Spatial and single-cell colocalisation analysis reveals MDK-mediated immunosuppressive environment with regulatory T cells in colorectal carcinogenesis

BACKGROUND

Cell-cell interaction factors that facilitate the progression of adenoma to sporadic colorectal cancer (CRC) remain unclear, thereby hindering patient survival.

METHODS

We performed spatial transcriptomics on five early CRC cases, which included adenoma and carcinoma, and one advanced CRC. To elucidate cell-cell interactions within the tumour microenvironment (TME), we investigated the colocalisation network at single-cell resolution using a deep generative model for colocalisation analysis, combined with a single-cell transcriptome, and assessed the clinical significance in CRC patients.

FINDINGS

CRC cells colocalised with regulatory T cells (Tregs) at the adenoma-carcinoma interface. At early-stage carcinogenesis, cell-cell interaction inference between colocalised adenoma and cancer epithelial cells and Tregs based on the spatial distribution of single cells highlighted midkine (MDK) as a prominent signalling molecule sent from tumour epithelial cells to Tregs. Interaction between MDK-high CRC cells and SPP1+ macrophages and stromal cells proved to be the mechanism underlying immunosuppression in the TME. Additionally, we identified syndecan4 (SDC4) as a receptor for MDK associated with Treg colocalisation. Finally, clinical analysis using CRC datasets indicated that increased MDK/SDC4 levels correlated with poor overall survival in CRC patients.

INTERPRETATION

MDK is involved in the immune tolerance shown by Tregs to tumour growth. MDK-mediated formation of the TME could be a potential target for early diagnosis and treatment of CRC.

FUNDING

Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Science Research; OITA Cancer Research Foundation; AMED under Grant Number; Japan Science and Technology Agency (JST); Takeda Science Foundation; The Princess Takamatsu Cancer Research Fund.

Tumor suppressive role of the epigenetic master regulator BRD3 in colorectal cancer

Bromodomain and extraterminal domain (BET) family proteins are epigenetic master regulators of gene expression via recognition of acetylated histones and recruitment of transcription factors and co-activators to chromatin. Hence, BET family proteins have emerged as promising therapeutic targets in cancer. In this study, we examined the functional role of bromodomain containing 3 (BRD3), a BET family protein, in colorectal cancer (CRC). In vitro and vivo analyses using BRD3-knockdown or BRD3-overexpressing CRC cells showed that BRD3 suppressed tumor growth and cell cycle G1/S transition and induced p21 expression. Clinical analysis of CRC datasets from our hospital or The Cancer Genome Atlas revealed that BET family genes, including BRD3, were overexpressed in tumor tissues. In immunohistochemical analyses, BRD3 was observed mainly in the nucleus of CRC cells. According to single-cell RNA sequencing in untreated CRC tissues, BRD3 was highly expressed in malignant epithelial cells, and cell cycle checkpoint-related pathways were enriched in the epithelial cells with high BRD3 expression. Spatial transcriptomic and single-cell RNA sequencing analyses of CRC tissues showed that BRD3 expression was positively associated with high p21 expression. Furthermore, overexpression of BRD3 combined with knockdown of, a driver gene in the BRD family, showed strong inhibition of CRC cells in vitro. In conclusion, we demonstrated a novel tumor suppressive role of BRD3 that inhibits tumor growth by cell cycle inhibition in part via induction of p21 expression. BRD3 activation might be a novel therapeutic approach for CRC.

Venous Thromboembolism Following Lateral Lymph Node Dissection for Rectal Cancer

BACKGROUND/AIM

Postoperative venous thromboembolism (VTE) is a well-recognized complication that leads to morbidity and mortality. Lateral lymph node dissection (LLND) for rectal cancer is thought to potentially increase the risk of VTE due to its technical complexity. However, the relationship between LLND and VTE remains inadequately understood. The aim of this study was to elucidate the impact of LLND on the incidence of postoperative VTE.

PATIENTS AND METHODS

This is a retrospective analysis of patients who underwent rectal cancer resection between 2010 and 2018 to identify the risk factors associated with postoperative VTE. Patients were divided into two groups: those who underwent surgery with LLND (LLND+ group) and those who underwent surgery without LLND (LLND- group).

RESULTS

A total of 543 patients were enrolled in this study, and 113 patients underwent surgery for rectal cancer with LLND. VTE developed in 8 patients (1.47%), with the incidence rates being 4.42% in the LLND+ group and 0.69% in the LLND- group, respectively (p=0.012). Three of 8 patients had developed severe postoperative complications, and the other two patients needed intraoperative repair of the iliac vein during LLND procedure. Multivariate analysis identified the incidence of postoperative complications and LLND as the independent risk factors of VTE.

CONCLUSION

Patients undergoing rectal cancer surgery with LLND should be closely monitored for signs of VTE.

Laparoscopic Colorectal Cancer Surgery for Patients With Severe Chronic Heart Failure

BACKGROUND/AIM

Laparoscopic surgery with pneumoperitoneum is not usually recommended for patients with heart failure due to the potential risks associated with cardiopulmonary stress. Few studies, however, have directly examined whether a laparoscopic approach can be used safely in patients with severe chronic heart failure.

PATIENTS AND METHODS

We retrospectively evaluated the safety and feasibility of laparoscopic colorectal cancer surgery in 13 patients with severe chronic heart failure, defined as left ventricular ejection fraction <40% and/or brain natriuretic peptide >100 pg/ml (NT-proBNP >400 pg/ml). Intraoperative hemodynamics, including systolic blood pressure, diastolic blood pressure, mean blood pressure, and heart rate, were carefully monitored.

RESULTS

The median left ventricular ejection fraction value was 35% (18-62%), and the median brain natriuretic peptide value was 171.7 pg/ml (109.5-961.4 pg/ml). The time-series mean ratio of the patients' blood pressure and heart rate during surgery indicated that soon after the induction of general anesthesia, mean blood pressure was significantly decreased (p<0.05) from baseline. In all 13 cases, laparoscopic surgery was performed successfully, with no significant complications.

CONCLUSION

The present study showed that laparoscopic surgery for colorectal cancer can be performed safely in patients with severe chronic heart failure.

Metastases and treatment-resistant lineages in patient-derived cancer cells of colorectal cancer

Circulating tumor cells (CTCs) play an important role in metastasis and recurrence. However, which cells comprise the complex tumor lineages in recurrence and are key in metastasis are unknown in colorectal cancer (CRC). CRC with high expression of POU5F1 has a poor prognosis with a high incidence of liver metastatic recurrence. We aim to reveal the key cells promoting metastasis and identify treatment-resistant lineages with established EGFP-expressing organoids in two-dimensional culture (2DOs) under the POU5F1 promotor. POU5F1-expressing cells are highly present in relapsed clinical patients' blood as CTCs. Sorted POU5F1-expressing cells from 2DOs have cancer stem cell abilities and abundantly form liver metastases in vivo. Single-cell RNA sequencing of 2DOs identifies heterogeneous populations derived from POU5F1-expressing cells and the Wnt signaling pathway is enriched in POU5F1-expressing cells. Characteristic high expression of CTLA4 is observed in POU5F1-expressing cells and immunocytochemistry confirms the co-expression of POU5F1 and CTLA4. Demethylation in some CpG islands at the transcriptional start sites of POU5F1 and CTLA4 is observed. The Wnt/β-catenin pathway inhibitor, XAV939, prevents the adhesion and survival of POU5F1-expressing cells in vitro. Early administration of XAV939 also completely inhibits liver metastasis induced by POU5F1-positive cells.

Resection of anorectal fistula cancer associated with Crohn's disease after preoperative chemoradiotherapy: a case report

BACKGROUND

Anorectal fistula cancer is often diagnosed in an advanced state, and radical resection is difficult when invasion of the pelvic wall is observed. In addition, there is currently no clear evidence for perioperative treatment of locally advanced cases. We report a case of anorectal fistula cancer with widespread infiltration diagnosed during the course of Crohn's disease, which was curatively resected after preoperative chemoradiotherapy.

CASE PRESENTATION

A 49-year-old man who had been diagnosed with Crohn's disease (ileocolonic type) at the age of 25 and was found to have an anorectal fistula and perianal abscess at the age of 44 was referred to our department with complaints of abdominal pain and diarrhea. Computed tomography (CT) showed anal stenosis due to a pelvic mass. Pathological analysis of a biopsy taken under general anesthesia indicated mucinous carcinoma. Magnetic resonance imaging (MRI) revealed infiltration into the prostate, seminal vesicles, levator ani muscle, and left internal obturator muscle, and the patient was diagnosed with cT4N0M0 cStage IIIB anorectal fistula cancer (UICC TNM classification 8th edition). After performing a laparoscopic sigmoid colostomy, chemoradiation therapy (capecitabine + oxaliplatin, 50.4 Gy/28fr) was initiated. The patient then underwent laparoscopic total pelvic exenteration, colonic conduit diversion, extensive perineal resection, and reconstruction using bilateral gluteus maximus flaps and a right rectus abdominis musculocutaneous flap. The pathological diagnosis was mucinous adenocarcinoma, pT4, and all margins were negative. No recurrence was evident 6 months after the operation without adjuvant chemotherapy.

CONCLUSION

We described a case of curative resection after preoperative chemoradiotherapy for anorectal fistula cancer with extensive invasion that was diagnosed during the course of Crohn's disease.An accumulation of cases is needed to determine the usefulness of preoperative chemoradiation therapy for local control of anorectal fistula cancer associated with Crohn's disease.

High Level Sacral Bone Resection for Locally Recurrent Rectal Cancer

BACKGROUND/AIM

Locally recurrent rectal cancer (LRRC) involving the upper sacrum is generally considered a contraindication for curative surgery. In the surgical management of LRRC, sacrectomy is frequently performed to secure clear resection margins. Nonetheless, the indications for high sacrectomy remain controversial due to potential postoperative complications, questions about radicality, and the increased complexity of the operation. Furthermore, comprehensive studies addressing this issue are notably absent. This study aimed to assess the feasibility, safety, and surgical prognosis in high sacrectomy for LRRC.

PATIENTS AND METHODS

All patients with LRRC who required concomitant sacrectomy, but did not include the inferior margin of the second sacral vertebra, between 2003 and 2014, were reviewed retrospectively.

RESULTS

Eight patients with a median age of 59 years were included in this study. The proximal resection line for sacral bone resection was the central part of the S1 vertebra in one patient, lower edge of the S1 vertebra in six patients, and central part of the S2 vertebra in one patient. Negative margin resection was achieved in five out of the eight patients. The median operative time was 922 min, and the median operative blood loss volume was 6,370 ml. Major complications included pelvic abscess (n=5), ileus (n=1), and pulmonary vein embolism (n=1), none of which proved fatal during the postoperative period. Both the 5-year local re-recurrence-free survival rate and the 5-year distant metastasis-free survival rate were 50% (4/8).

CONCLUSION

High sacrectomy is safe and feasible to achieve negative margins in patients with LRRC.

Treatment response prediction of neoadjuvant chemotherapy for rectal cancer by deep learning of colonoscopy images

In current clinical practice, several treatment methods, including neoadjuvant therapy, are being developed to improve overall survival or local recurrence rates for locally advanced rectal cancer. The response to neoadjuvant therapy is usually evaluated using imaging data collected before and after preoperative treatment or postsurgical pathological diagnosis. However, there is a need to accurately predict the response to preoperative treatment before treatment is administered. The present study used a deep learning network to examine colonoscopy images and construct a model to predict the response of rectal cancer to neoadjuvant chemotherapy. A total of 53 patients who underwent preoperative chemotherapy followed by radical resection for advanced rectal cancer at the Osaka University Hospital between January 2011 and August 2019 were retrospectively analyzed. A convolutional neural network model was constructed using 403 images from 43 patients as the learning set. The diagnostic accuracy of the deep learning model was evaluated using 84 images from 10 patients as the validation set. The model demonstrated a sensitivity, specificity, accuracy, positive predictive value and area under the curve of 77.6% (38/49), 62.9% (22/33), 71.4% (60/84), 74.5% (38/51) and 0.713, respectively, in predicting a poor response to neoadjuvant therapy. Overall, deep learning of colonoscopy images may contribute to an accurate prediction of the response of rectal cancer to neoadjuvant chemotherapy.

A case of fulminant amoebic colitis during systemic chemotherapy for gastric cancer

Amoebiasis is a parasitic infection caused by the protozoan, Entamoeba histolytica. At times, amoebiasis is activated under immunosuppressive conditions such as chemotherapy. We report a case of fulminant amoebic colitis resulting from an asymptomatic Entamoeba histolytica infection, which was activated by chemotherapy for gastric cancer. The patient developed diarrhea and fever after three courses of chemotherapy for gastric cancer and was diagnosed with acute enteritis. A colonoscopy and biopsy were performed because of the bloody stool. Histopathological findings revealed amoebic invasion of the rectum. Therefore, the patient was diagnosed with amoebic colitis and was treated with metronidazole. Emergency surgery was performed because intestinal perforation was suspected after which his general condition improved and was discharged. Subsequently, gastric cancer surgery was performed and the patient was discharged without postoperative complications. Hence, amoebic colitis should be listed as a differential diagnosis, and a colonoscopic biopsy should be performed when colitis occurs during chemotherapy for cancer.

Cancer Stem Cells Persist Despite Cellular Damage, Emergence of the Refractory Cell Population

PURPOSE

Cancer stem cells (CSCs) are responsible for chemotherapy resistance and have unique properties that protect them from chemotherapy. Investigating CSCs may help to identify the population that is more resistant to treatments, leading to recurrence. We evaluated persisting CSCs, emerging after chemotherapy that cause tumor recurrence.

METHODS

Using human colorectal cancer organoids prepared from surgical specimens, we looked at changes in CSCs, the emergence and changes in the original population, which single-cell analysis identified.

RESULTS

With regards to changes in cancer stem cell markers, CD44 showed low levels after 5-fluorouracil administration. Once the CD44-ve population was sorted and cultured, the CD44+ve population gradually emerged, and the CD44-ve population decreased. Compared with the CD44-ve population of an organoid parent, the CD44-ve population proliferated after chemotherapeutic agent stimulation. The CD44-ve population was derived from the CD44+ve population before chemotherapeutic agents. In addition, when the CD44 variants were evaluated, the CD44v9 population remained. In single-cell analysis, we found that POU5F1 was highly expressed in the CD44low population. Velocity analysis showed that the CD44-ve population was induced after chemotherapy and expressed POU5F1. POU5F1-EGFP-Casp9 transfected organoids resulted in the appearance of a CD44-ve population after administration of a chemotherapeutic reagent. Both in vivo and in vitro, the dimerizer administration inhibited tumor growth significantly.

CONCLUSIONS

POU5F1 is involved in chemotherapy resistance in relation to stemness. For the treatment against refractory tumors, such as the recurrence after chemotherapy, the treatment should target the emerging specific population such as CD44 (or CD44v9) and proliferative cancer cells.

Surgery for Rectal Cancer With Mixed Reality of 3D Model During Operation: A Case Report

Background/Aim

Recently, robotic surgery for rectal cancer has become a common minimally invasive surgery. In addition, the technology of augmented and mixed reality is applied in various living environments, including medicine. We successfully performed robotic surgery for rectal cancer with three-dimensional (3D) images as mixed reality (MR) using HoloLens2.

Case Report

The patient was diagnosed with rectal cancer by colonoscopy and a positron-emission computed-tomography scan, and we performed robot-assisted anterior resection. The operator used HoloLens2 and performed the surgery while visualizing 3D images of pelvic anatomy with the location of the rectal cancer as hologram. The operation was performed completely and safely, and she was discharged 11 days after surgery with no postoperative complications.

Conclusion

This case presents the usefulness of a MR system offering organ visualization as hologram during surgery.

The Clinical Potential of FBPA-PET/CT Imaging for Colorectal Cancer and its Liver Metastases Expressing LAT1

BACKGROUND/AIM

18F-fluoro-deoxy-glucose positron emission tomography (18F-FDG PET) has become indispensable for staging colorectal cancer but has limitations. Thus, PET with a focus on metabolism other than glucose, mainly amino acid metabolism, has been developed. L-type amino acid transporter 1 (LAT1) is known to be a cancer-specific amino acid transporter and, although 4-Borono-2-(18)F-fluoro-phenylalanine (FBPA) has been reported to be useful as a probe for LAT1, the significance of LAT1 expression in colorectal cancer is ambiguous and implementation of 18F-FBPA-PET in colorectal cancer has not yet been reported.

MATERIALS AND METHODS

The aims of this study were to investigate the expression of LAT1 in primary lesions and metastatic lesions of colorectal cancer by immunohistochemical analysis and report the initial experience of performing 18F-FBPA-PET on colorectal cancer patients in clinical practice.

RESULTS

There was a significant correlation between LAT1 protein expression in primary tumors and liver metastases. Furthermore LAT-1 expression was positively correlated with recurrence (p=0.033). We performed 18F-FBPA-PET on three rectal cancer patients and detected cancer.

CONCLUSION

LAT1 protein is expressed not only in the primary colorectal tumor, but also in liver metastases. 18F-FBPA-PET can be safely performed in patients with colorectal cancer.

A Case of Rectal Cancer with Vaginal Invasion Using Indocyanine Green to Determine the Extent of Resection

Here we report a case of locally advanced rectal cancer with vaginal invasion, which was successfully resected via laparoscopic surgery using intraoperative indocyanine green (ICG) navigation to determine the vaginal cut line. Based on preoperative examinations, an 81-year-old female was diagnosed with locally advanced rectal cancer with vaginal invasion. After preoperative chemoradiotherapy, the lesion was judged to be resectable. During surgery, the gynecologist transvaginally injected ICG into the vaginal submucosa to determine the caudal margin of the vaginal invasion, and laparoscopically dissected under the near-infrared image of the stained area. Pathological analysis of the resection specimen revealed negative resection margins. One year after surgery, there has been no recurrence.

Pan-cancer and cross-population genome-wide association studies dissect shared genetic backgrounds underlying carcinogenesis

Integrating genomic data of multiple cancers allows de novo cancer grouping and elucidating the shared genetic basis across cancers. Here, we conduct the pan-cancer and cross-population genome-wide association study (GWAS) meta-analysis and replication studies on 13 cancers including 250,015 East Asians (Biobank Japan) and 377,441 Europeans (UK Biobank). We identify ten cancer risk variants including five pleiotropic associations (e.g., rs2076295 at DSP on 6p24 associated with lung cancer and rs2525548 at TRIM4 on 7q22 nominally associated with six cancers). Quantifying shared heritability among the cancers detects positive genetic correlations between breast and prostate cancer across populations. Common genetic components increase the statistical power, and the large-scale meta-analysis of 277,896 breast/prostate cancer cases and 901,858 controls identifies 91 newly genome-wide significant loci. Enrichment analysis of pathways and cell types reveals shared genetic backgrounds across said cancers. Focusing on genetically correlated cancers can contribute to enhancing our insights into carcinogenesis.

Testicular metastasis 9 years after resection of primary descending colon cancer with simultaneous pulmonary metastasis: a case report

BACKGROUND

Metastatic testicular cancer is rare. In particular, primary colorectal cancer rarely metastasizes to the testes. This study reports a case of testicular metastasis recurrence 9 years after the resection of a primary colorectal cancer and a simultaneous metastatic lung tumour.

CASE PRESENTATION

A 69-year-old man underwent a laparoscopic left hemicolectomy for descending colon cancer. Preoperative computed tomography revealed a solitary left lung mass. Postoperative chemotherapy reduced the size of the lung mass, and 6 months after the primary resection, the patient underwent a left upper segmentectomy. Based on the pathological examination, he was diagnosed with pulmonary metastasis from colorectal cancer. After four courses of adjuvant chemotherapy, the patient was recurrence-free. However, 9 years and 6 months after the primary resection, he complained of discomfort in his left testicle. Physical examination revealed a left testicular mass. Since a malignancy was not excluded via imaging, left testicular resection was performed to confirm the diagnosis. The pathological diagnosis was testicular metastasis from colorectal cancer. The patient was followed up without medication, and remained healthy, without recurrence, 11 months postoperatively.

CONCLUSIONS

It is important to follow up with testicular metastasis in mind, although it is rare.

Establishment of induced pluripotent stem cells derived from patients and healthy siblings of a nevoid basal cell carcinoma syndrome family

It is known that a nevoid basal cell carcinoma syndrome (NBCCS) is characterized by a combination of developmental abnormalities and a predisposition to form various tumors. Although it is possible to create disease models via gene editing, there are significant potential problems with this approach such as off-target mutations and differences in SNPs. On the other hand, since disease families share common SNPs, research using iPSCs derived from both patients and healthy siblings of the same disease family is very important. Thus, establishment of induced pluripotent stem cells derived from patients and healthy siblings of the same NBCCS family will be of great importance to study the etiology of this disease and to develop therapeutics. In this study, we generated hiPSCs using peripheral blood mononuclear cells derived from the patients and healthy siblings of familial NBCCS with the novel mutation in PTCH1_c.3298_3299insAAG in the feeder- and serum-free culture conditions using SeVdp. In addition, disease-specific hiPSCs such as those expressing the PTCH1_c.3298_3299insAAG mutation could be powerful tools for revealing the genotype-phenotype relationship and pathogenicity of NBCCS.

Tumor-suppressive role of the musculoaponeurotic fibrosarcoma gene in colorectal cancer

Somatic cell reprogramming using the microRNAs miR-200c, miR-302s, and miR-369s leads to increased expression of cyclin-dependent kinase inhibitors in human colorectal cancer (CRC) cells and suppressed tumor growth. Here, we investigated whether these microRNAs inhibit colorectal tumorigenesis in CPC;Apc mice, which are prone to colon and rectal polyps. Repeated administration of microRNAs inhibited polyp formation. Microarray analysis indicated that c-MAF, which reportedly shows oncogene-like behavior in multiple myeloma and T cell lymphoma, decreased in tumor samples but increased in microRNA-treated normal mucosa. Immunohistochemistry identified downregulation of c-MAF as an early tumorigenesis event in CRC, with low c-MAF expression associated with poor prognosis. Of note, c-MAF expression and p53 protein levels were inversely correlated in CRC samples. c-MAF knockout led to enhanced tumor formation in azoxymethane/dextran sodium sulfate-treated mice, with activation of cancer-promoting genes. c-MAF may play a tumor-suppressive role in CRC development.

Super Carbonate Apatite-miR-497a-5p Complex Is a Promising Therapeutic Option against Inflammatory Bowel Disease

The incidence of inflammatory bowel disease (IBD) is increasing worldwide. It is reported that TGF-β/Smad signal pathway is inactivated in patients with Crohn's disease by overexpression of Smad 7. With expectation of multiple molecular targeting by microRNAs (miRNAs), we currently attempted to identify certain miRNAs that activate TGF-β/Smad signal pathway and aimed to prove in vivo therapeutic efficacy in mouse model. Through Smad binding element (SBE) reporter assays, we focused on miR-497a-5p. This miRNA is common between mouse and human species and enhanced the activity of TGF-β/Smad signal pathway, decreased Smad 7 and/or increased phosphorylated Smad 3 expression in non-tumor cell line HEK293, colorectal cancer cell line HCT116 and mouse macrophage J774a.1 cells. MiR-497a-5p also suppressed the production of inflammatory cytokines TNF-α, IL-12p40, a subunit of IL-23, and IL-6 when J774a.1 cells were stimulated by lipopolysaccharides (LPS). In a long-term therapeutic model for mouse dextran sodium sulfate (DSS)-induced colitis, systemic delivery of miR-497a-5p load on super carbonate apatite (sCA) nanoparticle as a vehicle restored epithelial structure of the colonic mucosa and suppressed bowel inflammation compared with negative control miRNA treatment. Our data suggest that sCA-miR-497a-5p may potentially have a therapeutic ability against IBD although further investigation is essential.

[A Case of Squamous Cell Carcinoma of the Lower Rectum]

A 61-year-old man presented with dyschezia, and further examination revealed squamous cell carcinoma of the lower rectum invading the bladder and seminal vesicles. The clinical diagnosis was squamous cell carcinoma of the lower rectum, cT4b(bladder and seminal vesicle)N0M0, cStage Ⅱc. Neoadjuvant chemoradiotherapy was administered with external irradiation of the entire pelvis(50.4 Gy/28 Fr)and chemotherapy with 5-fluorouracil, Leucovorin, and oxaliplatin(FOLFOX). Once tumor shrinkage was observed 3 months after chemoradiotherapy, laparoscopic total pelvic exenteration with TaTME approach was performed. The patient was discharged on the 26th postoperative day without any postoperative complications. Histopathological examination showed only squamous cell carcinoma component with Grade 1a histological treatment effect. The pathological diagnosis was ypT4b(bladder, seminal vesicle)ypN0cM0, ypStage Ⅱc. The patient was alive without any recurrence 6 months after surgery.

Cancer-specific tissue-resident memory T-cells express ZNF683 in colorectal cancer

BACKGROUND

Tissue-resident memory T (Trm) cells are associated with cytotoxicity not only in viral infection and autoimmune disease pathologies but also in many cancers. Tumour-infiltrating CD103⁺ Trm cells predominantly comprise CD8 T cells that express cytotoxic activation and immune checkpoint molecules called exhausted markers. This study aimed to investigate the role of Trm in colorectal cancer (CRC) and characterise the cancer-specific Trm.

METHODS

Immunochemical staining with anti-CD8 and anti-CD103 antibodies for resected CRC tissues was used to identify the tumour-infiltrating Trm cells. The Kaplan-Meier estimator was used to evaluate the prognostic significance. Cells immune to CRC were targeted for single-cell RNA-seq analysis to characterise cancer-specific Trm cells in CRC.

RESULTS

The number of CD103⁺/CD8⁺ tumour-infiltrating lymphocytes (TILs) was a favourable prognostic and predictive factor of the overall survival and recurrence-free survival in patients with CRC. Single-cell RNA-seq analysis of 17,257 CRC-infiltrating immune cells revealed a more increased zinc finger protein 683 (ZNF683) expression in cancer Trm cells than in noncancer Trm cells and in high-infiltrating Trm cells than low-infiltrating Trm in cancer, with an upregulated T-cell receptor (TCR)- and interferon-γ (IFN-γ) signalling-related gene expression in ZNF683⁺ Trm cells.

CONCLUSIONS

The number of CD103⁺/CD8⁺ TILs is a prognostic predictive factor in CRC. In addition, we identified the ZNF683 expression as one of the candidate markers of cancer-specific Trm cells. IFN-γ and TCR signalling and ZNF683 expression are involved in Trm cell activation in tumours and are promising targets for cancer immunity regulation.

MUC1-C Dictates PBRM1-Mediated Chronic Induction of Interferon Signaling, DNA Damage Resistance, and Immunosuppression in Triple-Negative Breast Cancer

The polybromo-1 (PBRM1) chromatin-targeting subunit of the SWI/SNF PBAF chromatin remodeling complex drives DNA damage resistance and immune evasion in certain cancer cells through mechanisms that remain unclear. STAT1 and IRF1 are essential effectors of type I and II IFN pathways. Here, we report that MUC1-C is necessary for PBRM1 expression and that it forms a nuclear complex with PBRM1 in triple-negative breast cancer (TNBC) cells. Analysis of global transcriptional (RNA-seq) and chromatin accessibility (ATAC-seq) profiles further demonstrated that MUC1-C and PBRM1 drive STAT1 and IRF1 expression by increasing chromatin accessibility of promoter-like signatures (PLS) on their respective genes. We also found that MUC1-C, PBRM1, and IRF1 increase the expression and chromatin accessibility on PLSs of the (i) type II IFN pathway IDO1 and WARS genes and (ii) type I IFN pathway RIG-I, MDA5, and ISG15 genes that collectively contribute to DNA damage resistance and immune evasion. In support of these results, targeting MUC1-C in wild-type BRCA TNBC cells enhanced carboplatin-induced DNA damage and the loss of self-renewal capacity. In addition, MUC1-C was necessary for DNA damage resistance, self-renewal, and tumorigenicity in olaparib-resistant BRCA1-mutant TNBC cells. Analysis of TNBC tumors corroborated that (i) MUC1 and PBRM1 are associated with decreased responsiveness to chemotherapy and (ii) MUC1-C expression is associated with the depletion of tumor-infiltrating lymphocytes (TIL). These findings demonstrate that MUC1-C activates PBRM1, and thereby chromatin remodeling of IFN-stimulated genes that promote chronic inflammation, DNA damage resistance, and immune evasion.

IMPLICATIONS

MUC1-C is necessary for PBRM1-driven chromatin remodeling in chronic activation of IFN pathway genes that promote DNA damage resistance and immunosuppression.

Tumor-infiltrating T cells as a risk factor for lymph node metastasis in patients with submucosal colorectal cancer

Approximately 10% of patients with colorectal cancer with submucosal invasion have lymph node metastasis. Pathological risk factors for lymph node metastasis have varying sensitivities and specificities. To predict the risk of lymph node metastasis, the identification of new risk factors is vital. Tumor-infiltrating T cells have been reported to improve the prognosis of many solid tumors. Therefore, the purpose of this study was to examine the relationship between lymph node metastasis and tumor-infiltrating T cells in patients with colorectal cancer with submucosal invasion. We examined CD8⁺ tumor-infiltrating T cells level as a risk factor for lymph node metastasis in patients with colorectal cancer with submucosal invasion. Using immunohistochemical staining, we identified CD8 + T cells in surgically resected specimens from 98 patients with SM-CRC. We showed that low CD8⁺ tumor-infiltrating T cells levels are positively correlated with lymph node metastasis. Furthermore, by combining the number of CD8⁺ tumor-infiltrating T cell and the number of CD103⁺ tumor-infiltrating T cells, the results showed a high positive predictive value for lymph node metastasis in cases with low numbers of both types of tumor-infiltrating T cells and a high negative predictive value in cases with high numbers of both types of tumor-infiltrating T cells.

Characterization of Serotype CD Mosaic Botulinum Neurotoxin in Comparison with Serotype C and A

Botulinum neurotoxin (BoNT), produced by Clostridium botulinum, cleaves proteins involved in neurotransmitter release, thereby triggering flaccid paralyses, which are responsible for botulism. BoNT is classified into seven serotypes (BoNT/A-G); BoNT/A and BoNT/B are used as medical therapeutics and anti-wrinkle reagents. In this study, we investigated the efficacy of BoNT/CD, a mosaic toxin of BoNT/C and BoNT/D, to assess its potential as a therapeutic alternative for BoNT/A. In a cultured neuron assay, BoNT/CD cleaved syntaxin and SNAP-25 with higher efficacy than BoNT/C and BoNT/A. Intramuscularly administrated BoNT/CD induced dose-dependent muscle paralysis, and the paralysis lasted ~21 days in a mouse digit abduction score assay (BoNT/A-induced paralysis lasted ~30 days). BoNT/C failed to induce local paralysis without systemic toxicity. Multiple alignment analyses of the amino acid sequences of the receptor binding domain (HC) of eight BoNT/CDs and two BoNT/Ds showed sequence clustering in five groups. Comparing BoNT/CD strain 003-9 (BoNT/CD003-9) and strain 6813 (BoNT/CD6813) showed that both BoNT/CDs displayed similar efficacies in cultured neurons, but BoNT/CD003-9 displayed higher efficacy in a mouse model than BoNT/CD6813. These findings suggest that BoNT/CD may be a potential alternative for patients who do not respond to existing BoNT-based therapeutics.

Clinical development and evaluation of plasma angiogenesis factors from phase II study of FOLFIRI plus ramucirumab with recurrent colorectal cancer refractory to adjuvant chemotherapy with oxaliplatin/fluoropyrimidine (RAINCLOUD): RAINCLOUD-TR

173

Background: Higher levels of vascular endothelial growth factor-D (VEGF-D) is a potential predictive biomarker for ramucirumab (Ram) efficacy on overall survival and progression-free survival (PFS) in Ram+FOLFIRI vs Placebo+FOLFIRI for bevacizumab (Bev) refractory metastatic colorectal cancer (mCRC). However, it is not clear whether VEGF-D acts as a predictive biomarker in pts who pretreated without Bev. RAINCLOUD showed the clinical benefit of FOLFIRI+ plus Ram for pts with recurrent CRC refractory to adjuvant chemotherapy (median PFS was 6.2 months (M); ESMO-GI 2022). RAINCLOUD-TR was designed as a prospective biomarker study estimating the association of biomarkers with Ram efficacy. Methods: Plasma sample collections were done at time points of pre-/ post-treatments in pts receiving FOLFIRI+Ram. Measurements of 17 factors (including VEGF-A, VEGF-D and PlGF) were performed by multiplex assay with Luminex technology. The high/ low groups were defined bases on the median plasma level at the baseline. Results: From September 2017 to September 2021, 81 plasma samples were collected from 48 pts and 32 pts in both pre/ and post treatment. Level of VEGF-A, VEGF-D, PlGF and TSP-2 were all significantly higher in post vs pre-treatment [Table]. The ORR analyses were as follows; VEGF-A, VEGF-D and PlGF in low vs high were 50.0%/33.3% (p=0.35, HR 1.97), 55.0% /33.3% (p=0.22, HR 2.39), and 60.0%/28.6% (p=0.35, HR 1.95). The PFS analyses were as follows; VEGF-A, VEGF-D, and PlGF in low vs high were 6.1M/6.0M (p=0.815, HR 0.92), 7.6M /5.6M (p=0.095, HR 0.56), and 8.0M/4.2M (p=0.014, HR 0.40). In other factors, low TSP-2 were better ORR (low vs high: 66.7%/20.0% (p=0.004, HR 7.54) and PFS 7.5M/4.3M (p=0.022, HR 0.45). Conclusions: In this exploratory study, PFS was numerically greater for pts with low vs high VEGF-D for Ram in pts with mCRC pretreated without Bev. VEGF-D may not be predictive biomarker, but TSP-2 may be a potential prognostic biomarker, further studies in larger cohorts are needed to confirm our results. Clinical trial information: UMIN000028678 . [Table: see text]

Single-Cell Analysis of Circulating Tumor Cells from Patients with Colorectal Cancer Captured with a Dielectrophoresis-Based Micropore System

This study aimed to analyze circulating tumor cells (CTCs) from patients with colorectal cancer (CRC). We designed a dielectrophoresis-based micropore system and tested its cell capture with HT29 colon cancer cells. Then, blood samples were drawn from 24 patients with stages II-IV CRC. Mononuclear cells were isolated and loaded into the micropore system. Single cells were positioned into small pores with dielectrophoresis. After labeling the cells with the appropriate antibodies, tumor-like cells were collected with an automated micromanipulator. We collected 43 CTCs from 15 out of 24 patient samples. The presence of CTC was significantly associated with ling metastasis. We performed whole genome amplification, followed by PCR and Sanger sequencing, to examine the point mutations in the KRAS, BRAF, and PIK3CA genes. This mutation analysis was successfully performed in 35 cells. Among the 14 cytokeratin (CK)-positive cells, we found PIK3CA mutations in three cells (21%) from two patients. Among the 21 CK-negative cells, we found a KRAS mutation in one cell (5%) from one patient and a PIK3CA mutation in one cell (5%) from one patient. It is noteworthy that these mutations were not detected in the corresponding primary tumors. In conclusion, dielectrophoresis-based capture in a micropore system was useful for detecting both CK-positive and CK-negative CTCs. This simple method could be applied to various tumor types.

[Perineal Wound Complications after Abdominoperineal Resection for Anorectal Lesions]

BACKGROUND

Perineal wound complications(PWCs)are common after abdominoperineal resection(APR). We examined the incidence of PWCs after APR for anorectal lesions and their risk factors.

METHODS

Patients who underwent APR for anorectal lesions at our hospital from January 2011 to December 2021 were included. Complications of Clavien-Dindo Grade Ⅱ or higher were considered as PWCs.

RESULTS

Eighty-one patients were included; PWCs were observed in 24 patients (29.6%), and associated with a history of Crohn's disease(p=0.018), longer operation time(p=0.040), higher blood loss (p=0.011), extensive perineal resection(p=0.003), and closure with a skin flap(p=0.003). Forty-one patients underwent APR for initial rectal cancer without extended perineal resection, and PWCs were observed in 9 patients(22.0%). Prognostic nutritional index(PNI)<45(p=0.049), smoking(p=0.034), and alcohol consumption(p=0.021)were associated with PWCs.

CONCLUSION

We examined the incidence of PWCs after APR for anorectal lesions and their risk factors. Appropriate intervention in nutrition, smoking, and alcohol consumption may prevent PWCs.

Diagnosis of Depth of Submucosal Invasion in Colorectal Cancer with AI Using Deep Learning

The submucosal invasion depth predicts prognosis in early colorectal cancer. Although colorectal cancer with shallow submucosal invasion can be treated via endoscopic resection, colorectal cancer with deep submucosal invasion requires surgical colectomy. However, accurately diagnosing the depth of submucosal invasion via endoscopy is difficult. We developed a tool to diagnose the depth of submucosal invasion in early colorectal cancer using artificial intelligence. We reviewed data from 196 patients who had undergone a preoperative colonoscopy at the Osaka University Hospital and Osaka International Cancer Institute between 2011 and 2018 and were diagnosed pathologically as having shallow submucosal invasion or deep submucosal invasion colorectal cancer. A convolutional neural network for predicting invasion depth was constructed using 706 images from 91 patients between 2011 and 2015 as the training dataset. The diagnostic accuracy of the constructed convolutional neural network was evaluated using 394 images from 49 patients between 2016 and 2017 as the validation dataset. We also prospectively tested the tool from 56 patients in 2018 with suspected early-stage colorectal cancer. The sensitivity, specificity, accuracy, and area under the curve of the convolutional neural network for diagnosing deep submucosal invasion colorectal cancer were 87.2% (258/296), 35.7% (35/98), 74.4% (293/394), and 0.758, respectively. The positive predictive value was 84.4% (356/422) and the sensitivity was 75.7% (356/470) in the test set. The diagnostic accuracy of the constructed convolutional neural network seemed to be as high as that of a skilled endoscopist. Thus, endoscopic image recognition by deep learning may be able to predict the submucosal invasion depth in early-stage colorectal cancer in clinical practice.

Complete subunit structure of serotype C and D botulinum progenitor toxin complex induces vacuolation in the specific epithelial cell line

Clostridium botulinum produces seven botulinum neurotoxin (BoNT) serotypes. In nature, BoNT exists as a part of the progenitor toxin complex (PTC) through associations with neurotoxin associated proteins (NAPs), including nontoxic nonhemagglutinin and hemagglutinin (HA) complex, consists of HA-70, HA-17 and HA-33. Because PTC displays higher oral toxicity than pure BoNTs, NAPs play a critical role in food poisoning. In a previous study, we demonstrated that the NAP complex in mature large-sized PTC (L-PTC) from serotypes C and D concomitantly induced cell death and cytoplasmic vacuolation in the rat intestinal epithelial cell line IEC-6. Here, we found that the serotype D NAP complex induces only cytoplasmic vacuolation in the normal rat kidney cell line NRK-52E without reducing cell viability. NAP complexes from serotype A and B L-PTCs did not affect cell viability or cytoplasmic vacuolation in IEC-6 and NRK-52E cells. Furthermore, we assessed the effect of immature L-PTCs with fewer HA-33/HA-17 trimers (two HA-33 and one HA-17) than mature L-PTCs on cell viability and cytoplasmic vacuolation in IEC-6 and NRK-52E cells. As a result, mature L-PTCs with the maximum number of HA-33/HA-17 trimers displayed the greatest potency. Consequently, the reduction in cell viability and vacuolation induction are related to the number of HA-33/HA-17 trimers in PTC. The discovery of an epithelial cell model where botulinum PTC specifically induces vacuolization may help clarify the unknown cytotoxicity of PTC, which plays an important role in the trans-epithelial transport of the toxin.

Impact of the COVID-19 pandemic on colorectal cancer surgery in Japan: Clinical Study Group of Osaka University-A multicenter retrospective study

Aim

Due to the overwhelming spread of SARS-CoV-2 and its disruption of the healthcare system, delays and reduced numbers were reported for colorectal cancer screening, colonoscopies, and surgery during the COVID-19 pandemic. This multicenter retrospective study investigated the still poorly understood impact of the COVID-19 pandemic on colorectal cancer treatment in Japan.

Methods

This study was organized by the Clinical Study Group of Osaka University, which comprised 32 major institutions in Osaka. We retrospectively analyzed the number of surgeries and colonoscopies performed and the characteristics of patients who underwent surgery for colorectal cancer between March 2019 and February 2021. We compared data collected before and during the COVID-19 pandemic. We also assessed the methods used for detecting colorectal cancer, including fecal occult blood test, abdominal symptoms, and anemia.

Results

The COVID-19 pandemic caused reductions in the annual numbers of surgeries (3569 vs 3198) and colonoscopies (67 622 vs 58 183) performed in the 2020 fiscal year, compared to the 2019 fiscal year. During the COVID-19 pandemic, a significantly lower proportion of patients were treated for clinical stages ≤I (24.2% vs 26.9%; P = .011), compared to the proportion treated before the pandemic. Fecal occult blood tests for detecting colorectal cancer were used significantly less frequently during the COVID-19 pandemic (26.2% vs 29.6%; P = .002). These trends were more significant in larger institutions.

Conclusion

The COVID-19 pandemic reduced the number of colonoscopies and surgeries performed for colorectal cancer and hindered the detection of asymptomatic early-stage cancers, and its impact varied by hospital size.

Efficacy of PET/CT in diagnosis of regional lymph node metastases in patients with colorectal cancer: retrospective cohort study

Background

Endoscopic and transanal local resection without lymph node dissection are treatment options for patients with a low risk of lymph node metastasis; however, some patients might have undiagnosed lymph node metastases before surgery. This retrospective study aimed to evaluate the efficacy of preoperative PET/CT for diagnosing regional lymph node metastasis.

Methods

Patients who underwent curative resection with lymph node dissection for colorectal cancer at Osaka University between January 2012 and December 2015 were included. The cut-off values appropriate for diagnosing lymph node metastasis were calculated by way of a receiver operating characteristic (ROC) curves from maximum standard unit value (SUVmax) of main tumour, and lymph node short axis, and SUVmax of lymph node. The cut-off values of primary tumour SUVmax: 7, short-axis diameter of the lymph node at 7 mm, and lymph node SUVmax at 1.5 were set.

Result

A total of 541 patients were included. Regional lymph node metastases were confirmed in resected specimens from 187 patients (35 per cent). With a primary tumour SUVmax of 7 used as a cut-off value, the sensitivity and specificity of regional lymph node metastasis were 70.1 per cent and 45.5 per cent respectively. With a cut-off short-axis diameter of the regional lymph node of 7 mm, the sensitivity and specificity of regional lymph node metastasis were 75.2 per cent and 82.6 per cent respectively, and with a cut-off regional lymph node SUVmax of 1.5, the sensitivity and specificity of regional lymph node metastasis were 78.6 per cent and 96.8 per cent respectively. When the diagnostic criteria were defined by a lymph node short-axis diameter of 7 mm or SUVmax of 1.5, the sensitivity and specificity were 87.4 per cent and 81.8 per cent respectively.

Conclusion

Preoperative PET/CT is a useful modality for evaluating regional lymph node metastasis in patients with colorectal cancer.

The Geriatric Nutritional Risk Index as a Prognosis Predictor in Patients With Rectal Cancer Receiving Neoadjuvant Chemotherapy

BACKGROUND/AIM

There are few reports on the clinical significance of the geriatric nutritional risk index (GNRI) in patients with locally advanced rectal cancer who undergo preoperative chemotherapy (NAC, neoadjuvant chemotherapy) followed by radical resection; this study examined the relationship between preoperative GNRI, postoperative complications, and prognosis in these patients.

PATIENTS AND METHODS

Fifty-seven patients with rectal cancer who underwent radical resection after NAC at Osaka University Hospital between November 2011 and May 2018 were included. The GNRI was calculated as follows: GNRI= [1.489×serum albumin level (g/l)]+[41.7×present/ideal body weight (kg)]. Patients were classified into high (GNRI ≥96.74; n=36) and low GNRI (GNRI <96.74; n=21) groups, based on the results of the receiver operating characteristic curve analysis.

RESULTS

The Kaplan-Meier analysis showed that the low GNRI group had a significantly poorer cancer-specific survival (CSS) and a poorer overall survival tendency than the high GNRI group. In the univariate analysis, venous invasion, lymphatic vessel invasion, and low GNRI were significantly correlated with CSS; depth of tumor invasion, lymph node metastasis, and lymphatic vessel invasion were significantly correlated with disease-free survival (DFS). In the multivariate analysis, there were no significantly poor prognostic factors for CSS and DFS.

CONCLUSION

Preoperative GNRI may be a useful predictor for recurrence and poor prognosis in elderly patients with rectal cancer who undergo radical resection after NAC. Further studies and accumulation of cases should investigate the relationship between preoperative GNRI and prognosis after NAC in elderly patients.

Abstract 2630: Heterogeneity inducible tumor stem cells relate distant metastasis and the treatment resistance

Regarding metastatic potential of cancer cells and the refractory status, regulatory and epigenetic factors underlie the cancer treatment resistance by inducing cellular heterogeneity. Circulating tumor cells (CTCs) and their stemness are critical for metastases formation associated with poor survival rates. In colorectal cancer (CRC), several stem-cell markers, such as CD44v9 and LGR5, the positive cells cause intertumoral heterogeneity and promote refractory potential. However, the mastermind of the cells which is critical for the treatment resistance remains unknown. Here, we aimed to identify the mechanisms of the treatment resistance of the CRC by focusing on typical stem cells. We selected several stem cell-related genes such as pluripotency related genes, based on the expression profile analysis of CRC patients along with drug susceptibility assays using patient-derived organoids. Despite the small number of cancer stem cells, the single cell produced heterogeneous cell populations in vitro and in vivo, expressing various differentiation and stem biomarkers, and confirmed by the knockdown analysis. Single-cell trajectory analysis suggested that heterogeneous populations including cancer stem and some persister cells were derived from the stem cells following administration of anti-cancer drugs. Furthermore, the stem cells formed heterogeneous liver metastases at a high rate, and these unique cells were observed in the bloodstream of CRC patients. This present study unveils a mechanism of CRC treatment resistance and highlights the potential of stem marker-expressing cells as CTCs.

Citation Format: Norikatsu Miyoshi, Shiki Fujino, Yuki Sekido, Tsuyoshi Hata, Takayuki Ogino, Hidekazu Takahashi, Mamoru Uemura, HIrofumi Yamamoto, Yuichiro Doki, Hidetoshi Eguchi. Heterogeneity inducible tumor stem cells relate distant metastasis and the treatment resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2630.

Low G9a expression is a tumor progression factor of colorectal cancer via IL-8 promotion

The histone methyltransferase G9a is expressed in various types of cancer cells, including colorectal cancer (CRC) cells. Interleukin (IL)-8, also known as C-X-C motif chemokine ligand 8 (CXCL8), is a chemokine that plays a pleiotropic function in the regulation of inflammatory responses and cancer development. Here, we examined the relationship between G9a and IL-8 and the clinical relevance of this association. We immunohistochemically analyzed 235 resected CRC samples to correlate clinical features. Samples with high G9a expression had better overall survival and relapse-free survival than those with low G9a expression. Univariate and multivariate analyses demonstrated that low G9a expression remained a significant independent prognostic factor for increased disease recurrence and decreased survival (P<0.05). G9a was expressed at high levels in commercially available CRC cell lines HCT116 and HT29. Knockdown of G9a by siRNA, shRNA, or the G9a-specific inhibitor BIX01294 upregulated IL-8 expression. The number of spheroids was significantly increased in HCT116 cells with stably suppressed G9a expression, and the number of spheroids was significantly decreased in HCT116 cells with stably suppressed IL-8 expression. Thus, the suppression of IL-8 by G9a may result in a better prognosis in CRC cases with high G9a expression. Furthermore, G9a may suppress cancer stemness and increase chemosensitivity by controlling IL-8. Therefore, G9a is a potential novel marker for predicting CRC prognosis, and therapeutic targeting of G9a in CRC should be contraversial.

Locally advanced rectal cancer receiving total neoadjuvant therapy combined with nivolumab: a case report and literature review

BACKGROUND

The standard treatment for locally advanced rectal cancer (LARC) is preoperative chemoradiotherapy (CRT) followed by surgery and adjuvant chemotherapy. However, it has been suggested that intensification of neoadjuvant treatment with polychemotherapy in addition to CRT instead of as an adjuvant chemotherapy is better tolerated and associated with a higher pathological complete response (pCR) rate. This concept is known as total neoadjuvant therapy (TNT). Recently, the addition of immunotherapy to preoperative CRT has been reported to be useful in LARC patients with mismatch-repair-deficiency and high levels of microsatellite instability (MSI-H), but there are no reports showing the therapeutic effect of nivolumab in combination with TNT.

CASE PRESENTATION

A 23-year-old man had frequent diarrhea. Preoperative examination revealed two adenocarcinomas in the rectum. His maternal grandmother had a rectal cancer patient who developed the disease at age 70s. The larger tumor was located at the peritoneal reflection, and its anterior border close to the prostate (<1 mm); there were eight enlarged pararectal lymph nodes. Considering the size and depth of the tumor, it was judged that radical resection with sufficient margins would be difficult. Therefore, it was decided that TNT would be performed. At first, CAPOX (capecitabine and L-OHP) was administered, followed by preoperative CRT (RT:50.4 Gy and capecitabine). During this period, genetic testing diagnosed this patient as MSI-H, so additional nivolumab was administered after CRT. Colonoscopy revealed that the larger tumor was no longer detectable, so robot-assisted intersphincteric resection and bilateral lateral lymph node dissection was performed. The diagnosis of pCR was made for the larger tumor and partial response was achieved for the smaller tumor, and no lymph node metastasis was found. Major complications were not observed and the patient was discharged on the 14th day after surgery. He was followed up without adjuvant chemotherapy and is alive and recurrence-free after 9 months.

CONCLUSION

A case of LARC with MSI-H was treated with TNT with nivolumab, resulting in pCR and complete radical resection. This result suggests that nivolumab in addition to TNT can be an option as a preoperative strategy for LARC with MSI-H.

Targeting MUC1-C Suppresses Chronic Activation of Cytosolic Nucleotide Receptors and STING in Triple-Negative Breast Cancer

Simple Summary

Triple-negative breast cancers (TNBCs) are recalcitrant tumors with limited therapeutic options. Cytotoxic agents, including platinum-based drugs, are a standard of care for advanced TNBCs. Olaparib is also used for the treatment of germline BRCA mutant TNBC tumors in the adjuvant and recurrent disease settings. Notably, however, the effectiveness of these genotoxic agents is often limited by intrinsic and adaptive DNA damage resistance. We demonstrate in TNBC cells that the oncogenic MUC1-C protein chronically activates the type I interferon (IFN) pathway, drives the cGAS/STING axis and induces expression of the DNA damage resistance gene signature (IRDS). Targeting MUC1-C inhibits activation of this pathway in the response to carboplatin and olaparib and sensitizes TNBC cells to these agents. These findings indicate that MUC1-C is a target, which is druggable, for overcoming the obstacle of DNA damage resistance in the treatment of TNBCs.

Abstract

The MUC1-C apical transmembrane protein is activated in the acute response of epithelial cells to inflammation. However, chronic MUC1-C activation promotes cancer progression, emphasizing the importance of MUC1-C as a target for treatment. We report here that MUC1-C is necessary for intrinsic expression of the RIG-I, MDA5 and cGAS cytosolic nucleotide pattern recognition receptors (PRRs) and the cGAS-stimulator of IFN genes (STING) in triple-negative breast cancer (TNBC) cells. Consistent with inducing the PRR/STING axis, MUC1-C drives chronic IFN-β production and activation of the type I interferon (IFN) pathway. MUC1-C thereby induces the IFN-related DNA damage resistance gene signature (IRDS), which includes ISG15, in linking chronic inflammation with DNA damage resistance. Targeting MUC1-C in TNBC cells treated with carboplatin or the PARP inhibitor olaparib further demonstrated that MUC1-C is necessary for expression of PRRs, STING and ISG15 and for intrinsic DNA damage resistance. Of translational relevance, MUC1 significantly associates with upregulation of STING and ISG15 in TNBC tumors and is a target for treatment with CAR T cells, antibody–drug conjugates (ADCs) and direct inhibitors that are under preclinical and clinical development.

High postoperative carcinoembryonic antigen as an indicator of high‑risk stage II colon cancer

Postoperative carcinoembryonic antigen (post-CEA) has recently been reported to be a reliable prognostic factor for colon cancer. However, most clinicians decide whether or not to conduct adjuvant chemotherapy (AC) for stage II colon cancer according to major guidelines, which do not include post-CEA in their high-risk criteria. The present study aimed to assess post-CEA in stage II colon cancer for which the significance of AC is unknown. The present study analyzed 199 consecutive patients with stage II colon cancer who underwent curative surgery between January 2007 and December 2016. The CEA value was considered high when it was ≥5.0 ng/ml. The prognostic value of high post-CEA values was assessed. Overall, 19 patients exhibited high post-CEA levels. Kaplan-Meier survival curve analysis demonstrated that patients with high post-CEA levels had significantly worse relapse-free survival (RFS) and overall survival (OS) than those with normal post-CEA [RFS, 63.5 (high post-CEA) vs. 88.0% (normal post-CEA), P=0.003; OS, 76.5 (high post-CEA) vs. 96.8% (normal post-CEA), P<0.001]. Multivariate analysis demonstrated that high post-CEA remained a significant independent risk factor for worse RFS [hazard ratio (HR), 3.98; P=0.006]. The same was also demonstrated for patients without AC (HR, 5.43; P=0.008). To the best of our knowledge, the present study was the first to demonstrate that high post-CEA levels may be an indicator of high-risk stage II colon cancer, even for patients without AC. These results highlight the need for a multicenter prospective study.

Colorectal Surgery in the COVID-19 Pandemic Era

The novel coronavirus disease 2019 (COVID-19) caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread at a very fast rate, overwhelming and disrupting healthcare systems around the world since its outbreak in December 2019 in China. As of October 2021, the total number of COVID-19 cases exceeds 240,000,000, and the total number of deaths is close to 5,000,000. In the situation of widespread SARS-CoV-2 infection, restrictions on the medical system due to shifts in medical care to accommodate the pandemic will occur, and its impact on surgical and endoscopic treatment for colorectal cancer is inevitable. Therefore, it is necessary to satisfy all of the following requirements: patient safety, prevention of exposure of healthcare workers including surgeons, prevention of nosocomial infection, and a decision on how to treat the primary disease. Surgical triage is also required, based on comprehensive consideration of the patient's condition, the severity of the disease, the SARS-CoV-2 infection situation in the region, and the medical supply system at each facility, including medical resources, human resources, and the availability of medical equipment. Understanding the diagnostic and treatment environment that the COVID-19 pandemic has dramatically changed is important in providing appropriate surgical care to patients who require surgery while taking utmost care to prevent the spread of COVID-19.

[Laparoscopic Left Hemicolectomy for Advanced Descending Colon Cancer in Patient with Idiopathic Pulmonary Arterial Hypertension-Report of a Case]

We experienced a case of laparoscopic left hemicolectomy for advanced descending colon cancer in patient with idiopathic pulmonary arterial hypertension(IPAH). The patient was a 39-year-old woman. She visited her family doctor in November 201X because of bowel movement disturbance and melena. She was diagnosed as advanced descending colon cancer. Although intraoperative management for hemodynamic stability was expected to be difficult due to IPAH, hemodynamic stability was achieved under 10 mmHg pneumoperitoneum. During the operation noradrenaline and phenylephrine were used for hemodynamic management. Laparoscopic left hemicolectomy was performed safely. Postoperative histopathological findings were as follows; Type 2, tub1>tub2, pT4a(SE), pN1a(1/65), int, INF b, ly1, v1, Pn1b, pPM0, pDM0, pStage Ⅲb(the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma, 9th edition). The patient was discharged from the hospital on the 18th day after surgery without any complications except for Grade 2 diarrhea, which was considered a side effect of PGI2 preparation.

Interaction of Eating Status and Dietary Variety on Incident Functional Disability among Older Japanese Adults

OBJECTIVES

To examine whether eating status and dietary variety were associated with functional disability during a 5-year follow-up analysis of older adults living in a Japanese metropolitan area.

DESIGN

A 5-year follow-up study.

SETTING

Ota City, Tokyo, Japan.

PARTICIPANTS

A total of 10,308 community-dwelling non-disabled adults aged 65-84 years.

MEASUREMENTS

Eating status was assessed using a self-reported questionnaire. Dietary variety was assessed using the dietary variety score (DVS). Based on the responses, participants were classified according to eating alone or together and DVS categories (low: 0-3; high: 4-10). Functional disability incidence was prospectively identified using the long-term care insurance system's nationally unified database. Multilevel survival analyses calculated the adjusted hazard ratio (HR) and 95% confidence interval (CI) for incident functional disability.

RESULTS

During a 5-year follow-up, 1,991 (19.3%) individuals had functional disabilities. Eating status or DVS were not independently associated with incident functional disability. However, interaction terms between eating status and DVS were associated with functional disability; HR (95% CI) for eating together and low DVS was 1.00 (0.90-1.11), eating alone and high DVS was 0.95 (0.77-1.17), and eating alone and low DVS was 1.20 (1.02-1.42), compared to those with eating together and high DVS.

CONCLUSION

Older adults should avoid eating alone or increase dietary variety to prevent functional disability. This can be ensured by providing an environment of eating together or food provision services for eating a variety of foods in the community.

Improved In Vivo Delivery of Small RNA Based on the Calcium Phosphate Method

In the past few years, we have demonstrated the efficacy of a nanoparticle system, super carbonate apatite (sCA), for the in vivo delivery of siRNA/miRNA. Intravenous injection of sCA loaded with small RNAs results in safe, high tumor delivery in mouse models. To further improve the efficiency of tumor delivery and avoid liver toxicity, we successfully developed an inorganic nanoparticle device (iNaD) via high-frequency ultrasonic pulverization combined with PEG blending during the production of sCA. Compared to sCA loaded with 24 μg of miRNA, systemic administration of iNaD loaded with 0.75 μg of miRNA demonstrated similar delivery efficiency to mouse tumors with little accumulation in the liver. In the mouse therapeutic model, iNaD loaded with 3 μg of the tumor suppressor small RNA MIRTX resulted in an improved anti-tumor effect compared to sCA loaded with 24 μg. Our findings on the bio-distribution and therapeutic effect of iNaD provide new perspectives for future nanomedicine engineering.

Long Distance Between the Superior Mesenteric Artery Root and Bottom of the External Anal Sphincter Is a Risk Factor for Stoma Outlet Obstruction After Total Proctocolectomy and Ileal‐Pouch Anal Anastomosis for Ulcerative Colitis

Background

Stoma outlet obstruction (SOO) is much more common after total proctocolectomy (TPC) and ileal‐pouch anal anastomosis (IPAA) for ulcerative colitis (UC) compared to after rectal surgery for cancer. Few prior reports have evaluated anatomical risk factors for SOO. In this study we aimed to clarify the risk factors for SOO after IPAA, focusing on the anatomical perspective.

Methods

This study included 68 UC patients who underwent IPAA with diverting ileostomy. These cases were analyzed based on clinicopathological factors and computed tomography (CT)‐based anatomical factors.

Results

SOO was identified in 18 patients (26.5%). We compared this SOO group with the non‐SOO group. The two groups significantly differed in sex distribution, and patients in the SOO group tended to have a longer postoperative hospital stay. Regarding surgery‐related factors, patients who underwent two‐stage surgery and experienced high‐output syndrome tended to develop SOO. Analysis of anatomical risk factors revealed that SOO was more common in patients with a longer distance between the root of their superior mesenteric artery and the bottom of the external anal sphincter (rSMA‐bEAS). This tendency remained significant even with adjustment for patient height. In multivariate analyses, adjusted rSMA‐bEAS (>191.0 mm/m) and male sex were independent risk factors associated with SOO.

Conclusion

A long rSMA‐bEAS distance suggests that the mesentery is likely to be under tension. In such cases, surgeons should endeavor to avoid tension in the mesentery as much as possible.

Defecation Function After Laparo-Assisted Restorative Proctocolectomy with Ileal Pouch Anal Anastomosis for Ulcerative Colitis

Background: Defecation status is an important determinant of quality of life. Previous studies showed that postoperative defecation disorders occurred after open surgery for ulcerative colitis (UC), but few have investigated defecation status after laparo-assisted surgery. The added precision and magnification provided with laparo-assisted surgery should lead to less damage to the anal sphincter muscle. This study investigated defecation function after a laparo-assisted restorative proctocolectomy (RPC) with ileal pouch anal anastomosis (IPAA). We also clarified factors that worsened defecation status. Methods: This retrospective study included 57 patients who underwent laparo-assisted RPC with IPAA for UC from January 2000 to May 2019. At 1 year after surgery, functional outcomes were evaluated with the Kirwan classification and Wexner score. Risk factors for poor defecation status were investigated with multiple regression. Results: At 1 year after surgery, the median Kirwan classification score was 2 and the median Wexner score was 8. Defecation disorder was observed in 19 (33.3%) patients, according to the Kirwan classification, and 15 (26.3%) patients, according to the Wexner score. Hand-sewn IPAA was associated with defecation disorder (P = .04), evaluated with the Kirwan classification. Hand-sewn IPAA (P = .01), older age (P = .03), high body mass index (P = .04), and the surgical indication (cancer/dysplasia; P = .03) were significantly associated with defecation disorder, evaluated with the Wexner score. The multivariable analysis showed that hand-sewn IPAA was an independent risk factor (P = .049; odds ratio: 4.99; 95% confidence interval: 1.0-28.39). Conclusions: We found that hand-sewn IPAA was a risk factor for defecation disorders after laparo-assisted RPC for UC.

Specific activation of glycolytic enzyme enolase 2 in BRAF V600E-mutated colorectal cancer

The BRAF V600E mutation occurs in approximately 10% of patients with metastatic colorectal cancer (CRC) and constitutes a distinct subtype of the disease with extremely poor prognosis. To address this refractory disease, we investigated the unique metabolic gene profile of BRAF V600E‐mutated tumors via in silico analysis using a large‐scale clinical database. We found that BRAF V600E‐mutated tumors exhibited a specific metabolic gene expression signature, including some genes that are associated with poor prognosis in CRC. We discovered that BRAF V600E‐mutated tumors expressed high levels of glycolytic enzyme enolase 2 (ENO2), which is mainly expressed in neuronal tissues under physiological conditions. In vitro experiments using CRC cells demonstrated that BRAF V600E‐mutated cells exhibited enhanced dependency on ENO2 compared to BRAF wild‐type cancer cells and that knockdown of ENO2 led to the inhibition of proliferation and migration of BRAF V600E‐mutated cancer cells. Moreover, inhibition of ENO2 resulted in enhanced sensitivity to vemurafenib, a selective inhibitor of BRAF V600E. We identified AP‐1 transcription factor subunit (FOSL1) as being involved in the transcription of ENO2 in CRC cells. In addition, both MAPK and PI3K/Akt signaling were suppressed upon inhibition of ENO2, implying an additional oncogenic role of ENO2. These results suggest the crucial role of ENO2 in the progression of BRAF V600E‐mutated CRC and indicate the therapeutic implications of targeting this gene.

Efficacy of positron emission tomography in diagnosis of lateral lymph node metastases in patients with rectal Cancer: a retrospective study

BACKGROUND

The presence of lateral pelvic lymph node (LLN) metastasis is an essential prognostic factor in rectal cancer patients. Thus, preoperative diagnosis of LLN metastasis is clinically important to determine the therapeutic strategy. The aim of this study was to evaluate the efficacy of preoperative positron emission tomography/computed tomography (PET/CT) in the diagnosis of LLN metastasis.

METHODS

Eighty-four patients with rectal cancer who underwent LLN dissection at Osaka University were included in this study. The maximum standardized uptake value (SUV_max) of the primary tumor and LLN were preoperatively calculated using PET/CT. Simultaneously, the short axis of the lymph node was measured using multi-detector row computed tomography (MDCT). The presence of metastases was evaluated by postoperative pathological examination.

RESULTS

Of the 84 patients, LLN metastases developed in the left, right, and both LLN regions in 6, 7, and 2 patients, respectively. The diagnosis of the metastases was predicted with a sensitivity of 82%, specificity of 93%, positive predictive value of 58%, negative predictive value of 98%, false positive value of 7%, and false negative value of 18% when the cutoff value of the LLN SUV_max was set at 1.5. The cutoff value of the short axis set at 7 mm on MDCT was most useful in diagnosing LLN metastases, but SUV_max was even more useful in terms of specificity.

CONCLUSIONS

The cutoff value of 1.5 for lymph node SUV_max in PET is a reasonable measure to predict the risk of preoperative LLN metastases in rectal cancer patients.

MUC1-C integrates activation of the IFN-γ pathway with suppression of the tumor immune microenvironment in triple-negative breast cancer

Background

Immune checkpoint inhibitors (ICIs) have had a profound impact on the treatment of many tumors; however, their effectiveness against triple-negative breast cancers (TNBCs) has been limited. One factor limiting responsiveness of TNBCs to ICIs is a lack of functional tumor-infiltrating lymphocytes (TILs) in ‘non-inflamed’ or ‘cold’ tumor immune microenvironments (TIMEs), although by unknown mechanisms. Targeting MUC1-C in a mouse transgenic TNBC tumor model increases cytotoxic tumor-infiltrating CD8+ T cells (CTLs), supporting a role for MUC1-C in immune evasion. The basis for these findings and whether they extend to human TNBCs are not known.

Methods

Human TNBC cells silenced for MUC1-C using short hairpin RNAs (shRNAs) were analyzed for the effects of MUC1-C on global transcriptional profiles. Differential expression and rank order analysis was used for gene set enrichment analysis (GSEA). Gene expression was confirmed by quantitative reverse-transcription PCR and immunoblotting. The The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) datasets were analyzed for effects of MUC1 on GSEA, cell-type enrichment, and tumor immune dysfunction and exclusion. Single-cell scRNA-seq datasets of TNBC samples were analyzed for normalized expression associations between MUC1 and selected genes within tumor cells.

Results

Our results demonstrate that MUC1-C is a master regulator of the TNBC transcriptome and that MUC1-C-induced gene expression is driven by STAT1 and IRF1. We found that MUC1-C activates the inflammatory interferon (IFN)-γ-driven JAK1→STAT1→IRF1 pathway and induces the IDO1 and COX2/PTGS2 effectors, which play key roles in immunosuppression. Involvement of MUC1-C in activating the immunosuppressive IFN-γ pathway was extended by analysis of human bulk and scRNA-seq datasets. We further demonstrate that MUC1 associates with the depletion and dysfunction of CD8+ T cells in the TNBC TIME.

Conclusions

These findings demonstrate that MUC1-C integrates activation of the immunosuppressive IFN-γ pathway with depletion of TILs in the TNBC TIME and provide support for MUC1-C as a potential target for improving TNBC treatment alone and in combination with ICIs. Of translational significance, MUC1-C is a druggable target with chimeric antigen receptor (CAR) T cells, antibody-drug conjugates (ADCs) and a functional inhibitor that are under clinical development.

[Laparoscopic Abdominoperineal Resection Following Intensive Chemotherapy for Stage Ⅳ Rectal Cancer with Unresectable Metastases]

The need to remove palliative primary tumors in the incurable Stage Ⅳ colorectal cancer patients remains debatable. Here, we describe the case of a 62-year-old man diagnosed with rectal cancer(cT3N2bM1b, cStage Ⅳb)with both primary tumor and metastatic lesions that were unresectable. Systemic chemotherapy was administered with 5-fluorouracil, Leucovorin, and oxaliplatin(FOLFOX)or FOLFOX with bevacizumab(BEV). After 12 months of treatment, CT scan revealed that both the primary tumor and metastases had shrunk significantly, leading to the conclusion that the primary tumor was resectable. Subsequently, laparoscopic abdominoperineal resection was performed. The patient was discharged 21 days postoperatively, and chemotherapy(FOLFOX plus BEV)was reintroduced 24 days after discharge. The patient was alive 25 months after the first consultation. Palliative primary tumor resection involves risks of operative complications and tumor progression owing to the absence of chemotherapy; however, some recent evidence has shown that primary tumor resection was associated with better prognosis and could be a good option on an individual patient basis. Further studies are required to establish the optimal strategy for patients with Stage Ⅳ colorectal cancer.