Altered muscle niche contributes to myogenic deficit in the D2- mdx model of severe DMD

Lack of dystrophin is the genetic basis for the Duchenne muscular dystrophy (DMD). However, disease severity varies between patients, based on specific genetic modifiers. D2- mdx is a model for severe DMD that exhibits exacerbated muscle degeneration and failure to regenerate even in the juvenile stage of the disease. We show that poor regeneration of juvenile D2- mdx muscles is associated with enhanced inflammatory response to muscle damage that fails to resolve efficiently and supports excessive accumulation of fibroadipogenic progenitors (FAPs). Unexpectedly, the extent of damage and degeneration of juvenile D2- mdx muscle is reduced in adults and is associated with the restoration of the inflammatory and FAP responses to muscle injury. These improvements enhance myogenesis in the adult D2- mdx muscle, reaching levels comparable to the milder (B10- mdx ) mouse model of DMD. Ex vivo co-culture of healthy satellite cells (SCs) with the juvenile D2- mdx FAPs reduced their fusion efficacy and in vivo glucocorticoid treatment of juvenile D2 mouse improved muscle regeneration. Our findings indicate that aberrant stromal cell response contributes to poor myogenesis and greater muscle degeneration in dystrophic juvenile D2- mdx muscles and reversal of this reduces pathology in adult D2- mdx mouse muscle, identifying these as therapeutic targets to treat dystrophic DMD muscles.

Monitoring Therapeutic Response to Anti-FAP CAR T Cells Using [18F]AlF-FAPI-74

PURPOSE

Despite the success of chimeric antigen receptor (CAR) T-cell therapy against hematologic malignancies, successful targeting of solid tumors with CAR T cells has been limited by a lack of durable responses and reports of toxicities. Our understanding of the limited therapeutic efficacy in solid tumors could be improved with quantitative tools that allow characterization of CAR T-targeted antigens in tumors and accurate monitoring of response.

EXPERIMENTAL DESIGN

We used a radiolabeled FAP inhibitor (FAPI) [18F]AlF-FAPI-74 probe to complement ongoing efforts to develop and optimize FAP CAR T cells. The selectivity of the radiotracer for FAP was characterized in vitro, and its ability to monitor changes in FAP expression was evaluated using rodent models of lung cancer.

RESULTS

[18F]AlF-FAPI-74 showed selective retention in FAP+ cells in vitro, with effective blocking of the uptake in presence of unlabeled FAPI. In vivo, [18F]AlF-FAPI-74 was able to detect FAP expression on tumor cells as well as FAP+ stromal cells in the tumor microenvironment with a high target-to-background ratio. We further demonstrated the utility of the tracer to monitor changes in FAP expression following FAP CAR T-cell therapy, and the PET imaging findings showed a robust correlation with ex vivo analyses.

CONCLUSIONS

This noninvasive imaging approach to interrogate the tumor microenvironment represents an innovative pairing of a diagnostic PET probe with solid tumor CAR T-cell therapy and has the potential to serve as a predictive and pharmacodynamic response biomarker for FAP as well as other stroma-targeted therapies. A PET imaging approach targeting FAP expressed on activated fibroblasts of the tumor stroma has the potential to predict and monitor therapeutic response to FAP-targeted CAR T-cell therapy. See related commentary by Weber et al., p. 5241.

Constipation Misperception: Could It Be Familial Adenomatosis Polyposis?

Colorectal cancer is the second leading cause of cancer deaths in the United States. Familial adenomatosis polyposis (FAP) is a rare cause of colorectal cancer. The United States Preventive Services Task Force (USPSTF) recommends screening for colorectal cancer in average-risk, asymptomatic adults aged 50 to 75 years. While age is the most important risk factor, we need to consider the family history of colorectal cancer. FAP is a rare cause of colorectal cancer, leading to high morbidity and mortality if undetected and undiagnosed. It is easy to overlook the family history in a busy primary care clinic with limited patient encounter times. Clinicians mustn't forget this important piece of information as it can give leads for further patient evaluation. We present a case report of a 21-year-old male who presented to our clinic to establish primary care and with vague abdominal complaints. Still, the concerning family history of early onset colon cancer in his half-sister raised red flags and directed us to further evaluate. Further evaluation revealed our patient, in fact, had FAP.

Cribiform-morular variant of papillary thyroid carcinoma and familial adenomatous polyposis: Report of a case

Cribiform-morular thyroid carcinoma is a rare variant of papillary thyroid carcinoma. It is usually related to Familial Adenomatous Polyposis (FAP) but rarely it may be sporadic. This variant of PTC occurs in young females and it is rare in the elderly. We report a case of a 20 years old female presenting thyroid carcinoma and personal history of FAP.

Functional Amyloids Are the Rule Rather Than the Exception in Cellular Biology

Amyloids are a class of protein aggregates that have been historically characterized by their relationship with human disease. Indeed, amyloids can be the result of misfolded proteins that self-associate to form insoluble, extracellular plaques in diseased tissue. For the first 150 years of their study, the pathogen-first definition of amyloids was sufficient. However, new observations of amyloids foster an appreciation for non-pathological roles for amyloids in cellular systems. There is now evidence from all domains of life that amyloids can be non-pathogenic and functional, and that their formation can be the result of purposeful and controlled cellular processes. So-called functional amyloids fulfill an assortment of biological functions including acting as structural scaffolds, regulatory mechanisms, and storage mechanisms. The conceptual convergence of amyloids serving a functional role has been repeatedly confirmed by discoveries of additional functional amyloids. With dozens already known, and with the vigorous rate of discovery, the biology of amyloids is robustly represented by non-pathogenic amyloids.

Ex vivo resection and intestinal autotransplantation for a large mesenteric desmoid tumor secondary to familial adenomatous polyposis: A case report and literature review

RATIONALE

The mesenteric desmoid tumor requires special attention and the most demanding treatment.

PATIENT CONCERNS

Here we present a rare case of a large mesenteric desmoid tumor secondary to familial adenomatous polyposis (FAP) in a 34-year-old man accepted the ex vivo resection, and intestinal autotransplantation.

DIAGNOSES

A 34-year-old man was referred to our department with a 6-year history of intermittent hematochezia without any other discomfort after undergoing partial colectomy in February 2013, and 5 endoscopic mucosal resections of colon polyps between May 2012 and July 2015 due to pathological diagnosis of FAP. A computed tomography scan showed a huge abdominal mass with indistinct boundary at the root of the mesentery. The adjacent organs were pushed and most of the superior mesenteric artery branches were infiltrated.

INTERVENTIONS

An en bloc resection (R0 resection), and an ex vivo resection followed by intestinal autotransplantation was performed.

OUTCOMES

The patient was discharged from the hospital on the 25th day after the operation, and was regularly followed up after surgery with abdominal ultrasonography and laboratory-biochemical tests every month, and serial CT scans every 3 months which showed no evidence of tumor recurrence, thrombus, intestinal obstruction or abdominal infection so far.

LESSONS

An ex vivo resection and intestinal autotransplantation appear feasible for cases with pathological lesions involving the vessels at the root of mesentry, and represents an attractive alternative for the management of mesenteric desmoid tumors.

Chemoprevention of colorectal cancer

Colorectal cancer has become one of the most prevalent malignant diseases for both men and women. Patients with inflammatory bowel diseases or certain inherited cancer syndromes are at high risk of developing colorectal cancer and have naturally the highest need for cancer prevention. In familial adenomatous polyposis (FAP) and Lynch syndrome, most of the underlying germline mutations can be detected by DNA sequencing, and medical counselling of affected individuals involves both surveillance tests and chemopreventive measures. However, as the mechanisms leading to colorectal cancer differ in these high-risk groups, the molecular action of chemopreventive drugs needs to be adjusted to the certain pathway of carcinogenesis. In the last decades, a number of drugs have been tested, including sulindac, aspirin, celecoxib, and mesalazine, but some of them are still controversially discussed. This review summarizes the advances and current standards of colorectal cancer prevention in patients with inflammatory bowel disease, FAP and Lynch syndrome.

Stop the pain: study protocol for a randomized-controlled trial

BACKGROUND

Functional abdominal pain (FAP) is not only a highly prevalent disease but also poses a considerable burden on children and their families. Untreated, FAP is highly persistent until adulthood, also leading to an increased risk of psychiatric disorders. Intervention studies underscore the efficacy of cognitive behavioral treatment approaches but are limited in terms of sample size, long-term follow-up data, controls and inclusion of psychosocial outcome data.

METHODS/DESIGN

In a multicenter randomized controlled trial, 112 children aged 7 to 12 years who fulfill the Rome III criteria for FAP will be allocated to an established cognitive behavioral training program for children with FAP (n = 56) or to an active control group (focusing on age-appropriate information delivery; n = 56). Randomization occurs centrally, blockwise and is stratified by center. This study is performed in five pediatric gastroenterology outpatient departments. Observer-blind assessments of outcome variables take place four times: pre-, post-, 3- and 12-months post-treatment. Primary outcome is the course of pain intensity and frequency. Secondary endpoints are health-related quality of life, pain-related coping and cognitions, as well as self-efficacy.

DISCUSSION

This confirmatory randomized controlled clinical trial evaluates the efficacy of a cognitive behavioral intervention for children with FAP. By applying an active control group, time and attention processes can be controlled, and long-term follow-up data over the course of one year can be explored.

TRIAL REGISTRATION

DRKS00005038 (date: 25 July 2013); NCT02030392 (date: 7 January 2014).

Expression of Fap amyloids in Pseudomonas aeruginosa, P. fluorescens, and P. putida results in aggregation and increased biofilm formation

The fap operon, encoding functional amyloids in Pseudomonas (Fap), is present in most pseudomonads, but so far the expression and importance for biofilm formation has only been investigated for P. fluorescens strain UK4. In this study, we demonstrate the capacity of P. aeruginosa PAO1, P. fluorescens Pf-5, and P. putida F1 to express Fap fibrils, and investigated the effect of Fap expression on aggregation and biofilm formation. The fap operon in all three Pseudomonas species conferred the ability to express Fap fibrils as shown using a recombinant approach. This Fap overexpression consistently resulted in highly aggregative phenotypes and in increased biofilm formation. Detailed biophysical investigations of purified fibrils confirmed FapC as the main fibril monomer and supported the role of FapB as a minor, nucleating constituent as also indicated by bioinformatic analysis. Bioinformatics analysis suggested FapF and FapD as a potential β-barrel membrane pore and protease, respectively. Manipulation of the fap operon showed that FapA affects monomer composition of the final amyloid fibril, and that FapB is an amyloid protein, probably a nucleator for FapC polymerization. Our study highlights the fap operon as a molecular machine for functional amyloid formation.

CLINICAL MANAGEMENT OF FAMILIES WITH HEREDITARY COLORECTAL CANCER SYNDROMES

Hereditary colorectal cancer syndromes can be associated with a lifetime risk of CRC of >70% in the absence of specialized surveillance. Diagnosing a genetic predisposition to cancer allows clinicians to tailor cancer prevention strategies for patients and families at highest risk. Once a genetic syndrome has been identified in a family, communication with family members, timely implementation of screening tests and/or surgeries, and psychosocial support are all instrumental for effective cancer prevention.Molecular screening of tumors, computerized risk assessment models, and genetic testing can help clinicians identify individuals at risk for hereditary cancer syndromes. This review discusses some of the complexities involved in the diagnosis and management of families with hereditary CRC syndromes and provides strategies for coordinating clinical care.

Impact of gene patents and licensing practices on access to genetic testing for inherited susceptibility to cancer: comparing breast and ovarian cancers with colon cancers

Genetic testing for inherited susceptibility to breast and ovarian cancer can be compared with similar testing for colorectal cancer as a "natural experiment." Inherited susceptibility accounts for a similar fraction of both cancers and genetic testing results guide decisions about options for prophylactic surgery in both sets of conditions. One major difference is that in the United States, Myriad Genetics is the sole provider of genetic testing, because it has sole control of relevant patents for BRCA1 and BRCA2 genes, whereas genetic testing for familial colorectal cancer is available from multiple laboratories. Colorectal cancer-associated genes are also patented, but they have been nonexclusively licensed. Prices for BRCA1 and 2 testing do not reflect an obvious price premium attributable to exclusive patent rights compared with colorectal cancer testing, and indeed, Myriad's per unit costs are somewhat lower for BRCA1/2 testing than testing for colorectal cancer susceptibility. Myriad has not enforced patents against basic research and negotiated a Memorandum of Understanding with the National Cancer Institute in 1999 for institutional BRCA testing in clinical research. The main impact of patenting and licensing in BRCA compared with colorectal cancer is the business model of genetic testing, with a sole provider for BRCA and multiple laboratories for colorectal cancer genetic testing. Myriad's sole-provider model has not worked in jurisdictions outside the United States, largely because of differences in breadth of patent protection, responses of government health services, and difficulty in patent enforcement.

Food restriction inhibits the growth of intestinal polyps in multiple intestinal neoplasia mouse

The effect of food restriction (FR) on spontaneous intestinal carcinogenesis in multiple intestinal neoplasia (Min) mice was examined. Thirty male Min mice were allotted to ad libitum feeding control and 20% FR groups from six weeks of age until the end of the 13-week experimental period. Although the total number of visible intestinal polyps in the FR group was not significantly different from the control group value, a significant decrease in large-sized polyps (>2 mm) and an increase in small-sized polyps (< or =2 mm) were observed in the distal small intestine. In this segment, the percentage of apoptotic cells counted in intestinal polyps in the FR group was significantly higher than in the control group, the percentage of proliferating cell nuclear antigen (PCNA)-positive cells not being significantly different. These results indicate that the FR may inhibit the growth of intestinal polyps in the Min mouse, and that apoptosis contributed in part to the inhibitory effect.

Epithelial stem cell repertoire in the gut: clues to the origin of cell lineages, proliferative units and cancer

Gastrointestinal stem cells are shown to be pluripotential and to give rise to all cell lineages in the epithelium. After damage, gut stem cells produce reparative cell lineages that produce a wide range of peptides with important actions on cell proliferation and migration, and promote regeneration and healing. Increase in stem cell number is considered to induce crypt fission, and lead to increases in the number of crypts, even in the adult; it is also the mode of spread of mutated clones in the colorectal mucosa. Stem cell repertoire is defined by both intrinsic programming of the stem cell itself, but signalling from the mesenchyme is also vitally important for defining both stem cell progeny and proliferation. Carcinogenesis in the colon occurs through sequential mutations, possibly occurring in a single cell. A case is made for this being the stem cell, but recent studies indicate that several stem cells may need to be so involved, since early lesions appear to be polyclonal in derivation.

Familial adenomatous polyposis is associated with a marked decrease in alkaline sphingomyelinase activity: a key factor to the unrestrained cell proliferation?

The hydrolysis of sphingomyelin generates key molecules regulating cell growth and inducing apoptosis. Data from animal cancer models support an inhibitory role for this pathway in the malignant transformation of the colonic mucosa. In the intestinal tract, a sphingomyelinase with an optimum alkaline pH has been identified. We recently found that the activity of alkaline sphingomyelinase is significantly decreased in colorectal adenocarcinomas, indicating a potential anticarcinogenic role of this enzyme. To further examine whether the reduction of sphingomyelinase is present already in the premalignant state of neoplastic transformation, we measured sphingomyelinase activities in patients with familial adenomatous polyposis (FAP) and in sporadic colorectal tubulovillous adenomas. Tissue samples were taken from adenomas and surrounding macroscopically normal mucosa from 11 FAP patients operated with ileorectal anastomosis, from three FAP patients with intact colon, from 13 patients with sporadic colorectal adenomas and from 12 controls. Activities of acid, neutral and alkaline sphingomyelinase were measured together with alkaline phosphatase. In FAP adenoma tissue, alkaline sphingomyelinase activity was reduced by 90% compared to controls (P < 0.0001), acid sphingomyelinase by 66% (P < 0.01) and neutral sphingomyelinase by 54% (P < 0.05). Similar reductions were found in the surrounding mucosa. In sporadic adenoma tissue, only alkaline sphingomyelinase was reduced significantly, by 57% (P < 0.05). Alkaline phosphatase was not changed in FAP adenomas, but decreased in the sporadic adenomas. We conclude that the markedly reduced levels of alkaline sphingomyelinase activities in FAP adenomas and in the surrounding mucosa may be a pathogenic factor that can lead to unrestrained cell proliferation and neoplastic transformation.

K-ras2 activation and genome instability increase proliferation and size of FAP adenomas

The possible role of K-ras2 mutations and aneuploidy toward increase of proliferation and adenoma size in Familial Adenomatous Polyposis (FAP) adenomas is not known. The present study addresses these issues by investigating 147 colorectal adenomas obtained from four FAP patients. The majority of adenomas had size lower than or equal to 10 mm (86%), low grade dysplasia (63%), and were preferentially located in the right colon (60%). Normal mucosa samples were obtained from 19 healthy donors. Three synchronous adenocarcinomas were also investigated. K-ras2 mutation spectrum was analysed by PCR and Sequence Specific Oligonucleotide (SSO) hybridization, while flow cytometry (FCM) was used for evaluating degree of DNA ploidy and S-phase fraction. Overall, incidences of K-ras2 mutations, DNA aneuploidy and high S-phase values (>7.2%) were 6.6%, 5.4% and 10.5%, respectively. In particular, among the adenomas with size lower than 5 mm, K-ras2 mutation and DNA aneuploidy frequencies were only slightly above 1%. Statistically significant correlations were found between K-ras2 and size, DNA ploidy and size and K-ras2 and S-phase (p < 0.001). In particular, among the wild type K-ras2 adenomas, high S-phase values were detected in 8% of the cases versus 57% among the K-ras2 mutated adenomas (p = 0.0005). The present series of FAP adenomas indicates that K-ras2 activation and gross genomic changes play a role toward a proliferative gain and tumour growth in size.

Significance of apoptosis in the process of tumorigenesis in colorectal mucosa and adenomas in FAP patients

The relation between proliferation and apoptosis was studied in colorectal mucosal biopsies (N = 41), tubular adenomas (TA) (N = 104) and tubulovillous adenomas (TVA) (N = 34) from 37 FAP patients. Proliferative activity was determined by cell cycle distribution analysis. In addition, transcriptional capacity was determined by chromatin in situ testing. For both, DNA flow cytometry was used. Cycling cells were identified by immunohistochemical staining with monoclonal antibody Ki67. The existence of subdiploid apoptotic cells was derived from DNA and/or DNA/protein patterns. In a follow-up group, the mucosa is characterised by a balance between proliferation (S % + G2M % = 19) and apoptotic cells (% = 17). The percentage of Ki67 positive cells (16%) corresponds to the percentages mentioned above. In TA, the amount of apoptotic cells remains unaltered, in TVA it decreases to 8%. At the same time, the percentage of Ki67 positive cells increases significantly in both TA and TVA (39%, 42%). With patients who underwent surgery due to clinical signs without histological evidence for malignancy, apoptotic cells in TA continue to decrease significantly (9%), without any changes in cycling cells. Only in the carcinoma-bearing bowel, cycling cells increase to 52%. Here, the percentage of apoptotic cells in TVA reaches the lowest level (5%). A connection between proliferation and apoptosis was observed in mucosa and TVA. The process of tumorigenesis is characterised by a stepwise increase in resistance to apoptosis followed by an increase in cycling cells.