Preoperative Quality of Life and Mental Health Can Predict Postoperative Outcomes and Quality of Life after Colorectal Cancer Surgery.

Background and Objectives: It remains unclear which domains of preoperative health-related quality of life (HRQOL) and mental health are predictive of postoperative clinical and patient-reported outcomes in colorectal cancer (CRC) patients. Materials and Methods: A prospective cohort of 78 CRC patients undergoing elective curative surgery was recruited. The EORTC QLQ-C30 and HADS questionnaires were administered preoperatively and one month after surgery. Results: Preoperative cognitive functioning scores (95% CI 0.131-1.158, p = 0.015) and low anterior resection (95% CI 14.861-63.260, p = 0.002) independently predicted poorer 1-month postoperative global QOL. When postoperative complications were represented using the comprehensive complication index (CCI), poorer preoperative physical function scores were associated with higher CCI scores (B = -0.277, p = 0.014). Preoperative social function score (OR = 0.925, 95% CI 0.87 to 0.99; p = 0.019) was an independent predictor for 30-day readmission, while physical functioning score (OR = -0.620, 95% CI -1.073--0.167, p = 0.008) was inversely related to the length of hospitalization. The overall regressions for 1-month postoperative global QOL (R2: 0.546, F: 1.961, p = 0.023) and 30-day readmission (R2: 0.322, χ2: 13.129, p < 0.001) were statistically significant. Conclusions: Various QLQ-C30 domains were found to be predictive of postoperative outcomes, including complications, readmission, and length of hospitalization. Preoperative cognitive dysfunction and low AR were independent predictors of poorer postoperative global QOL. Future research should seek to examine the efficacy of targeting specific baseline QOL domains in improving clinical as well as patient-reported outcomes after CRC surgery.

Domain-specific p53 mutants activate EGFR by distinct mechanisms exposing tissue-independent therapeutic vulnerabilities.

Mis-sense mutations affecting TP53 promote carcinogenesis both by inactivating tumor suppression, and by conferring pro-carcinogenic activities. We report here that p53 DNA-binding domain (DBD) and transactivation domain (TAD) mis-sense mutants unexpectedly activate pro-carcinogenic epidermal growth factor receptor (EGFR) signaling via distinct, previously unrecognized molecular mechanisms. DBD- and TAD-specific TP53 mutants exhibited different cellular localization and induced distinct gene expression profiles. In multiple tissues, EGFR is stabilized by TAD and DBD mutants in the cytosolic and nuclear compartments respectively. TAD mutants promote EGFR-mediated signaling by enhancing EGFR interaction with AKT via DDX31 in the cytosol. Conversely, DBD mutants maintain EGFR activity in the nucleus, by blocking EGFR interaction with the phosphatase SHP1, triggering c-Myc and Cyclin D1 upregulation. Our findings suggest that p53 mutants carrying gain-of-function, mis-sense mutations affecting two different domains form new protein complexes that promote carcinogenesis by enhancing EGFR signaling via distinctive mechanisms, exposing clinically relevant therapeutic vulnerabilities.

Pan-cancer pervasive upregulation of 3' UTR splicing drives tumourigenesis.

Most mammalian genes generate messenger RNAs with variable untranslated regions (UTRs) that are important post-transcriptional regulators. In cancer, shortening at 3' UTR ends via alternative polyadenylation can activate oncogenes. However, internal 3' UTR splicing remains poorly understood as splicing studies have traditionally focused on protein-coding alterations. Here we systematically map the pan-cancer landscape of 3' UTR splicing and present this in SpUR ( http://www.cbrc.kaust.edu.sa/spur/home/ ). 3' UTR splicing is widespread, upregulated in cancers, correlated with poor prognosis and more prevalent in oncogenes. We show that antisense oligonucleotide-mediated inhibition of 3' UTR splicing efficiently reduces oncogene expression and impedes tumour progression. Notably, CTNNB1 3' UTR splicing is the most consistently dysregulated event across cancers. We validate its upregulation in hepatocellular carcinoma and colon adenocarcinoma, and show that the spliced 3' UTR variant is the predominant contributor to its oncogenic functions. Overall, our study highlights the importance of 3' UTR splicing in cancer and may launch new avenues for RNA-based anti-cancer therapeutics.

Global analysis of RNA-binding proteins identifies a positive feedback loop between LARP1 and MYC that promotes tumorigenesis.

In addition to genomic alterations, aberrant changes in post-transcriptional regulation can modify gene function and drive cancer development. RNA-binding proteins (RBPs) are a large class of post-transcriptional regulators that have been increasingly implicated in carcinogenesis. By integrating multi-omics data, we identify LARP1 as one of the most upregulated RBPs in colorectal cancer (CRC) and demonstrate its oncogenic properties. We perform LARP1:RNA interactome profiling and unveil a previously unexplored role for LARP1 in targeting the 3'UTR of oncogenes in CRC. Notably, we identify the proto-oncogenic transcription factor MYC as a key LARP1-regulated target. Our data show that LARP1 positively modulates MYC expression by associating with its 3'UTR. In addition, antisense oligonucleotide-mediated blocking of the interaction between LARP1 and the MYC 3'UTR reduces MYC expression and in vitro CRC growth. Furthermore, a systematic analysis of LARP1:protein interactions reveals IGF2BP3 and YBX1 as LARP1-interacting proteins that also regulate MYC expression and CRC development. Finally, we demonstrate that MYC reciprocally modulates LARP1 expression by targeting its enhancer. In summary, our data reveal a critical, previously uncharacterized role of LARP1 in promoting CRC tumorigenesis, validate its direct regulation of the proto-oncogene MYC and delineate a model of the positive feedback loop between MYC and LARP1 that promotes CRC growth and development.

Side-to-side versus end-to-side ileocolic anastomosis in right-sided colectomies: A cohort control study.

Aims: The three main types of anastomotic configurations following colorectal resection are Side-to-Side Anastomosis (S-S), End-to-Side Anastomosis (E-S) and End-to-End Anastomosis (E-E). This study aims to present results from a local cohort supplemented by a systematic review with meta-analysis of existing literature to compare the post-operative outcomes between E-S and S-S. Methods: A cohort study of patients who underwent right colectomy with E-S or S-S anastomosis, was conducted at the National University Hospital Singapore. Electronic databases Embase and Medline were systematically searched from inception to 21 August 2020, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Studies were included if they compared post-operative outcomes between E-S and S-S. Results: In the cohort study, 40 underwent E-S and 154 underwent S-S. Both post-operative ileus (12.5% vs. 29.2%, P = 0.041) and length of hospital stay (9.35 days vs. 14.04 days, P = 0.024) favoured E-S, but anastomotic bleed favoured S-S (15.0% vs. 3.2%, P = 0.004). Five studies were included in the meta-analysis with 860 E-S and 1126 S-S patients. Similarly, post-operative ileus (odds ratio [OR] =0.302; 95% confidence interval [CI]: 0.122-0.747; P = 0.010) and length of hospital stay (mean differences = ‒1.54 days; CI: ‒3.00 to ‒0.076 days; P = 0.039) favoured E-S. Additional sensitivity analysis including only stapled anastomosis showed a lower rate of anastomotic leak in E-S patients (OR = 0.185; 95% CI: 0.054-0.627; P = 0.007). Conclusions: This is the first systematic review to show that the E-S technique produces superior post-operative outcomes after right colectomy compared to S-S. However, the choice of anastomosis was largely surgeon dependent, but surgeon factors were not reported.

MiR-138 is a potent regulator of the heterogenous MYC transcript population in cancers.

3'UTR shortening in cancer has been shown to activate oncogenes, partly through the loss of microRNA-mediated repression. This suggests that many reported microRNA-oncogene target interactions may not be present in cancer cells. One of the most well-studied oncogenes is the transcription factor MYC, which is overexpressed in more than half of all cancers. MYC overexpression is not always accompanied by underlying genetic aberrations. In this study, we demonstrate that the MYC 3'UTR is shortened in colorectal cancer (CRC). Using unbiased computational and experimental approaches, we identify and validate microRNAs that target the MYC coding region. In particular, we show that miR-138 inhibits MYC expression and suppresses tumor growth of CRC and hepatocellular carcinoma (HCC) cell lines. Critically, the intravenous administration of miR-138 significantly impedes MYC-driven tumor growth in vivo. Taken together, our results highlight the previously uncharacterized shortening of the MYC 3'UTR in cancer, and identify miR-138 as a potent regulator of the heterogenous MYC transcript population.

Early surgery after bridge-to-surgery stenting for malignant bowel obstruction is associated with better oncological outcomes.

BACKGROUND: Placement of self-expanding metal stents has been increasingly adopted as a bridge to surgery in patients presenting with obstructed left-sided colorectal cancers. The optimal bridging time has yet to be widely established, hence this retrospective study aims to determine the optimal bridging time to elective surgery post endoluminal stenting. PATIENTS AND METHODS: All patients who underwent colorectal stenting for large bowel obstruction in a single, tertiary hospital in Singapore between January 2003 and December 2017 were retrospectively identified. Patients' baseline demographics, tumour characteristics, stent-related complications, intra-operative details, post-operative complications and oncological outcomes were analysed. RESULTS: Of the 53 patients who successfully underwent colonic stenting for malignant left sided obstruction, 33.96% of patients underwent surgery within two weeks of stent placement while 66.04% of patients underwent surgery after 2 weeks of stent placement. Univariate analysis between both groups did not demonstrate significant differences in postoperative complications and stoma formation. Significant differences were observed between both groups for stent complications (38.89% vs 8.57%, p = 0.022), on-table decompression (38.89% vs 2.86%, p = 0.001) and systemic recurrence (11.11% vs 40.00%, p = 0.030). Increased bridging interval to surgery (OR 13.16, CI 1.37-126.96, p = 0.026) was a significant risk factor for systemic recurrence on multivariate analysis. CONCLUSIONS: Patients undergoing definitive surgery within 2 weeks of colonic stenting may have better oncological outcomes without compromising on postoperative outcomes. Further prospective studies are required to compare outcomes between emergency surgery and different bridging intervals.

Perforated Intestinal Tuberculosis in a Non-AIDS Immunocompromised Patient.

BACKGROUND: Intestinal tuberculosis can mimic many conditions. The incidence of intestinal tuberculosis in developed countries has risen in tandem with the increase in patients with immunocompromised states. This is a condition which needs to be considered in patients who present with symptoms and signs of bowel perforation on a background of immunosuppression in order to obtain the correct diagnosis and, consequently, the correct treatment. CASE REPORT: We report a patient with a background of sarcoidosis who had been on mycophenolate mofetil, tacrolimus, and high-dose prednisolone. He presented with abdominal pain without overt peritonitis. Initial imaging showed small locules of free air in the abdominal cavity. The patient was managed with intravenous antibiotics as upfront surgery was deemed to be high risk. However, on a repeat imaging scan 3 days later, larger locules of gas were seen within the abdominal cavity, indicating progression and non-resolution of his acute condition. The patient was brought to the operating theatre and a perforation at the ileum was found. A segment of small bowel containing the perforation was resected. Histology showed the presence of acid-fast bacilli (AFB) on Ziehl-Neelsen stain, leading to a diagnosis of intestinal tuberculosis. CONCLUSIONS: A high index of suspicion for intestinal tuberculosis is needed in patients who are on immunosuppression. Intestinal tuberculosis presenting with perforation is unlikely to lead to spontaneous resolution without operative management, and patients should be brought to the operating theatre for immediate surgery.