article proposes a prognostic classification to guide the therapeutic approach.

Extra-abdominal desmoid tumors associated with familial adenomatous polyposis

Extra-abdominal desmoid tumors are a significant cause of morbidity in patients with familial adenomatous polyposis syndrome. Understanding of the basic biology and natural history of these tumors has increased substantially over the past decade. Accordingly, medical and surgical management of desmoid tumors has also evolved. This paper analyzes recent evidence pertaining to the epidemiology, molecular biology, histopathology, screening, and treatment of extra-abdominal desmoid tumors associated with familial adenomatous polyposis syndrome.

Tumor microenvironment complexity: emerging roles in cancer therapy

The tumor microenvironment (TME) consists of cells, soluble factors, signaling molecules, extracellular matrix, and mechanical cues that can promote neoplastic transformation, support tumor growth and invasion, protect the tumor from host immunity, foster therapeutic resistance, and provide niches for dormant metastases to thrive. An American Association for Cancer Research (AACR) special conference held on November 3-6, 2011, addressed five emerging concepts in our understanding of the TME: its dynamic evolution, how it is educated by tumor cells, pathways of communication between stromal and tumor cells, immunomodulatory roles of the lymphatic system, and contribution of the intestinal microbiota. These discussions raised critical questions on how to include the analysis of the TME in personalized cancer diagnosis and treatment.