A recurrence-predictive model based on eight genes and tumor mutational burden/microsatellite instability status in Stage II/III colorectal cancer.

BACKGROUND: Although adjuvant chemotherapy (ACT) is widely used to treat patients with Stage II/III colorectal cancer (CRC), administering ACT to specific patients remains a challenge. The decision to ACT requires an accurate assessment of recurrence risk and absolute treatment benefit. However, the traditional TNM staging system does not accurately assess a patient's individual risk of recurrence. METHODS: To identify recurrence risk-related genetic factors for Stage II/III CRC patients after radical surgery, we conducted an analysis of whole-exome sequencing of 47 patients with Stage II/III CRC who underwent radical surgery at five institutions. Patients were grouped into non-recurrence group (NR, n = 24, recurrence-free survival [RFS] > 5 years) and recurrence group (R, n = 23, RFS <2 years). The TCGA-COAD/READ cohort was employed as the validation dataset. RESULTS: A recurrence-predictive model (G8plus score) based on eight gene (CUL9, PCDHA12, HECTD3, DCX, SMARCA2, FAM193A, AATK, and SORCS2) mutations and tumor mutation burden/microsatellite instability (TMB/MSI) status was constructed, with 97.87% accuracy in our data and 100% negative predictive value in the TCGA-COAD/READ cohort. For the TCGA-COAD/READ cohort, the G8plus-high group had better RFS (HR = 0.22, p = 0.024); the G8plus-high tumors had significantly more infiltrated immune cell types, higher tertiary lymphoid structure signature scores, and higher immunological signature scores. The G8plus score was also a predict biomarker for immunotherapeutic in advanced CRC in the PUCH cohort. CONCLUSIONS: In conclusion, the G8plus score is a powerful biomarker for predicting the risk of recurrence in patients with stage II/III CRC. It can be used to stratify patients who benefit from ACT and immunotherapy.

Perineal defect reconstruction after surgery for advanced or locally recurrent rectal cancer involving organ resection: Multiple flaps combined with lining repair.

AIM: The aim of this study was to investigate the efficacy of multiple perineal perforator flaps in repairing deep perineal defects after pelvic exenteration for locally advanced or recurrent rectal cancer. METHOD: We investigated the outcomes of eight patients whose repairs involved a novel method of using an internal pudendal artery perforator (IPAP) flap combined with an inferior gluteal artery perforator (IGAP) flap. RESULTS: There were four male and four female patients with a mean age of 56 years (36-72 years). Bilateral IPAP flaps combined with bilateral IGAP flaps were used in five patients, unilateral IPAP flaps combined with bilateral IGAP flaps were used in two patients and bilateral IPAP flaps were used in one patient. There were no functional limitations in daily activities during the 6-month follow-up period. CONCLUSION: Our study showed that using multiple perineal perforator flaps combined with lining repair is feasible for repairing deep perineal defects in patients who have undergone rectal cancer surgery that includes pelvic exenteration.

E2F3 accelerates the stemness of colon cancer cells by activating the STAT3 pathway.

Introduction: Colon cancer is one of the most prevalent malignancies and causes of cancer-related deaths worldwide. Thus, further research is required to explicate the latent molecular mechanisms and look for novel biomarkers. E2F3 has been confirmed to be an oncogene in a variety of cancers. However, the particular regulation of E2F3 in colon cancer needs further investigation. Methods: The self-renewal ability was detected through a sphere formation assay. The tumorigenic ability was measured through nude mice in vivo assay. The protein expression of genes was examined through a Western blot. The expression of E2F3 in tumor tissues was detected through an IHC assay. The resistance to cisplatin was assessed through the CCK-8 assay. The cell migration and invasion abilities were measured after upregulating or suppressing E2F3 through the Transwell assay. Results: Results uncovered that E2F3 was upregulated in spheroid cells. In addition, E2F3 facilitates stemness in colon cancer. Moreover, E2F3 facilitated colon cancer cell migration and invasion. Finally, it was revealed that E2F3 affected the STAT3 pathway to modulate stemness in colon cancer. E2F3 served as a promoter regulator in colon cancer, aggravating tumorigenesis and stemness in colon cancer progression through the STAT3 pathway. Conclusion: E2F3 may be a useful biomarker for anticancer treatment in colon cancer.

Breviscapine regulates the proliferation, migration, invasion, and apoptosis of colorectal cancer cells via the PI3K/AKT pathway.

Colorectal cancer (CRC) is ranked as one of the most common malignancies with a high death rate. It has been discovered that breviscapine can alter the progression and development of various cancers. Nevertheless, the function and mechanisms of breviscapine in CRC progression have not yet been described. The cell proliferation capacity of HCT116 and SW480 cells was assessed using the CCK-8 and EdU assays. Cell apoptosis was tested through flow cytometry, and cell migration and invasion were examined using the transwell assay. Moreover, protein expression was examined through a western blot. Tumor weight and volume were assessed using the nude mice in vivo assay, and the Ki-67 protein expression was verified through the IHC assay. This study discovered that an increased dose of breviscapine (0, 12.5, 25, 50, 100, 200, and 400 µM) gradually reduced cell proliferation and increased apoptosis in CRC. Additionally, breviscapine restricted the migration and invasion CRC cells. Moreover, it was revealed that breviscapine inactivated the PI3K/AKT pathway and inhibited CRC progression. Finally, an in vivo assay demonstrated that breviscapine restrained tumor growth in vivo. It affected the CRC cells' proliferation, migration, invasion, and apoptosis through the PI3K/AKT pathway. This discovery may offer new insights into CRC treatment.

Rectal cancer-derived exosomes activate the nuclear factor kappa B pathway and lung fibroblasts by delivering integrin beta-1.

Numerous studies have revealed the importance of tumor-derived exosomes in rectal cancer (RC). This study aims to explore the influence of tumor-derived exosomal integrin beta-1 (ITGB1) on lung fibroblasts in RC along with underlying mechanisms. Exosome morphology was observed using a transmission electron microscope. Protein levels of CD63, CD9, ITGB1, p-p65 and p65 were detected using Western blot. To determine ITGB1's mRNA expression, quantitative real-time polymerase chain reaction was used. Moreover, levels of interleukin (IL)-8, IL-1ß, and IL-6 in cell culture supernatant were measured via commercial ELISA kits. ITGB1 expression was increased in exosomes from RC cells. The ratio of p-p65/p65 as well as levels of interleukins in lung fibroblasts was raised by exosomes derived from RC cells, while was reduced after down-regulation of exosomal ITGB1. The increased ratio of p-p65/p65 as well as levels of pro-inflammatory cytokines caused by exosomes from RC cells was reversed by the addition of nuclear factor kappa B (NF-κB) inhibitor. We concluded that the knockdown of RC cells-derived exosomal ITGB1 repressed activation of lung fibroblasts and the NF-κB pathway in vitro.

Development and validation of postoperative circulating tumor DNA combined with clinicopathological risk factors for recurrence prediction in patients with stage I-III colorectal cancer.

BACKGROUND: Circulating tumor DNA (ctDNA) detection following curative-intent surgery could directly reflect the presence of minimal residual disease, the ultimate cause of clinical recurrence. However, ctDNA is not postoperatively detected in ≥ 50% of patients with stage I-III colorectal cancer (CRC) who ultimately recur. Herein we sought to improve recurrence risk prediction by combining ctDNA with clinicopathological risk factors in stage I-III CRC. METHODS: Two independent cohorts, both consisting of early-stage CRC patients who underwent curative surgery, were included: (i) the discovery cohort (N = 124) with tumor tissues and postoperative plasmas for ctDNA determination; and (ii) the external validation cohort (N = 125) with available ctDNA results. In the discovery cohort, somatic variations in tumor tissues and plasmas were determined via a 733-gene and 127-gene next-generation sequencing panel, respectively. RESULTS: In the discovery cohort, 17 of 108 (15.7%) patients had detectable ctDNA. ctDNA-positive patients had a significantly high recurrence rate (76.5% vs. 16.5%, P < 0.001) and short recurrence-free survival (RFS; P < 0.001) versus ctDNA-negative patients. In addition to ctDNA status, the univariate Cox model identified pathologic stage, lymphovascular invasion, nerve invasion, and preoperative carcinoembryonic antigen level associated with RFS. We combined the ctDNA and clinicopathological risk factors (CTCP) to construct a model for recurrence prediction. A significantly higher recurrence rate (64.7% vs. 8.1%, P < 0.001) and worse RFS (P < 0.001) were seen in the high-risk patients classified by the CTCP model versus those in the low-risk patients. Receiver operating characteristic analysis demonstrated that the CTCP model outperformed ctDNA alone at recurrence prediction, which increased the sensitivity of 2 year RFS from 49.6% by ctDNA alone to 87.5%. Harrell's concordance index, calibration curve, and decision curve analysis also suggested that the CTCP model had good discrimination, consistency, and clinical utility. These results were reproduced in the validation cohort. CONCLUSION: Combining postoperative ctDNA and clinical risk may better predict recurrence than ctDNA alone for developing a personalized postoperative management strategy for CRC.

Surgical treatment of massive stoma site tumors after a curative operation for rectal cancer.

OBJECTIVE: This study aimed to evaluate the clinical and oncological outcomes of selected rectal cancer patients with massive stoma site tumors who underwent radical resection and reconstruction. METHODS: We reviewed 8 cases of massive stoma site tumors in patients who had permanent gastrointestinal stoma in the abdominal wall following radical resection of rectal cancer between March 2013 and May 2018 at the Peking University Cancer Hospital and Peking University Shougang Hospital. RESULTS: There were seven males and one female patient, with a median age of 50.6 years. The average time between the initial surgery and the development of a malignant tumor at the stoma site was 5 years (range, 0.5-14 years). The average diameter of the stoma site tumors was 8.1 cm, and the diameter of the largest tumor was 12 cm. After tumor resection, the area of the largest abdominal wall defect was about 15 × 14 cm2. Abdominal wall repair included the use of a tensor fasciae latae muscle flap, local fasciocutaneous rotational flap, and pedicled anterolateral thigh flap. No patient died in the 30 days following surgery. The longest follow-up period was 81 months, and 5 patients died. CONCLUSIONS: Multidisciplinary clinical management fosters positive outcomes in treating massive stoma site tumors. Local R0 resection and abdominal wall reconstruction are safe and feasible, and function to removes local disease, allowing patients to live a higher quality of life.

Functional Passenger-Strand miRNAs in Exosomes Derived from Human Colon Cancer Cells and Their Heterogeneous Paracrine Effects.

Exosome-mediated microRNAs (miRNAs) are closely related to the occurrence, development, invasion, metastasis, therapeutic resistance, diagnosis and treatment of malignant tumors. Guide-strand miRNA and passenger-strand miRNA (miRNA*) exist in miRNA processing, but the function of passenger-strand miRNA is often overlooked. In this study, we attempted to identify functional miRNA*s in exosomes derived from human colon cancer SW620 cells. miRNA expression profiles of human normal colonic epithelial cells NCM460 and colon cancer cells SW620 were compared by high-throughput sequencing. According to the sequencing results, we defined two sets of differentially expressed miRNAs: "high in exosome and high in cell" (HEHC) and "high in exosome but low in cell" (HELC). As passenger-strand miRNAs, miR-2277-3p and miR-26b-3p, which belong to different sets, have diametrically opposite functions. MiR-2277-3p promotes proliferation, migration, and invasion of SW620 cells by targeting NUPR1L, while miR-26b-3p exerts an inhibitory effect by targeting PFDN1. Using exosomes as transport vectors, the effect of exosomes rich in miR-2277-3p on cells is consistent with the effect of liposome-transfected overexpressed miR-2277-3p, resulting in a cancer-promoting effect. However, exosomes rich in miR-26b-3p did not have a tumor suppressor effect. Further analysis revealed that exosomes rich in miR-2277-3p also had a high abundance of integrin ß4. Altering the abundance of integrin ß4 in exosomes changes the ability of exosomes to be taken up by cells, thereby altering the paracrine effects of exosomes. In summary, we revealed the fact that a large number of passenger-strand miRNAs exist in exosomes of colon cancer cells, these miRNAs are preliminarily categorized into two sets, and miR-2277-3p and miR-26b-3p, as representatives of each set, showed opposite functions. In addition, we revealed that integrin ß4 is a marker of exosome heterogeneity in colon cancer cells, which directly correlates with the ability of exosomes to be uptaken by cells of the same kind, thus regulating the paracrine effect of exosomes.

An enrichment model using regular health examination data for early detection of colorectal cancer.

OBJECTIVE: Challenges remain in current practices of colorectal cancer (CRC) screening, such as low compliance, low specificities and expensive cost. This study aimed to identify high-risk groups for CRC from the general population using regular health examination data. METHODS: The study population consist of more than 7,000 CRC cases and more than 140,000 controls. Using regular health examination data, a model detecting CRC cases was derived by the classification and regression trees (CART) algorithm. Receiver operating characteristic (ROC) curve was applied to evaluate the performance of models. The robustness and generalization of the CART model were validated by independent datasets. In addition, the effectiveness of CART-based screening was compared with stool-based screening. RESULTS: After data quality control, 4,647 CRC cases and 133,898 controls free of colorectal neoplasms were used for downstream analysis. The final CART model based on four biomarkers (age, albumin, hematocrit and percent lymphocytes) was constructed. In the test set, the area under ROC curve (AUC) of the CART model was 0.88 [95% confidence interval (95% CI), 0.87-0.90] for detecting CRC. At the cutoff yielding 99.0% specificity, this model's sensitivity was 62.2% (95% CI, 58.1%-66.2%), thereby achieving a 63-fold enrichment of CRC cases. We validated the robustness of the method across subsets of test set with diverse CRC incidences, aging rates, genders ratio, distributions of tumor stages and locations, and data sources. Importantly, CART-based screening had the higher positive predictive value (1.6%) than fecal immunochemical test (0.3%). CONCLUSIONS: As an alternative approach for the early detection of CRC, this study provides a low-cost method using regular health examination data to identify high-risk individuals for CRC for further examinations. The approach can promote early detection of CRC especially in developing countries such as China, where annual health examination is popular but regular CRC-specific screening is rare.

An oncogenic gene, SNRPA1, regulates PIK3R1, VEGFC, MKI67, CDK1 and other genes in colorectal cancer.

PURPOSE: Colorectal cancer (CRC) caused more than 65,000 mortalities worldwide per year. It is a result of one or a combination of chromosomal instability, CpG island methylator phenotype, and microsatellite instability. SNRPA1 (small nuclear ribonucleoprotein polypeptide A) is a subunit of spliceosome complex that is involved in the RNA processing. Overexpression of SNRPA1 has been implicated in a variety of cancers including CRC. Besides from its role in mediating the RNA processing, the other aspects regarding its function in the progression of colorectal cancer have not been revealed. METHODS: Herein, we combined regular gene overexpression or knock down in vitro and in vivo and microarray gene profiling analysis to decipher the unknow regulatory role of SNRPA1 in CRC. RESULTS: We found SNRPA1 widely expression in many representative CRC cell lines. Knocking down expression of SNRPA1 by shRNA lentivirus inhibited the cell proliferation in vitro and impaired tumor formation from implanted CRC cells transduced with SNRPA1 silencing shRNA lentivirus in nude mice. It also promoted the cell apoptosis by upregulating the caspase 3/7 activity. Additional microarray gene profiling analysis uncovered the gene interaction network of SNRPA1, special focus was placed on its association with tumor suppressor or oncogenes. CONCLUSIONS: According to the results of gene interaction network as well as qRT-PCR verification, it revealed that SNPRA1 regulates PIK3R1, VEGFC, MKI67, CDK1 in CRC. These novel findings identified new roles played by SNRPA1 in the progression of CRC and it may become a potential therapeutic target in the treatment of CRC.

[Postoperative complications after rectal cancer surgery and management].

Although neoadjuvant treatment such as radiotherapy, even chemoradiotherapy has already widely used in middle-low rectal cancer, surgery remains the mainstay of therapy for patients with rectal cancer. Because neoadjuvant chemoradiotherapy combined with surgery was adopted for the locally advanced rectal cancer as a standard treatment based on guidelines, postoperative complications of rectal cancer surgery caused surgeons attention and concern gradually. Some severe complications should seriously affect patient's quality of life, even patient's survival. Therefore, surgeons should be fully aware of the severity of complications, and try to avoid the occurrence of complications. Thoroughly knowing the significance of comprehensive treatment in rectal cancer, meanwhile, realizing associated complications following rectal cancer operation, and choosing reasonable, standard, effective and economic management will result in obvious increase of therapeutic level in rectal cancer surgery in China. Through the literature review combined with our clinical experience, this paper analyzes the reasons of seven associated complications, including intra-operational bleeding, bladder damage, postoperative anastomotic leakage, rectovaginal fistula, postoperative bleeding, postoperative ileus, postoperative anastomotic stenosis and anterior resection syndrome, and shares the managements in order to provide more references to surgeons.