Corrigendum to "MIF-CD74 axis facilitates MDSC infiltration in the tumor microenvironment of pancreatic ductal adenocarcinoma" [Cancer Lett. 645, (2026), 218348].
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Biomedical subjects
Publications and source records attributed to Kazunori Aoki.
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Immune checkpoint inhibitors show insufficient efficacy against pancreatic ductal adenocarcinoma (PDAC). The tumor microenvironment (TME) has a remarkable influence on responsiveness to cancer immunotherapy. The aim of this study was to investigate immunosuppressive characteristics of TME in PDAC tissues. The flow cytometry (FCM) of PDAC surgical specimens revealed that the profile of tumor-infiltrating leukocytes was classified into myeloid cell- and T-cell-dominant subtypes; the myeloid subtype was associated with poorer patient outcomes. Myeloid-derived suppressor cells (MDSCs) showed the highest hazard ratio among various myeloid cell types. Single-cell RNA sequencing and FCM revealed that most MDSCs, but not lymphocytes, in PDAC tissues characteristically express CD74. Macrophage migration inhibitory factor (MIF), a CD74 ligand, was highly expressed in cancer-associated fibroblasts (CAFs) and cancer cells. Spatial transcriptomics demonstrated that the MIF-CD74+ myeloid cell interaction was recognized in CAF-dominant areas in PDAC tissue. CAFs expressing immune suppressor molecules such as MFAP5 and LRRC15 were consistent with MIF+ CAFs. Furthermore, MIF+ CAFs enhanced the migratory activity of MDSCs and promoted MDSC induction and activation. In the murine model, MDSCs were significantly increased in MIF-expressing PDAC tumors, as were CD74+ M-MDSCs per M-MDSC, confirming in vivo interaction between CD74 and MIF. MDSCs play a crucial role in creating an immunosuppressive TME in PDAC; the MIF-CD74 axis drives interactions between MDSCs and CAFs.
Enhancement of the specific antitumor activity of allogeneic hematopoietic stem cell transplantation (alloHSCT) against solid cancers is a major issue in the clinical oncology. In this study, we examined whether intratumoral allogeneic MHC (alloMHC) gene transfer can enhance the recognition of tumor-associated antigens by donor T cells and augment the antitumor activity of alloHSCT. In minor histocompatibility antigen-mismatched alloHSCT (DBA/2-->BALB/c: H-2(d)) recipients, alloMHC gene (H-2K(b)) was transduced directly into a s.c. tumor of CT26 colon cancer cells. Because CT26 cells have an aggressive tumorigenicity in syngeneic BALB/c mice, an H-2K(b) gene transfer provides only a limited antitumor effect after syngeneic (BALB/c-->BALB/c) HSCT. By contrast, the H-2K(b) gene transfer caused significant tumor suppression in the alloHSCT recipients, and this suppression was evident not only in the gene-transduced tumors but also in simultaneously inoculated distant tumors without gene transduction. In vitro cytotoxicity assay showed specific tumor cell lysis by donor T cells responding to the H-2K(b) gene transfer. Graft-versus-host disease was not exacerbated serologically or clinically in the treated mice, demonstrating that alloMHC gene transfer enhances the antitumor effects of alloHSCT without exacerbating graft-versus-host disease. This combination strategy has important implications for the development of therapies for human solid cancers.
We believe that this is the first report of a retroperitoneal tumor consisting of heterotopic gastrointestinal mucosa and pancreatic tissue. The patient was a 19-year-old woman with the chief complaint being occasional back pain. Abdominal computerized tomography demonstrated a 3.1 x 2.5 x 3.2-cm low-density solid and cystic lesion adjoining the left renal vein between the aorta and inferior vena cava. Angiography revealed that the inferior vena cava was displaced by the hypovascular tumor. The retroperitoneal lesion was diagnosed preoperatively as a benign tumor such as a neurogenic neoplasm or lymphangioma. At laparotomy, a cystic tumor was found, which existed behind the inferior vena cava and renal vessels, and contained reddish-brown fluid, suggesting hemorrhage in the past. The cut surface of the tumor showed a unilocular cyst with partially hypertrophic wall. Histopathological examination revealed a cystic tumor lined with heterotopic gastric and duodenal mucosa, with pancreatic tissue in the muscularis propria. In addition, evidence of bleeding from the gastric mucosa was observed in the cystic tumor. External secretion from these tissues could have triggered the hemorrhage and expanded the tumor, possibly resulting in the back pain.
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We examined the antitumor effect and safety of the adenovirus-mediated expression of antisense K-ras RNA in two peritoneal dissemination models of pancreatic cancer. First, we found that the infection of an adenovirus vector expressing antisense human K-ras RNA (AxCA-AS) induced significant apoptosis in vitro in human pancreatic cancer cells with K-ras mutation. Second, the intraperitoneal (ip) injection of AxCA-AS effectively suppressed the growth of human pancreatic cancer cells in the peritoneal cavity of nude mice. Third, in the hamster syngeneic peritoneal dissemination model, the ip injection of an adenovirus expressing antisense hamster K-ras RNA significantly suppressed the peritoneal growth of hamster pancreatic cancer cells, and no significant systemic toxicity was observed in the treated hamsters. This study suggests a feasibility of the development of a therapeutic strategy against pancreatic cancer based on the adenovirus-mediated transduction of an antisense K-ras construct.
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OGG1 protein has an ability to suppress mutagenesis induced by 8-hydroxyguanine (8OHG), an oxidatively damaged promutagenic base. Here, the mutation suppressive ability was compared between two common polymorphic OGG1 proteins, OGG1-Ser326 and OGG1-Cys326, using a supF forward mutation assay employing an 8OHG-containing plasmid. Polymorphic OGG1 proteins were exogenously expressed by adenoviral transduction in H1299 human lung cancer cells, in which endogenous OGG1 protein was undetectable by western blot analysis. Mutations by 8OHG were more efficiently suppressed in OGG1-Ser326 transduced cells than OGG1-Cys326 transduced cells. The results indicated that OGG1-Cys326 has a lower ability to prevent mutagenesis by 8OHG than OGG1-Ser326 in vivo in human cells; supporting the results of recent association studies that OGG1-Cys326 is a risk allele for several types of human cancers.
Interferon alpha (IFN-alpha) is used worldwide for the treatment of a variety of cancers. For pancreatic cancer, recent clinical trials using IFN-alpha in combination with standard chemotherapeutic drugs showed some antitumor activity of the cytokine, but the effect was not significant enough to enlist pancreatic cancer as a clinically effective target of IFN-alpha. In general, an improved therapeutic effect and safety are expected for cytokine therapy when given in a gene therapy context, because the technology would allow increased local concentrations of this cytokine in the target sites. In this study, we first examined the antiproliferative effect of IFN-alpha gene transduction into pancreatic cancer cells. The expression of IFN-alpha effectively induced growth suppression and cell death in pancreatic cancer cells, an effect which appeared to be more prominent when compared with other types of cancers and normal cells. Another strategy we have been developing for pancreatic cancer targets its characteristic genetic aberration, K-ras point mutation, and we reported that the expression of antisense K-ras RNA significantly suppressed the growth of pancreatic cancer cells. When these two gene therapy strategies are combined, the expression of antisense K-ras RNA significantly enhanced IFN-alpha-induced cell death (1.3- to 3.5-fold), and suppressed subcutaneous growth of pancreatic cancer cells in mice. Because the 2',5'-oligoadenylate synthetase/RNase L pathway, which is regulated by IFN and induces apoptosis of cells, is activated by double-strand RNA, it is plausible that the double-strand RNA formed by antisense and endogenous K-ras RNA enhanced the antitumor activity of IFN-alpha. This study suggested that the combination of IFN-alpha and antisense K-ras RNA is a promising gene therapy strategy against pancreatic cancer.
Pancreatic cancer is the fifth leading cause of cancer-related mortality in Japan, with an estimated annual incidence rate of approximately 20,000 cases. Even in patients with resectable disease, the long-term outcome remains unsatisfactory due to early recurrence after resection. However, surgical resection has offered the only curative strategy for pancreatic cancer. Currently available chemotherapeutic agents have little impact on survival, although the development of gemcitabine has renewed interest in clinical research for pancreatic cancer. To further improve the prognosis of patients with pancreatic cancer, the development of more effective nonsurgical treatment is essential. Studies to identify more effective treatments, such as chemotherapy, interventional therapy and gene therapy, are ongoing in Japan. The expanding understanding of molecular and genetic biology should facilitate research to develop novel molecular-targeted agents and to establish individualized therapy regimens for this disease.
Pancreatic cancer remains one of the most difficult cancers to treat. Its high propensity to infiltrate and metastasize early from a small primary focus necessitates development of a new therapy which can track down the disseminated cancer cells in vivo. Gene therapy may offer new opportunities for a variety of targeting strategies, and we review here some of our work related to the development of targeted gene therapy: 1) Targeting by specific molecular abnormality: Many pancreatic cancer cells show "addiction" to K-ras mutation, while normal cells appear resistant to suppression of K-ras-mediated signaling by antisense K-ras RNA expression adenoviral vector. 2) Targeting by in vivo tumor characteristics: In a peritoneal dissemination model, intraperitoneal lipofection/polyfection can deliver and express transgenes highly preferentially in tumor nodules. 3) Targeting by vector: An efficient protocol for construction of an adenovirus expression vector library has been developed, which will enable a direct functional selection of fiber knob-modified targeting vector species for given cells. 4) Targeting by tumor immunity: Several cytokines not only induce direct cytotoxicity, but are also expected to activate specific immunity to achieve targeted suppression of cancer cells in vivo. Unlike parenteral administration of short-lived recombinant interferon protein, local interferon gene transfer can provide a target tissue-restricted distribution and sustained expression, which may improve the efficacy/safety balance of cytokine therapy. Cancer gene therapy development is, in general, at the stage of proof of principles and safety. However, it is an art of integrated science. The recent rapid progress of related sciences and technologies will expand the potential and consolidate the clinical reality of gene therapy.
The point mutations of the K-ras gene occur in as high as 70-90% of the cases with adenocarcinoma of the pancreas and apparently represent one of the key and early events in the carcinogenesis. However, the specific influence of the K-ras activation on global gene expression profiles in pancreatic cancer cells has not been elucidated. In this study, to promote elucidation of the K-ras-triggered molecular cascade(s) in pancreatic cancer, four pancreatic cancer cell lines with K-ras point mutations were infected with an adenovirus vector expressing an antisense K-ras RNA (AxCA-AS), and the change of gene expression was analyzed by oligonucleotide-based microarrays containing 12,626 genes. Among the genes showing more than 2-fold differences in the expression levels between the control- and antisense-K-ras-transduced cells, 7 genes were commonly up-regulated and 4 genes were commonly down-regulated in three or all of the four pancreatic cancer cell lines transduced with AxCA-AS. The altered gene expression levels observed by microarrays were confirmed by real-time RT-PCR methods. Then, the expression of the 4 down-regulated genes was examined in the untransduced surgical specimens of pancreatic cancer. The G-protein coupled receptor RE2 and phenylethanolamine N-methyltransferase had negligible expression levels in all pancreatic cancers, whereas the syntaxin 1A and p120 catenin isoform were significantly up-regulated in pancreatic cancers containing K-ras mutations compared with a pancreatic cancer with wild type K-ras gene. The transcriptional regulation of those genes may be a part of the molecular cascades triggered by K-ras activation leading to the development and/or progression of pancreatic cancer.
Krüppel-like factors (KLFs) are key transcriptional regulators of cell differentiation and proliferation. Among the KLF family, the expression of KLF4 (GKLF) and KLF5 (IKLF) is highly restricted in the epithelial cells of several organs such as the gut and skin, and it has been reported that these epithelial-type KLF genes may be involved in colon carcinogenesis. Recently we found that Klf4 and Klf5 genes were significantly expressed in the developmental bladder epithelium of mice as well. Therefore, in this report we studied the involvement of the KLF4 and KLF5 genes in bladder carcinogenesis. First, we analyzed the expression of KLF4 and KLF5 in a variety of human bladder cancer cell lines and surgical specimens by RNA blot and in situ hybridization analyses. Both genes were highly expressed in the normal bladder epithelium, whereas KLF4, but not KLF5, was frequently downregulated in bladder cancer cell lines and cancer tissues. We then transduced the KLF4 and KLF5 genes into the bladder cancer cell lines using adenoviral vectors to examine the biological activities of the genes on those cells. The transduction of KLF4, but not KLF5, suppressed cell growth and induced apoptosis. Our study suggests that inactivation of KLF4 is one of the frequent steps towards bladder carcinogenesis.
Recently we reported that on-site interferon (IFN)-alpha production in the liver using an adenovirus vector can achieve a substantial confinement of IFN-alpha in the target organ and can improve liver fibrosis in a rat liver cirrhosis model. However, the major therapeutic effect of IFN for hepatitis C virus (HCV)-associated liver diseases is its antiviral effect on HCV. As a prelude to the in vivo HCV infection experiment using a primate animal model, here we examined the antiviral effect of IFN-alpha gene transfer into HCV-positive hepatocytes in vitro. The non-neoplastic human hepatocyte cell line PH5CH8 was inoculated with HCV-positive serum. Successful in vitro HCV replication and thus the validity of this model was confirmed by a strong selection for HCV variants determined by sequence analysis of the hypervariable region and an increase of HCV RNA estimated by real time TaqMan RT-PCR. One day after the inoculation of HCV, PH5CH8 cells were infected with adenoviral vectors encoding human IFN-alpha cDNA. HCV completely disappeared 9 days after the adenoviral infection, which is linked to the increase of 2('),5(')-oligoadenylate synthetase activity, suggesting that IFN-alpha produced by gene transfer effectively inhibits HCV replication in hepatocytes. This study supports the development of IFN-alpha gene therapy for HCV-associated liver diseases.
Androgen ablation has been the standard treatment for metastasized prostate cancer. In most cases, however, prostate cancer cells eventually lose androgen dependency and become refractory to the conventional endocrine therapy. Androgen-independent prostate cancer is characterized by a heterogeneous loss of androgen receptor (AR) expression among tumor cells. Prostate-specific promoters such as prostate-specific antigen and rat probasin (rPB) promoters have been examined in the development of gene therapy targeted to prostate cancer. However, those promoters require binding of the androgen-AR complex to the androgen-response element and are active only in the androgen-dependent prostate cancer cell lines and not in the androgen-independent cell lines. To target transgene expression in androgen-independent prostate cancer, we designed a prostate-specific promoter that is activated by the retinoids-retinoid receptor complex instead of the androgen-AR complex. The modified rPB promoters expressed transgenes in response to retinoid in both androgen-dependent and androgen-independent prostate cancer cells and not in other cancer cell lines or in human normal cells, in vitro and in vivo. Furthermore, the combination of retinoid treatment and adenovirus-mediated gene transfer of the modified rPB-driven HSV-tk gene resulted in a significant growth suppression of the androgen-independent prostate cancer cells in the presence of the prodrug ganciclovir. This study suggests that tailoring of the hormone-responsive elements may offer a new therapeutic opportunity against the hormone-refractory stage of prostate cancer.
cDNA expression cloning is a powerful method for the identification of genes that are able to confer a selectable phenotype on specific cell types. An adenovirus vector is characterized by several advantages over plasmid DNA and retroviral vector-mediated gene transfer, such as broad host range and high infectivity. However, an expression cloning protocol using the adenovirus vector has not been reported. We describe here a simple and efficient method for constructing adenovirus cDNA expression libraries based on Cre-lox-mediated in vitro recombination between adenoviral shuttle plasmid cDNA libraries and adenoviral genomic DNA tagged with terminal protein. In a model experiment, EGFP clones present at the frequency of 0.003% in the shuttle plasmid library could be efficiently converted to adenoviral vector in a 6-cm dish under optimized conditions, indicating that high-complexity libraries harboring low-abundance cDNAs can be produced. The efficiency of this system was demonstrated by the isolation of cDNA for CD2 (frequency less than 1 in 0.3 x 10(4) transcripts in T cells) from the human T cells. This effective and versatile method can facilitate the functional identification of genes for a variety of purposes.
BACKGROUND: Allogeneic chimerism has been established in graft-accepting recipients and the donor cells in the host may act in a major way to facilitate the induction of tolerance. In this study, we examined the effects of allogeneic chimerism after injecting donor bone marrow cells (BMCs) mixed with splenocytes (SPLCs) to the sublethally conditioned recipients. METHODS: In BALB/c(H-2(d)) to B6(H-2(b)) combination, B6 recipients were irradiated at 7.5 Gy and were injected a mixture of donor BMCs and SPLCs intravenously. On day 90 after injection, the degree of chimerism in peripheral blood lymphocytes (PBL) and in the splenocytes was checked by flow cytometry. RESULTS: In groups which were injected varying BMCs, when > 45 x 10(6) BMCs were injected into B6, a large percentage of donor cells were detected in PBL and in the spleen. In contrast, when < 30 x 10(6) BMCs were injected into B6, only a small percentage of donor cells were detected. In the groups which were injected 3 x 10(6) BMCs with varying SPLCs, when > 10 x 10(6) SPLCs were added, a large percentage of donor cells were detected in PBL and SPLCs, but a small percentage of donor cells were detected with the addition of < 3 x 10(6) SPLCs. A high percentage of chimeric mice showed donor specific tolerance in vitro, mixed lymphocyte responses, and in vivo, skin grafting. In contrast, only a small percentage of chimeric mice showed no donor specific tolerance by skin grafting. CONCLUSION: These findings suggested that even a low dose of BMCs can establish a state of allogeneic chimerism and donor specific tolerance if combined with SPLCs.