High serum proteinase-3 levels predict poor progression-free survival and lower efficacy of bevacizumab in metastatic colorectal cancer

BACKGROUND

To improve the prognosis of patients with metastatic colorectal cancer (mCRC), investigating predictive biomarkers of their prognosis and chemotherapeutic responsiveness is necessary. This study aimed to analyze the clinical significance of serum proteinase-3 (PRTN3) as a predictor for prognosis and chemosensitivity, especially to bevacizumab therapy, in mCRC.

METHODS

This single-center retrospective observational study enrolled 79 patients with mCRC in our hospital and 353 patients with colorectal cancer in the TCGA database. Preoperative serum PRTN3 levels were measured using an enzyme-linked immunosorbent assay. The clinicopathological characteristics and prognosis according to serum PRTN3 levels were then evaluated. PRTN3 expression in tumor and stromal cells was evaluated immunohistochemically. The impact of PRTN3 levels on angiogenesis and bevacizumab sensitivity was evaluated using the tube formation assay.

RESULTS

Serum PRTN3 levels were an independent poor prognostic factor for progression-free survival (PFS) (hazard ratio, 2.082; 95% confidence interval, 1.118-3.647; P=0.010) in patients with mCRC. Similarly, prognostic analysis with TCGA data sets showed poorer overall survival in patients with PRTN3 expression than that in patients without PRTN3 expression, especially in patients with stage IV. Immunohistochemical analysis of resected specimens revealed that stromal neutrophils expressed PRTN3, and their expression level was significantly correlated with serum PRTN3 levels. Interestingly, the effectiveness of first-line chemotherapy was significantly poorer in the high serum PRTN3 level group. High serum PRTN3 was significantly associated with poor PFS (hazard ratio, 3.027; 95% confidence interval, 1.175-7.793; P=0.0161) in patients treated with bevacizumab, an anti-angiogenic inhibitor. The tube formation assay revealed that PRTN3 administration notably augmented angiogenesis while simultaneously attenuating the anti-angiogenic influence exerted by bevacizumab therapy.

CONCLUSIONS

Serum PRTN3 levels could be a novel predictive biomarker of PFS of first-line chemotherapy, especially for bevacizumab therapy, in patients with mCRC.

[A Recurrent Colon Cancer Successfully Treated by Nivolumab plus Ipilimumab with On and Off for Preventing Exacerbation of Skin Disorders]

Here, we report a case in which nivolumab plus ipilimumab combination therapy was significantly effective for MSI-high recurrent colon cancer with acute exacerbation after 5-FU/L-OHP/CPT-11 treatment. At the end of 4 cycles of combination therapy, clinical CR was obtained on diagnostic imaging. At the end of the 2 cycles of transition from combination therapy to monotherapy, eosinophilia was observed in a quadratic function, and exacerbation of skin disorders was observed. Eosinophil counts normalized promptly after discontinuation of treatment, and skin disorders gradually improved. Two months after the discontinuation of treatment, monotherapy was restarted. After the resumption of treatment, an increase in eosinophils and worsening of skin symptoms were observed again, and stopped treatment. We report an interesting case in which immune checkpoint inhibiter were turned on and off according to eosinophil counts for preventing exacerbation of skin disorders, and for maintaining cancer remission by continuing immune checkpoint inhibitor treatment.

IL-6 Levels Correlate with Prognosis and Immunosuppressive Stromal Cells in Patients with Colorectal Cancer

BACKGROUND

The prognosis for patients with colorectal cancer (CRC) is determined by tumor characteristics as well as the host immune response. This study investigated the relationship between an immunosuppressive state and patient prognosis by evaluating the systemic and tumor microenvironment (TME) interleukin (IL)-6 levels.

METHODS

Preoperative serum IL-6 levels were measured using an electrochemiluminescence assay. Expression of IL-6 in tumor and stromal cells was evaluated immunohistochemically in 209 patients with resected CRC. Single-cell analysis of tumor-infiltrating immune cells was performed using mass cytometry in 10 additional cases.

RESULTS

Elevated serum IL-6 levels were associated with elevated stromal IL-6 levels and a poor prognosis for patients with CRC. High IL-6 expression in stromal cells was associated with low-density subsets of CD3+ and CD4+ T cells as well as FOXP3+ cells. Mass cytometry analysis showed that IL-6+ cells among tumor-infiltrating immune cells were composed primarily of myeloid cells and rarely of lymphoid cells. In the high-IL-6-expression group, the percentages of myeloid-derived suppressor cells (MDSCs) and CD4+FOXP3highCD45RA- effector regulatory T cells (eTreg) were significantly higher than in the low-IL-6-expression group. Furthermore, the proportion of IL-10+ cells in MDSCs and that of IL-10+ or CTLA-4+ cells in eTregs correlated with IL-6 levels.

CONCLUSION

Elevated serum IL-6 levels were associated with stromal IL-6 levels in CRC. High IL-6 expression in tumor-infiltrating immune cells also was associated with accumulation of immunosuppressive cells in the TME.

A phase I study of a novel therapeutic vaccine as perioperative treatment for patients with surgically resectable hepatocellular carcinoma: The YCP02 trial

BACKGROUND

Developing effective adjuvant therapies is essential for improving the surgical outcomes in patients with hepatocellular carcinoma (HCC). Immunotherapy against HCC has become a promising strategy; however, only approximately 30% of all HCC patients respond to immunotherapy. Previously, we generated the novel therapeutic vaccine comprising multi-HLA-binding heat shock protein (HSP)70/glypican-3 (GPC3) peptides with a novel adjuvant combination of hLAG-3Ig and poly-ICLC. We also confirmed the safety of this vaccination therapy, as well as its capacity for the effective induction of immune responses in a previous clinical trial.

METHODS

In this phase I study, we administered this vaccine intradermally six times before surgery and ten times after surgery to patients with untreated, surgically resectable HCC (stage II to IVa). The primary endpoints of this study were the safety and feasibility of this treatment. We also analyzed the resected tumor specimens pathologically using hematoxylin and eosin staining and immunohistochemistry for HSP70, GPC3, CD8 and PD-1.

RESULTS

Twenty HLA-matched patients received this vaccination therapy with an acceptable side-effect profile. All patients underwent planned surgery without vaccination-related delay. Immunohistochemical analyses revealed that potent infiltration of CD8+ T cells into tumors with target antigen expression was observed in 12 of 20 (60%) patients.

CONCLUSIONS

This novel therapeutic vaccine was safe as perioperative immunotherapy for patients with HCC and has the potential to strongly induce CD8+ T cells infiltration into tumors. This article is protected by copyright. All rights reserved.

Development of multiple AI pipelines that predict neoadjuvant chemotherapy response of breast cancer using H&E-stained tissues

In recent years, the treatment of breast cancer has advanced dramatically and neoadjuvant chemotherapy (NAC) has become a common treatment method, especially for locally advanced breast cancer. However, other than the subtype of breast cancer, no clear factor indicating sensitivity to NAC has been identified. In this study, we attempted to use artificial intelligence (AI) to predict the effect of preoperative chemotherapy from hematoxylin and eosin images of pathological tissue obtained from needle biopsies prior to chemotherapy. Application of AI to pathological images typically uses a single machine-learning model such as support vector machines (SVMs) or deep convolutional neural networks (CNNs). However, cancer tissues are extremely diverse and learning with a realistic number of cases limits the prediction accuracy of a single model. In this study, we propose a novel pipeline system that uses three independent models each focusing on different characteristics of cancer atypia. Our system uses a CNN model to learn structural atypia from image patches and SVM and random forest models to learn nuclear atypia from fine-grained nuclear features extracted by image analysis methods. It was able to predict the NAC response with 95.15% accuracy on a test set of 103 unseen cases. We believe that this AI pipeline system will contribute to the adoption of personalized medicine in NAC therapy for breast cancer.

Anti-VEGF and Anti-EGFR Antibody Therapy on T-Cell Infiltration and TCR Variation in Metastatic Colorectal Cancer

BACKGROUND/AIM

Chemotherapy combined with anti-EGFR or anti-VEGF monoclonal antibodies (mAb) is widely used to treat patients with metastatic colorectal cancer (mCRC). Here, we investigated the effects of these antibodies on T-cell infiltration and T-cell receptor (TCR) repertoire variation in CRC liver metastases.

MATERIALS AND METHODS

Ten patients with mCRC received chemotherapy in combination with anti-EGFR (n=6) or anti-VEGF (n=4) mAb. T-cell infiltration was examined for CD3 and CD8 by carrying out immunohistochemistry on biopsy or surgical specimens from liver metastases before and after treatment. TCR repertoire analysis was carried out on specimens with post-treatment CD3⁺ T-cell infiltration.

RESULTS

T-cell infiltrations were approximately 83% (5/6) and 50% (2/4), following treatment with anti-EGFR or anti-VEGF mAb, respectively. TCR repertoire analysis revealed higher clonality and lower diversity of TCR alpha and beta (TRA and TRB) in the anti-VEGF mAb group than that in the anti-EGFR group mAb. Furthermore, the percentage of the common TCR clones between infiltrating T cells and T cells in peripheral blood was significantly lower in the anti-VEGF mAb group compared to that in the anti-EGFR mAb group.

CONCLUSION

The population of T cells infiltrating liver metastases in the anti-VEGF mAb group differed from that in the anti-EGFR mAb group.

Association between a single nucleotide polymorphism in the R3HCC1 gene and irinotecan toxicity

OBJECTIVE

Irinotecan is a useful anticancer drug for colorectal cancer treatment. UGT1A1*28 and *6 gene polymorphisms are known risk factors for irinotecan-associated toxicity. However, severe adverse effects due to irinotecan have been observed even in patients who do not harbor UGT1A1*28 or *6. We investigated gene polymorphisms in the whole exome to identify useful biomarkers for irinotecan toxicity other than UGT1A.

METHODS

A total of 178 patients with metastatic colorectal cancer (mCRC) and 87 patients with pancreatic cancer were treated with FOLFIRI, FOLFOX, FOLFOXIRI, modified FOLFIRINOX, or gemcitabine plus nab-paclitaxel. Genome-wide screening was performed using whole-exome sequencing (WES), and validation analysis was performed using qPCR with a hydrolysis probe.

RESULTS

Using WES after a doublet chemotherapy regimen comprising irinotecan and 5-fluorouracil (n = 15), seven single nucleotide polymorphisms (SNPs) were identified as candidate biomarkers for irinotecan-associated toxicity of neutropenia. Among the seven SNPs, an SNP in R3H domain and coiled-coil containing 1 (R3HCC1; c.919G > A, rs2272761) showed a significant association with neutropenia (>grade 3) after doublet chemotherapy. Patients receiving irinotecan including triplet chemotherapy, FOLFOXIRI for mCRC (n = 23) or modified FOLFIRINOX for pancreatic cancer (n = 40), also showed significant linear trends between R3HCC1 polymorphism and neutropenia (p = 0.017 and 0.046, respectively). No significant association was observed in patients treated with irinotecan-free regimens, FOLFOX for mCRC (n = 66), and gemcitabine plus nab-paclitaxel for pancreatic cancer (n = 47).

CONCLUSION

Thus, an SNP in the R3HCC1 gene may be a useful biomarker for the toxicity of irinotecan-containing chemotherapy for mCRC and pancreatic cancer.

Multicenter International Study of the Consensus Immunoscore for the Prediction of Relapse and Survival in Early-Stage Colon Cancer

Background: The prognostic value of Immunoscore was evaluated in Stage II/III colon cancer (CC) patients, but it remains unclear in Stage I/II, and in early-stage subgroups at risk. An international Society for Immunotherapy of Cancer (SITC) study evaluated the pre-defined consensus Immunoscore in tumors from 1885 AJCC/UICC-TNM Stage I/II CC patients from Canada/USA (Cohort 1) and Europe/Asia (Cohort 2). METHODS: Digital-pathology is used to quantify the densities of CD3+ and CD8+ T-lymphocyte in the center of tumor (CT) and the invasive margin (IM). The time to recurrence (TTR) was the primary endpoint. Secondary endpoints were disease-free survival (DFS), overall survival (OS), prognosis in Stage I, Stage II, Stage II-high-risk, and microsatellite-stable (MSS) patients. RESULTS: High-Immunoscore presented with the lowest risk of recurrence in both cohorts. In Stage I/II, recurrence-free rates at 5 years were 78.4% (95%-CI, 74.4−82.6), 88.1% (95%-CI, 85.7−90.4), 93.4% (95%-CI, 91.1−95.8) in low, intermediate and high Immunoscore, respectively (HR (Hi vs. Lo) = 0.27 (95%-CI, 0.18−0.41); p < 0.0001). In Cox multivariable analysis, the association of Immunoscore to outcome was independent (TTR: HR (Hi vs. Lo) = 0.29, (95%-CI, 0.17−0.50); p < 0.0001) of the patient’s gender, T-stage, sidedness, and microsatellite instability-status (MSI). A significant association of Immunoscore with survival was found for Stage II, high-risk Stage II, T4N0 and MSS patients. The Immunoscore also showed significant association with TTR in Stage-I (HR (Hi vs. Lo) = 0.07 (95%-CI, 0.01−0.61); P = 0.016). The Immunoscore had the strongest (69.5%) contribution χ2 for influencing survival. Patients with a high Immunoscore had prolonged TTR in T4N0 tumors even for patients not receiving chemotherapy, and the Immunoscore remained the only significant parameter in multivariable analysis. CONCLUSION: In early CC, low Immunoscore reliably identifies patients at risk of relapse for whom a more intensive surveillance program or adjuvant treatment should be considered.

Serum CCL7 Is a Novel Prognostic Biomarker of Metastatic Colorectal Cancer

BACKGROUND/AIM

Colorectal cancer is the third most common cancer globally, and the poor prognosis of patients with metastatic colorectal cancer (mCRC) warrants urgent attention. We previously obtained 10 candidate serum biomarkers for mCRC. Our aim with this study was to determine the prognostic performance of the pre-treatment serum C-C motif chemokine ligand 7 (CCL7) concentration in patients with mCRC.

PATIENTS AND METHODS

Protein concentrations of CCL7 were examined using ELISA and immunohistochemistry for serum (n=110) and surgical specimens (n=85), respectively, of patients with mCRC. The relationship between protein concentration and prognosis was examined using Cox regression analysis, receiver operator characteristic curve analysis and the Kaplan-Meier method.

RESULTS

The overall survival (OS) of patients with high concentrations of serum CCL7 was significantly poorer than that of patients with low concentrations. Patients with a high CCL7 concentration in the stroma had significantly poorer outcomes than those with a low concentration. The concentrations of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 were significantly higher in the high-CCL7 group, compared to those in the low-CCL7 group. Univariate and multivariate analysis revealed that serum CCL7 concentration was a significant prognostic factor for mCRC. The combination of serum CCL and CEA concentrations was also useful in this regard (area under the curve=0.71).

CONCLUSION

The combined pre-treatment serum levels of CCL7 and CEA are useful prognostic biomarkers for mCRC.

CD4 and FOXP3 as predictive markers for the recurrence of T3/T4a stage II colorectal cancer: applying a novel discrete Bayes decision rule

Background

We recently reported the relapse-free survival (RFS) significance of the combination of CD4⁺ and forkhead box P3⁺ (FOXP3) T-cell densities identified by immunohistochemistry in patients with stage I, II, and III colorectal cancer (CRC) who underwent curative resections. This study was designed to determine the optimal combination of markers that predict recurrence in patients with T factors of T3/T4a stage II CRC by applying a novel Bayes decision rule.

Methods

Using 137 cancer tissue specimens from T3/T4a stage II patients, 12 clinicopathologic and immune factors were analysed as predictive candidates for recurrence.

Results

Our study showed that the combination of low CD4⁺ and low FOXP3⁺ T-cell densities resulted in extremely poor RFS.

Conclusions

Adjuvant chemotherapy may be considered for patients with a combination of low CD4⁺ and low FOXP3⁺ T-cell densities. The discovery of this new prognostic indicator is important for the appropriate management of patients undergoing curative resection for T3/T4a stage II CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10181-7.

Clinical Performance of the Consensus Immunoscore in Colon Cancer in the Asian Population from the Multicenter International SITC Study

BACKGROUND: In this study, we evaluated the prognostic value of Immunoscore in patients with stage I−III colon cancer (CC) in the Asian population. These patients were originally included in an international study led by the Society for Immunotherapy of Cancer (SITC) on 2681 patients with AJCC/UICC-TNM stages I−III CC. METHODS: CD3+ and cytotoxic CD8+ T-lymphocyte densities were quantified in the tumor and invasive margin by digital pathology. The association of Immunoscore with prognosis was evaluated for time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS). RESULTS: Immunoscore stratified Asian patients (n = 423) into different risk categories and was not impacted by age. Recurrence-free rates at 3 years were 78.5%, 85.2%, and 98.3% for a Low, Intermediate, and High Immunoscore, respectively (HR[Low-vs-High] = 7.26 (95% CI 1.75−30.19); p = 0.0064). A High Immunoscore showed a significant association with prolonged TTR, OS, and DFS (p < 0.05). In Cox multivariable analysis stratified by center, Immunoscore association with TTR was independent (HR[Low-vs-Int+High] = 2.22 (95% CI 1.10−4.55) p = 0.0269) of the patient’s gender, T-stage, N-stage, sidedness, and MSI status. A significant association of a High Immunoscore with prolonged TTR was also found among MSS (HR[Low-vs-Int+High] = 4.58 (95% CI 2.27−9.23); p ≤ 0.0001), stage II (HR[Low-vs-Int+High] = 2.72 (95% CI 1.35−5.51); p = 0.0052), low-risk stage-II (HR[Low-vs-Int+High] = 2.62 (95% CI 1.21−5.68); p = 0.0146), and high-risk stage II patients (HR[Low-vs-Int+High] = 3.11 (95% CI 1.39−6.91); p = 0.0055). CONCLUSION: A High Immunoscore is significantly associated with the prolonged survival of CC patients within the Asian population.

[Tumor Immunogenicity and Immune Checkpoint Inhibitors]

Cancer immunotherapy including immune checkpoint inhibitors(ICIs)have established itself as the fourth cancer therapy. However, the response rate of ICIs is still only about 20%, and tumors resistant to ICIs are often so-called"cold-tumor"with low tumor immunogenicity. Therefore, research and development is being conducted worldwide on how to convert cold- tumors into hot-tumors with high immunogenicity. In this paper, we review the relationship between tumor immunogenicity and ICI, as well as therapeutic methods to enhance tumor immunogenicity, and introduce our research about novel cancer peptide vaccination therapy.

Immune Evasion of Hepatoma Cancer Stem-Like Cells from Natural Killer Cells

BACKGROUND

Poor prognosis in liver cancer is due to its high frequency of intrahepatic metastasis. Cancer stem-like cells (CSLCs), which possess the properties of stemness, tumor initiation capability, and resistance to therapy, also exhibit metastatic potential. Immune surveillance plays an important role in the accomplishment of metastasis. Herein, the property of immune evasion in CSLCs was investigated.

METHODS

Sphere cells were induced as CSLCs using a sphere induction medium containing neural survival factor-1. The expression of genes involved in immune evasion was determined using RNA-sequencing for sphere and parental cells followed by validation using flow cytometric analysis and ELISA. Susceptibility to natural killer (NK) cell-mediated cytotoxicity was examined by a chromium release assay. A xenograft model using BALB/c nu/nu mice was used to assess tumor growth. Gene set enrichment analysis was performed for interpreting RNA sequencing.

RESULTS

The cell surface expressions of PD-L1, PD-L2, and CEACAM1 were upregulated and those of ULBP1 and MICA/MICB were downregulated in SK-sphere, CSLCs derived from SK-HEP-1, compared with that in parental cells. Levels of soluble MICA were elevated in conditioned medium from SK-sphere. Expression of HLA class I was not downregulated in SK-sphere. The susceptibilities to NK cell-mediated killing and secreted perforin were significantly lower in both CSLCs derived from SK-HEP-1 and HLE than in parental cells. Tumors formed upon inoculation of SK-sphere in immunodeficient mice harboring NK cells were larger than those formed upon inoculation of parental cells.

CONCLUSION

Human hepatoma cell line-derived CSLCs may possess immune evasion properties, especially from NK cell-mediated immunity.

Comparison of two primer-probe sets of Fusobacterium nucleatum using droplet digital polymerase chain reaction for the detection of colorectal neoplasia from faecal samples

BACKGROUND

Although faecal DNA testing of Fusobacterium nucleatum (Fn) is expected to be useful for colorectal neoplasia detection, there is no standardized quantification method of Fn. We performed this study to establish a possible standardized method.

METHODS

In this study, 322 participants including 71 subjects without colorectal neoplasia (control group), 31 patients with non-advanced colorectal adenoma, 93 patients with advanced colorectal adenoma, and 127 patients with colorectal cancer were enrolled. Faecal Fn were quantified by droplet digital PCR (ddPCR) using two PCR primer-probe sets reported previously that are tentatively named Fn1 and Fn2. Fn1 has been used in ddPCR by us and Fn2 has been widely used in quantitative real-time PCR.

RESULTS

The Fn copy number using Fn1 was five times higher than that using Fn2, with a linear relationship shown between them. Receiver operating characteristic curve analysis showed the area under the curve (AUC) to be almost the same between Fn1 and Fn2 in discriminating between the control group and the colorectal cancer group (AUC = 0.81 and 0.81, respectively), and between the control/non-advanced colorectal adenoma group and the advanced colorectal adenoma/colorectal cancer group (AUC = 0.74 and 0.74, respectively).

CONCLUSIONS

As the diagnostic performance was quite similar between Fn1 and Fn2, ddPCR-based Fn testing using Fn1 and Fn2 could be a possible standardized method for a colorectal neoplasia screening test, considering that Fn levels quantified by Fn1 are about five times higher than those by Fn2.

Elevated expression of RAB3B plays important roles in chemoresistance and metastatic potential of hepatoma cells

Background

Cancer stem cells (CSCs) are thought to play important roles in carcinogenesis, recurrence, metastasis, and therapy-resistance. We have successfully induced cancer stem-like sphere cells (CSLCs) which possess enhanced chemoresistance and metastatic potential. To enable the development of targeted therapy against CSLCs, we identified a gene responsible for this phenotype in CSLC.

Methods

Human hepatoma cell line SK-HEP-1 was used for CSLC induction with a unique sphere inducing medium, and HuH-7 cells were used as non-sphere forming cells in the same condition. RNA-sequencing was performed followed by validation with quantitative RT-PCR and western blotting. Knockdown experiments were done by using CRISPR-Cas9 genome-editing, and the rescue experiments were performed using the expressing plasmid vector. Chemoresistance and liver metastasis of the cells, was studied following the splenic injection of cells to severely immune deficient mice and evaluated using the MTS assay. Quantification of exosomes in the medium was done using ELISA.

Results

RAB3B was identified as an up-regulated gene in both CSLCs and prognostically poor hepatocellular carcinoma (HCC) by RNA-sequencing. RAB3B-KD cells showed altered CSLC phenotypes such as sphere formation, chemoresistance, and metastatic potentials, and those were rescued by RAB3B complementation. Increased exosome secretion was observed in CSLCs, and it was not observed in the RAB3B-KD cells. In addition, the RAB3B expression correlated with the expression of ABCG2, APOE, LEPR, LXN, and TSPAN13.

Conclusion

The up regulation of RAB3B may play an important role in the chemoresistance and metastatic potential of CSLCs.

HLA Class I Analysis Provides Insight Into the Genetic and Epigenetic Background of Immune Evasion in Colorectal Cancer With High Microsatellite Instability

BACKGROUND & AIMS

A detailed understanding of antitumor immunity is essential for optimal cancer immune therapy. Although defective mutations in the B2M and HLA-ABC genes, which encode molecules essential for antigen presentation, have been reported in several studies, the effects of these defects on tumor immunity have not been quantitatively evaluated.

METHODS

Mutations in HLA-ABC genes were analyzed in 114 microsatellite instability-high colorectal cancers using a long-read sequencer. The data were further analyzed in combination with whole-exome sequencing, transcriptome sequencing, DNA methylation array, and immunohistochemistry data.

RESULTS

We detected 101 truncating mutations in 57 tumors (50%) and loss of 61 alleles in 21 tumors (18%). Based on the integrated analysis that enabled the immunologic subclassification of microsatellite instability-high colorectal cancers, we identified a subtype of tumors in which lymphocyte infiltration was reduced, partly due to reduced expression of HLA-ABC genes in the absence of apparent genetic alterations. Survival time of patients with such tumors was shorter than in patients with other tumor types. Paradoxically, tumor mutation burden was highest in the subtype, suggesting that the immunogenic effect of accumulating mutations was counterbalanced by mutations that weakened immunoreactivity. Various genetic and epigenetic alterations, including frameshift mutations in RFX5 and promoter methylation of PSMB8 and HLA-A, converged on reduced expression of HLA-ABC genes.

CONCLUSIONS

Our detailed immunogenomic analysis provides information that will facilitate the improvement and development of cancer immunotherapy.

[A Case of Pseudo-Meigs' Syndrome Caused by Ovarian Metastasis from Colon Cancer]

This case pertains to a female patient in her 60s who was diagnosed with carcinoma in the cecum with lung, ovarian, and peritoneal metastases. She complained of abdominal distension and poor feeding because her ascites and ovarian metastasis worsened 18 months after chemotherapy initiation. Repeated cytologic examination of the ascitic fluid revealed no malignant cells. Therefore, Pseudo-Meigs' syndrome was suspected. Bilateral salpingo-oophorectomy was performed as palliative surgery because of the patient's reduced capacity to perform activities of daily living(ADL)due to ascites. After palliative surgery, her ascites disappeared, and she was able to better perform ADL. Further, chemotherapy was resumed. The patient remains well 10 months after surgery. This case highlights the importance of considering Pseudo-Meigs' syndrome in patients with massive ascites and ovarian metastasis, because surgical resection can improve their quality of life.

[A Resected Case of Advanced Lower Rectal Cancer with Neoadjuvant Chemotherapy by FOLFOXIRI plus Cetuximab]

Although the current standard of care for patients with lower rectal cancer in Japan includes total mesorectal resection with lateral lymph node dissection, postoperative local and distant recurrence rates are high. Multidisciplinary treatment is important to improve the prognosis. A man in his 30s was diagnosed with lower rectal cancer due to bloody stool and referred to our department. He was diagnosed as cT3N3M0, cStage Ⅲc with right obturator lymph node metastasis. Four courses of neoadjuvant chemotherapy(NAC)with FOLFOXIRI plus cetuximab were performed. Because Grade 3 neutropenia was observed in the first cycle(CTCAE v5.0), pegfilgrastim was administered in the second and subsequent cycles, and NAC was completed without dose reduction. The patient underwent laparoscopy-assisted intersphincteric rectal resection and D3+rtLD2 dissection. Histopathological resection margins were negative, and the resection was R0. Lymph node metastasis was found only in No. 263d-rt, and the pathological diagnosis was ypT3N3M0, pStage Ⅲc. Histological evaluation of response to treatment was Grade 2. The postoperative course was good and the patient was discharged on postoperative day 15. The patient received 8 courses of adjuvant chemotherapy with mFOLFOX6 from the 7th postoperative week and is alive and recurrence-free 6 months after surgery.

Transcript-targeted analysis reveals isoform alterations and double-hop fusions in breast cancer

Although transcriptome alteration is an essential driver of carcinogenesis, the effects of chromosomal structural alterations on the cancer transcriptome are not yet fully understood. Short-read transcript sequencing has prevented researchers from directly exploring full-length transcripts, forcing them to focus on individual splice sites. Here, we develop a pipeline for Multi-Sample long-read Transcriptome Assembly (MuSTA), which enables construction of a transcriptome from long-read sequence data. Using the constructed transcriptome as a reference, we analyze RNA extracted from 22 clinical breast cancer specimens. We identify a comprehensive set of subtype-specific and differentially used isoforms, which extended our knowledge of isoform regulation to unannotated isoforms including a short form TNS3. We also find that the exon-intron structure of fusion transcripts depends on their genomic context, and we identify double-hop fusion transcripts that are transcribed from complex structural rearrangements. For example, a double-hop fusion results in aberrant expression of an endogenous retroviral gene, ERVFRD-1, which is normally expressed exclusively in placenta and is thought to protect fetus from maternal rejection; expression is elevated in several TCGA samples with ERVFRD-1 fusions. Our analyses provide direct evidence that full-length transcript sequencing of clinical samples can add to our understanding of cancer biology and genomics in general.

Anti-cancer activity of amorphous curcumin preparation in patient-derived colorectal cancer organoids

Despite its adverse effects, chemotherapy is generally used for the treatment of colorectal cancer (CRC). Development of supplement preparations targeting cancer stem cells (CSCs) that cause distant metastasis and drug resistance is required. Although curcumin is known to have anti-tumor, hepatoprotective, and hypoglycemic-like actions, its low water solubility, oral absorption, and bioavailability impede its therapeutic uses. Patient-derived organoid cultures can recapitulate heterogeneity, epithelial structures, and molecular imprints of their parental tissues. In the present study, anti-carcinogenic properties of amorphous curcumin (AC), a compound with improved solubility and bioavailability, were evaluated against human CRC organoids. Treatment with AC inhibited the cell viability of CRC organoids in a concentration-dependent manner. AC arrested the cell cycle of CRC organoids and induced apoptosis. AC inhibited phosphorylation of ERK. Expression of downstream signals of ERK, namely c-MYC and cyclin-D1, were inhibited. Expressions of CSC markers, CD44, LGR5, and CD133, were declined in the AC-treated CRC organoids. The combinational treatment of CRC organoids with AC and anti-cancer drugs, oxaliplatin, 5-FU, or irinotecan showed a synergistic activity. In vivo, AC decreased the tumor growth of CRC organoids in mice with the induction of necrotic lesions. In conclusion, AC diminished the cell viability of CRC organoids through the inhibition of proliferation-related signals and CSC marker expression in addition to arresting the cell cycle. Collectively, these data suggest the value of AC as a promising supplement that could be used in combination with anti-cancer drugs to prevent the recurrence and metastasis of CRC.

Laparoscopic Sutureless Rectopexy Using a Fixation Device for Complete Rectal Prolapse

BACKGROUND

Complete rectal prolapse (CRP) commonly affects the daily life of older people and has no established operative treatment approach. We describe our simple method of laparoscopic, sutureless rectopexy, involving rectal mobilization (along with its peritoneum bilaterally) and fixation to the sacral promontory using a fixation device. We also present an analysis of short-term outcomes in patients treated using this procedure.

MATERIALS AND METHODS

We retrospectively evaluated 62 patients with CRP, who underwent a laparoscopic rectopexy via tack fixation, between 2004 and 2017. The peritoneum was widely attached near the site of peritoneal reflection, as in rectal cancer surgery. The hypogastric nerve was carefully detached from the front of the sacrum. Keeping the nerve intact, we lifted and mobilized the dissected rectum cranially towards the promontory, and the rectal peritoneum was affixed to the sacrum by applying 2 to 3 fixed tacks bilaterally, using a fixation device.

RESULTS

The median age of the study group was 80 (10 to 91) years. All procedures were successful without serious intraoperative complications; only 1 patient required conversion to open surgery. Median values for operative duration, intraoperative blood loss, and postoperative period of hospitalization were 177 (125 to 441) minutes, 5 (0 to 275) mL, and 7 (3 to 17) days, respectively. Only 6 (9.7%) patients experienced recurrence during the follow-up period.

CONCLUSION

Laparoscopic tacking rectopexy performed using a fixation device for repairing CRP is a simple, safe, and sutureless procedure with no severe complications or mortality.

Pancreatic Cancer Stem-Like Cells With High Calreticulin Expression Associated With Immune Surveillance

OBJECTIVE

Pancreatic cancer stem-like cells (P-CSLCs) are thought to be associated with poor prognosis. Previously, we used proteomic analysis to identify a chaperone pro-phagocytic protein calreticulin (CALR) as a P-CSLC-specific protein. This study aimed to investigate the association between CALR and P-CSLC.

METHODS

PANC-1-Lm cells were obtained as P-CSLCs from a human pancreatic cancer cell line, PANC-1, using a sphere induction medium followed by long-term cultivation on laminin. To examine the cancer stem cell properties, subcutaneous injection of the cells into immune-deficient mice and sphere formation assay were performed. Cell surface expression analysis was performed using flow cytometry.

RESULTS

PANC-1-Lm showed an increased proportion of cell surface CALR-positive and side-population fractions compared with parental cells. PANC-1-Lm cells also had higher frequency of xenograft tumor growth and sphere formation than PANC-1 cells. Moreover, sorted CALRhigh cells from PANC-1-Lm had the highest sphere formation frequency among tested cells. Interestingly, the number of programmed death-ligand 1-positive cells among CALRhigh cells was increased as well, whereas that of human leukocyte antigen class I-positive cells decreased.

CONCLUSION

In addition to the cancer stem cell properties, the P-CSLC, which showed elevated CALR expression on the cell surface, might be associated with evasion of immune surveillance.

[Immune-Related Factors as Prognostic Markers for Resectable Colorectal Cancer]

BACKGROUND

Tumor infiltration of CD3 and CD8-positive T cells has been reported as a good prognostic marker for patients with colorectal cancer(CRC). To clarify the significance of CD4 and FOXP3-positive T cells in CRC for prognosis of intratumoral infiltration.

METHODS

CD3, CD8, CD4 and FOXP3-positive T cells were immunostained(IHC)from tissue specimens of 342 CRC patients who underwent curative resection to quantify the number of infiltrating cells in the tumor. Microsatellite instability(MSI)was also evaluated in 322 samples and the clinicopathological factors and survival were analyzed.

RESULTS

Highly infiltrated groups of CD3, CD4 and FOXP3-positive T cells were associated with improved relapse-free survival(RFS). Highly infiltrated groups of CD8, CD4 and FOXP3-positive T cells were associated with improved disease- specific survival(DSS). Invasion depth, vascular infiltration, and CD4-positive T cell density were independent prognostic factors for DSS. CD4 and FOXP3-positive T cell infiltration was not associated with the high-frequency microsatellite instability group, in contrast to CD3 and CD8-positive T cell infiltration.

CONCLUSIONS

Intratumoral CD4-positive T cell density and FOXP3-positive T cell densities were stronger prognostic indicators than other clinicopathological features. These results may facilitate the establishment of novel prognostic factors and therapeutic strategies for CRC.