Patient-Derived Colorectal Cancer Organoids Upregulate Revival Stem Cell Marker Genes following Chemotherapeutic Treatment

Colorectal cancer stem cells have been proposed to drive disease progression, tumour recurrence and chemoresistance. However, studies ablating leucine rich repeat containing G protein-coupled receptor 5 (LGR5)-positive stem cells have shown that they are rapidly replenished in primary tumours. Following injury in normal tissue, LGR5+ stem cells are replaced by a newly defined, transient population of revival stem cells. We investigated whether markers of the revival stem cell population are present in colorectal tumours and how this signature relates to chemoresistance. We examined the expression of different stem cell markers in a cohort of patient-derived colorectal cancer organoids and correlated expression with sensitivity to 5-fluorouracil (5-FU) treatment. Our findings revealed that there was inter-tumour variability in the expression of stem cell markers. Clusterin (CLU), a marker of the revival stem cell population, was significantly enriched following 5-FU treatment and expression correlated with the level of drug resistance. Patient outcome data revealed that CLU expression is associated with both lower patient survival and an increase in disease recurrence. This suggests that CLU is a marker of drug resistance and may identify cells that drive colorectal cancer progression.

Modeling colorectal cancer: A bio-resource of 50 patient-derived organoid lines

BACKGROUND AND AIM

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide. To improve outcomes for these patients, we need to develop new treatment strategies. Personalized cancer medicine, where patients are treated based on the characteristics of their own tumor, has gained significant interest for its promise to improve outcomes and reduce unnecessary side effects. The purpose of this study was to examine the potential utility of patient-derived colorectal cancer organoids (PDCOs) in a personalized cancer medicine setting.

METHODS

Patient-derived colorectal cancer organoids were derived from tissue obtained from treatment-naïve patients undergoing surgical resection for the treatment of CRC. We examined the recapitulation of key histopathological, molecular, and phenotypic characteristics of the primary tumor.

RESULTS

We created a bio-resource of PDCOs from primary and metastatic CRCs. Key histopathological features were retained in PDCOs when compared with the primary tumor. Additionally, a cohort of 12 PDCOs, and their corresponding primary tumors and normal sample, were characterized through whole exome sequencing and somatic variant calling. These PDCOs exhibited a high level of concordance in key driver mutations when compared with the primary tumor.

CONCLUSIONS

Patient-derived colorectal cancer organoids recapitulate characteristics of the tissue from which they are derived and are a powerful tool for cancer research. Further research will determine their utility for predicting patient outcomes in a personalized cancer medicine setting.

Sustained Clinical Response to Immunotherapy Followed by BET Inhibitor in a Patient with Unresectable Sinonasal NUT Carcinoma

NUT carcinomas (NCs) are a group of rare tumors that can occur anywhere in the body and are defined by the fusion of the nuclear protein in testis (NUTM1) resulting in increased transcription of proto-oncogenes. NCs have a poor prognosis that varies according to the site of origin with an urgent need to develop new treatment strategies. Case reports on immunotherapy in pulmonary NC have been published, and bromodomain and extraterminal (BET) inhibitors have shown activity in NC in phase I/II trials. We present the case of a 27-year-old woman with an unresectable sinonasal NC who had a sustained clinical response to both immunotherapy and BET inhibitor therapy. This is the first reported case of immunotherapy in sinonasal NC, and it highlights the different responses to a range of treatments including BET inhibitor therapy. This case supports the theory that NCs arising from different primary sites have differing prognoses.

β-lactam-associated eosinophilic colitis

A 42-year-old man with a history of childhood asthma presented with a 2-week history of watery diarrhoea and marked peripheral eosinophilia in the setting of recent use of cephalexin. His colonoscopy revealed patchy colitis. Biopsies were consistent with eosinophilic colitis. Two months later he received a course of amoxicillin resulting in recurrence of peripheral eosinophilia. Given the time-frame of β-lactam administration to symptom onset and elimination of all other precipitating causes, he was diagnosed with β-lactam-associated eosinophilic colitis. The patient's symptoms resolved and peripheral eosinophil count decreased with no specific treatment. Eosinophilic colitis is a rare heterogeneous condition, the pathogenesis of which is likely to be an interplay between environmental and genetic factors. It can be secondary to a helminthic infection or a drug reaction and has been associated with ulcerative colitis. If secondary causes of eosinophilic colitis have been excluded, the mainstay of treatment is with corticosteroids.

Acute scrotal ulcers in typhoid Fever: case report and literature review

Background. In developed countries, typhoid fever is a travel-associated disease that is often overlooked. However, as standard blood and stool culture methods have relatively low sensitivity, diagnosis depends heavily on clinical signs and symptoms and on a high level of suspicion.

Methods. Reported here is the case of an 18-year-old male who presented with fever and acute scrotal ulcers and whose blood cultures were positive for Salmonella enterica serotype Typhi. A review of genital ulcers associated with typhoid fever in the literature is discussed.

Conclusion. This report suggests that typhoid fever is a differential diagnosis of acute genital ulcers.