TMEM132C rs7296262 Single-Nucleotide Polymorphism Is Significantly Associated with Nausea Induced by Opioids Administered for Cancer Pain and Postoperative Pain.

Opioids are almost mandatorily used for analgesia for cancer pain and postoperative pain. Opioid analgesics commonly induce nausea as a side effect. However, the genetic factors involved are still mostly unknown. To clarify the genetic background of individual differences in the occurrence of nausea during opioid administration, the incidence of nausea was investigated in 331 patients (Higashi-Sapporo Hospital [HS] group) who received morphine chronically for cancer pain treatment and in 2021 patients (Cancer Institute Hospital [CIH] group) who underwent elective surgery under general anesthesia. We conducted a genome-wide association study of nausea in HS samples. Among the top 20 candidate single-nucleotide polymorphisms (SNPs), we focused on the TMEM132C rs7296262 SNP, which has been reportedly associated with psychiatric disorders. The rs7296262 SNP was significantly associated with nausea in both the HS and CIH groups (TT+TC vs. CC; HS group, p = 0.0001; CIH group, p = 0.0064). The distribution of nausea-prone genotypes for the rs7296262 SNP was reversed between HS and CIH groups. These results suggest that the TMEM132C rs7296262 SNP is significantly associated with nausea during opioid use, and the effect of the SNP genotype on nausea is reversed between chronic and acute phases of opioid use.

Peptide vaccinations elicited strong immune responses that were reboosted by anti-PD1 therapy in a patient with myxofibrosarcoma.

Peptide-based immunotherapy does not usually elicit strong immunological and clinical responses in patients with end-stage cancer, including sarcoma. Here we report a myxofibrosarcoma patient who showed a strong clinical response to peptide vaccinations and whose immune responses were reboosted by anti-PD1 therapy combined with peptide vaccinations. The 46-year-old man showed a strong response to the peptide vaccinations (papillomavirus binding factor peptide, survivin-2B peptide, incomplete Freund's adjuvant, and polyethylene glycol-conjugated interferon-alpha 2a) and subsequent wide necrosis and massive infiltration of CD8+ T cells in a recurrent tumor. The patient's immune responses weakened after surgical resection; however, they were reboosted following the administration of nivolumab combined with peptide vaccinations. Thus, anti-PD1 therapy combined with peptide vaccinations might be beneficial, as suggested by the observations in this sarcoma patient.

Development of a T-cell receptor multimer with high avidity for detecting a naturally presented tumor-associated antigen on osteosarcoma cells.

For efficacy of peptide vaccination immunotherapy for patients with cancer, endogenous expression of the target peptide/human leukocyte antigen (HLA) on cancer cells is required. However, it is difficult to evaluate the expression status of a peptide/HLA complex because of the lack of a soluble T-cell receptor (TCR) that reacts with tumor-associated antigen (TAA) with high avidity. In the present study, we developed two soluble TCR-multimers that were each directed to TAA, survivin-2B (SVN-2B) and PBF in the context of HLA-A24 (SVN-2B TCR-multimer and PBF TCR-multimer, respectively), from CTL clones that were established from peptide-vaccinated patients. Both TCR multimers could recognize cognate peptide-pulsed antigen-presenting cells, C1R-A24 cells, in a CD8-independent method. Moreover, the PBF TCR-multimer successfully recognized a PBF peptide naturally presented on HLA-A24+ PBF+ osteosarcoma cells. Taken together, the results indicated that a TCR-multimer might be useful for detection of a TAA-derived peptide presented by HLA in patients receiving immunotherapy.

Clinical factors associated with the therapeutic outcome of chemotherapy in very elderly cancer patients.

BACKGROUND: The purpose of this study was to detect background factors that might be associated with the therapeutic and curative outcome of chemotherapy in elderly cancer patients aged over 75 years. METHODS: A retrospective study was conducted for elderly cancer patients aged over 75 years who had received more than 2 courses of chemotherapy at our hospital. We analyzed the relationships between RECIST outcome and background factors, such as age, sex, clinical TNM stage, pre-treatment history, ECOG performance status, serum albumin, and Charlson comorbidity index using logistic regression analysis. RESULTS: A total of 103 cancer patients aged over 75 years were analyzed in this study, including 28 with hematological neoplasia, 36 with gastrointestinal tract cancers, 25 with breast cancers, and 14 with other malignancies originating in various tissues. Seventy-one patients (69.1%) had a positive clinical outcome including RECIST CR (complete response), PR (partial response) and SD (stable disease). Multivariate analysis showed that a high serum albumin level of more than 3.5 g/dl and a Charlson comorbidity index score of less than 2 points were positively correlated with a favorable therapeutic outcome. CONCLUSIONS: The results of the current study suggested that serum albumin level and comorbidity index are the principal clinical factors affecting therapeutic outcomes in elderly cancer patients receiving chemotherapy. In the future, these factors may make chemotherapy adaptations, continuity, and effectiveness easier to predict than GA screening.

A new once-a-day fentanyl citrate patch (Fentos Tape) could be a new treatment option in patients with end-of-dose failure using a 72-h transdermal fentanyl matrix patch.

PURPOSE: The recommended dosing interval for transdermal fentanyl is every 72 h. However, some patients will have "end-of-dose failure," which may be seen as an increase of episodes of severe pain flares at the third day after application of the patch. A new once-a-day fentanyl patch was developed in Japan since 2010. This study aimed to assess the efficacy of the once-a-day fentanyl citrate patch for patients with cancer-related pain receiving the 72-h transdermal fentanyl not lasting 72 h. METHODS: We performed a cross-sectional retrospective analysis of 445 inpatients with the 72-h transdermal fentanyl at Higashi Sapporo Hospital. We could switch to the once-a-day fentanyl citrate patch if patients reported inadequate pain relief beyond 48 h after application of the 72-h transdermal fentanyl. Patients recorded baseline scores for background pain intensity (PI) and the frequency of use of daily rescue medication for breakthrough cancer pain (BTcP). RESULTS: Of all patients, 10.1% showed the increase in PI of 30% or more baseline PI on the third day after application of the 72-h transdermal fentanyl. Of patients, 84.4% were converted from equivalent dose of the 72-h transdermal fentanyl to the once-a-day fentanyl citrate patch. On the third day after switching, 60.5% of patients showed a reduction of more than 30% from baseline PI. Switching to the once-a-day fentanyl citrate patch significantly reduced the mean frequency of daily rescue dose for BTcP. CONCLUSIONS: A once-a-day fentanyl citrate patch provided stable pain control. Its use may be considered as the dominant strategy for patients receiving a 72-h transdermal fentanyl not lasting 72 h.

Effect of duloxetine in Japanese patients with chemotherapy-induced peripheral neuropathy: a pilot randomized trial.

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is difficult to manage. A phase III trial conducted in the United States demonstrated that duloxetine was effective for CIPN caused by taxane and platinum-based chemotherapy. No randomized trial of duloxetine for CIPN has been conducted in Japan. METHODS: In this open-label, randomized, crossover study, eligible patients were randomized to Group A or Group B. Group A received duloxetine 20 mg/day orally for the first week and 40 mg/day for the next 3 weeks. Group B received vitamin B12 (VB12) 1.5 mg/day orally for 4 weeks. After a 2- to 4-week washout period, treatment was crossed over for another 4 weeks. The severity of numbness and pain was assessed using a visual analog scale (VAS). RESULTS: Thirty-four patients were enrolled. Obvious decreases in the mean VAS scores for numbness and pain were observed for the periods of duloxetine administration. Significant differences were observed between the duloxetine-first (Group A) and the VB12-first (Group B) groups with respect to numbness (p = 0.03) and pain (p = 0.04) at 4 weeks after administration. Fatigue was observed in six of the 34 participants (17.6 %). CONCLUSIONS: Our data suggests that duloxetine has a beneficial effect on CIPN caused by oxaliplatin, paclitaxel, vincristine, or bortezomib in Japanese patients.

Effectiveness of multidisciplinary team conference on decision-making surrounding the application of continuous deep sedation for terminally ill cancer patients.

OBJECTIVE: Continuous deep sedation (CDS) is a way to reduce conscious experience of symptoms of severe suffering in terminally ill cancer patients. However, there is wide variation in the frequency of its reported. So we conducted a retrospective analysis to assess the prevalence and features of CDS in our palliative care unit (PCU). METHODS: We performed a systemic retrospective analysis of the medical and nursing records of all 1581 cancer patients who died at the PCU at Higashi Sapporo Hospital between April 2005 and August 2011. Continuous deep sedation can only be administered safely and appropriately when a multidisciplinary team is involved in the decision-making process. Prior to administration of CDS, a multidisciplinary team conference (MDTC) was held with respect to all the patients considered for CDS by an attending physician. The main outcome measures were the frequency and characteristics of CDS (patient background, all target symptoms, medications used for sedation, duration, family's satisfaction, and distress). We mailed anonymous questionnaires to bereaved families in August 2011. RESULTS: Of 1581 deceased patients, 22 (1.39%) had received CDS. Physical exhaustion 8 (36.4%), dyspnea 7 (31.8%), and pain 5 (22.7%) were the most frequently mentioned indications. Continuous deep sedation had a duration of less than 1 week in 17 (77.3%). Six patients (0.38%) did not meet the appropriate criteria for CDS according to the MDTC and so did not receive it. Although bereaved families were generally comfortable with the practice of CDS, some expressed a high level of emotional distress. SIGNIFICANCE OF RESULTS: Our results indicate that the prevalence of CDS will be decreased when it is carried out solely for appropriate indications. Continuity of teamwork, good coordination, exchange of information, and communication between the various care providers are essential. A lack of any of these may lead to inadequate assessment, information discrepancies, and unrest.

B-cell lymphoma developing de novo hepatitis B after salvage therapies including rituximab through seroconversion of surface antibody.

The patient was a 73-year-old woman. At 63 years of age, she had developed follicular lymphoma that showed a complete response to R-CHOP therapy. Over the subsequent 8 years, she experienced 4 relapses and was administered rituximab monotherapy once, combined rituximab-fludarabine therapy twice, and CHASE-R therapy once, achieving a complete response each time. Before her first therapy, hepatitis B virus (HBV) surface antigen was negative, while hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody were not measured. Later, before her second salvage therapy, anti-HBs was negative, but then changed to positive before her third salvage therapy. HBV-DNA was negative before CHASE-R therapy. At 16 months after completing the CHASE-R therapy, she developed hepatitis and HBV-DNA had changed to positive. Hepatitis did not become fulminant and entecavir administration was effective. It was surmised that HBV had resolved, but she became negative for anti-HBs following the rituximab-containing chemotherapy. Therefore, this is a rare case in which de novo hepatitis developed after the final chemotherapy. The prognosis of patients with de novo hepatitis accompanying treatment of B-cell lymphoma is poor. In those who undergo lymphoma salvage therapy, the risk for and clinical course of HBV reactivation might differ from those of treatment-naïve patients.

Cytotoxic T lymphocytes efficiently recognize human colon cancer stem-like cells.

Cancer stem-like cells (CSCs) and tumor-initiating cells (TICs) are a small population of cancer cells that share three properties: tumor initiating ability, self-renewal, and differentiation. These properties suggest that CSCs/TICs are essential for tumor maintenance, recurrence, and distant metastasis. Here, we show that cytotoxic T lymphocytes (CTLs) specific for the tumor-associated antigen CEP55 can efficiently recognize colon CSCs/TICs both in vitro and in vivo. Using Hoechst 33342 dye staining, we isolated CSCs/TICs as side population (SP) cells from colon cancer cell lines SW480, HT29, and HCT15. The SP cells expressed high levels of the stem cell markers SOX2, POU5F1, LGR5, and ALDH1A1 and showed resistance to chemotherapeutic agents such as irinotecan or etoposide.To evaluate the susceptibility of SP cells to CTLs, we used CTL clone 41, which is specific for the CEP55-derived antigenic peptide Cep55/c10orf3_193 (10) (VYVKGLLAKI). The SP cells expressed HLA class I and CEP55 at the same level as the main population cells. The SP cells were susceptible to CTL clone 41 at the same level as main population cells. Furthermore, adoptive transfer of CTL clone 41 inhibited tumor growth of SW480 SP cells in vivo. These observations suggest that Cep55/c10orf3_193(10) peptide-based cancer vaccine therapy or adoptive cell transfer of the CTL clone is a possible approach for targeting chemotherapy-resistant colon CSCs/TICs.

Essential role of protein kinase C zeta in transducing a motility signal induced by superoxide and a chemotactic peptide, fMLP.

Under various pathological conditions, including infection, malignancy, and autoimmune diseases, tissues are incessantly exposed to reactive oxygen species produced by infiltrating inflammatory cells. We show augmentation of motility associated with morphological changes of human squamous carcinoma SASH1 cells, human peripheral monocytes (hPMs), and murine macrophage-like cell line J774.1 by superoxide stimulation. We also disclose that motility of hPMs and J774.1 induced by a chemotactic peptide (N-formyl-methionyl-leucyl-phenylalanine [fMLP]) was inhibited by superoxide dismutase or N-acetylcystein, indicating stimulation of motility by superoxide generated by fMLP stimulation. In these cells, protein kinase C (PKC) zeta was activated to phosphorylate RhoGDI-1, which liberated RhoGTPases, leading to their activation. These events were inhibited by dominant-negative PKCzeta in SASH1 cells, myristoylated PKCzeta peptides in hPMs and J774.1, or a specific inhibitor of RhoGTPase in SASH1, hPMs, and J774.1. These results suggest a new approach for manipulation of inflammation as well as tumor cell invasion by targeting this novel signaling pathway.

Genome-Wide Association Study Identifies Candidate Loci Associated with Opioid Analgesic Requirements in the Treatment of Cancer Pain.

Considerable individual differences have been widely observed in the sensitivity to opioids. We conducted a genome-wide association study (GWAS) in patients with cancer pain to identify potential candidate single-nucleotide polymorphisms (SNPs) that contribute to individual differences in opioid analgesic requirements in pain treatment by utilizing whole-genome genotyping arrays with more than 650,000 markers. The subjects in the GWAS were 428 patients who provided written informed consent and underwent treatment for pain with opioid analgesics in a palliative care unit at Higashi-Sapporo Hospital. The GWAS showed two intronic SNPs, rs1283671 and rs1283720, in the ANGPT1 gene that encodes a secreted glycoprotein that belongs to the angiopoietin family. These two SNPs were strongly associated with average daily opioid requirements for the treatment of pain in both the additive and recessive models (p < 5.0000 × 10−8). Several other SNPs were also significantly associated with the phenotype. In the gene-based analysis, the association was significant for the SLC2A14 gene in the additive model. These results indicate that these SNPs could serve as markers that predict the efficacy of opioid analgesics in cancer pain treatment. Our findings may provide valuable information for achieving satisfactory pain control and open new avenues for personalized pain treatment.

The feasibility of Cep55/c10orf3 derived peptide vaccine therapy for colorectal carcinoma.

In our previous study, we demonstrated that a peptide derived from the novel centrosome residing protein Cep55/c10orf3 can be targeted by the cytotoxic T lymphocytes (CTLs) in peripheral blood mononuclear cells (PBMCs) of breast carcinoma patients. In this report, we evaluated the feasibility of cancer immunotherapy using Cep55/c10orf3 peptide for colorectal carcinoma (CRC). To evaluate the expression of Cep55/c10orf3 in CRC tissues, we performed immunohistochemical staining of using anti-Cep55/c10orf3 monoclonal antibody. Sixty-three percent cases showed weak positive for Cep55/c10orf3 in total 70 CRC cases. The Cep55/c10orf3 expression intention was collated with high histological grade of CRC. Thus, we hypothesized that Cep55/c10orf3 can also be the target of CTLs in CRC cases. We generated CTLs from PBMCs of human leukocyte antigen (HLA)-A24-positive colorectal carcinoma patients using HLA-A24-restricted Cep55/c10orf3 peptides. Two of 6 colorectal cancer patients were reactive for the Cep55/c10orf3_193(10) peptide, which was the only immunogenic peptide in breast carcinoma patients. CTL clone specific for Cep55/c10orf3_193(10) recognized and lysed HLA-A24 (+) and Cep55/c10orf3 (+) colorectal carcinoma cell lines. In addition, 1 of 6 colorectal carcinoma patients was reactive for the Cep55/c10orf3_402(11) and Cep55/c10orf3_283(12) peptides, but not for Cep55/c10orf3_193(10) with the ELISPOT assay. These observations suggest that the antigenic peptide repertoire presented by HLA-A24 in colorectal carcinoma might be different from that in breast carcinoma. Thus, these peptide vaccination peptide mixture of Cep55/c10orf3_193(10), Cep55/c10orf3_402(11) and Cep55/c10orf3_283(12) might be more effective than a single peptide in the treatment of colorectal carcinoma patients.

[Successful induction of complete remission by gemtuzumab ozogamicin following chemotherapy in three patients with relapsed or refractory acute myeloid leukemia].

The institutional review board of our hospital approved FLAG-MG therapy (G-CSF 300 microg day 1-6, fludarabin 30 mg/m(2) day 2-6, Ara-C 1 g/m(2) day 2-6, mitoxantrone 5 mg/m(2) day 2-4, gemtuzumab ozogamicin 3 mg/m(2) day 9) for relapsed or refractory elderly acute myeloid leukemia patients. We conducted this therapy for two refractory patients aged 56 and 63 and one relapsed 58-year-old patient. All three patients were induced complete remission after FLAG-MG therapy without serious complications.

The Antigen ASB4 on Cancer Stem Cells Serves as a Target for CTL Immunotherapy of Colorectal Cancer.

Colorectal cancer consists of a small number of cancer stem cells (CSC) and many non-CSCs. Although rare in number, CSCs are a target for cancer therapy, because they survive conventional chemo- and radiotherapies and perpetuate tumor formation in vivo In this study, we conducted an HLA ligandome analysis to survey HLA-A24 peptides displayed by CSCs and non-CSCs of colorectal cancer. The analysis identified an antigen, ASB4, which was processed and presented by a CSC subset but not by non-CSCs. The ASB4 gene was expressed in CSCs of colorectal cancer, but not in cells that had differentiated into non-CSCs. Because ASB4 was not expressed by normal tissues, its peptide epitope elicited CD8+ cytotoxic T-cell (CTL) responses, which lysed CSCs of colorectal cancer and left non-CSCs intact. Therefore, ASB4 is a tumor-associated antigen that can elicit CTL responses specific to CSCs and can discriminate between two cellular subsets of colorectal cancer. Adoptively transferred CTLs specific for the CSC antigen ASB4 could infiltrate implanted colorectal cancer cell tumors and effectively prevented tumor growth in a mouse model. As the cancer cells implanted in these mice contained very few CSCs, the elimination of a CSC subset could be the condition necessary and sufficient to control tumor formation in vivo These results suggest that CTL-based immunotherapies against colorectal CSCs might be useful for preventing relapses. Cancer Immunol Res; 6(3); 358-69. ©2018 AACR.

[Reappearance of t(12;17)-positive primary myelofibrosis following Ph+ CML cell reduction by imatinib].

A 67-years old woman was referred to our hospital in October 1992 with thrombocytopenia and splenomegaly. A bone marrow biopsy revealed decreased cellularity, with moderately increased reticulin fibrosis and discrete dysmorphic megakaryocytes but no signs of dysplasia in the erythroid or the myeloid lineages. The karyotype of the bone marrow cells was t(12;17) (q24;q11). She was diagnosed as having agnogenic myeloid metaplasia. The patient received only blood transfusions until November 1998 when leukocytosis with immature cells started to appear. The bone marrow aspiration analysis showed increased cellularity and chromosomal analysis demonstrated the presence of t(9;22) (q34;q11) without any t(12;17) (q24;q11) abnormality. Because IFN therapy and oral administration of hydroxyurea did not show any cytological effect, administration of imatinib mesylate was started from December 2001. The Ph-positive cells as demonstrated by the FISH method had decreased to 7% by April 2003. But the t(12;17)(q24;q11) positive clones, which were observed on the first admission, again appeared in the peripheral blood, whereas Ph clones were detected in only one out of 24 cells examined. During the course of treatment with imatinib mesylate for chronic myelogenous leukemia which developed from agnogenic myeloid metaplasia accompanied with t(12;17)(q24;q11) translocation, the co-existence of two clones derived from, possibly, stem cells was identified.

[Acute myelogenous leukemia with multilineage myelodysplasia, positive direct Coombs test, and elevated levels of platelet-associated IgG].

A 75-year-old man was admitted to our hospital in October, 2005 for examination of pre-diagnosed pancytopenia. His bone marrow showed myeloid dysplasia, and 30.4% of the nucleated cells were blasts. Our diagnosis was acute myelogenous leukemia with multilineage myelodysplasia (AML with MLD; WHO classification). A direct Coombs test proved positive, and the platelet-associated IgG (PA-IgG) level was elevated. After treatment with CAG (Ara-C + ACR + G-CSF), complete remission was obtained, showing negative on the direct Coombs test with PA-IgG levels returned to normal. The patient subsequently relapsed, testing positive on the direct Coombs test and experiencing a re-elevation of PA-IgG levels. We report here a first case of AML with MLD, direct Coombs test and PA-IgG assay.

[T-cell rich B-cell lymphoma associated with neutrophilia and thrombocytosis].

A 49-year-old man was admitted with high-grade fever, night sweating and cervical lymphadenopathy in September 2005. On examination, both neutrophilia and thrombocytosis were noted in the peripheral blood, a bone marrow examination revealed marked both myeloid and megakaryocytic hyperplasia. The sera obtained at initial presentation showed an elevated levels of granulocyte-colony stimulating factor (G-CSF) and interleukin-6 (IL-6). A pathologic diagnosis of T-cell rich B-cell lymphoma was made based on an inguinal lymph node biopsy. Following treatment with CHOP accompanied by rituximab (R-CHOP), both the neutrophilia and thrombocytosis subsided after 3 courses of R-CHOP, resulting in a complete remission after 4 courses of chemotherapy. Neutrophilia, thrombocytosis and T-cell rich B-cell lymphoma in this patient were considerably ameliorated with chemotherapy. We report here a patient with T-cell rich B-cell lymphoma associated with both neutrophilia and thrombocytosis, suggesting that the lymphoma triggered both myeloid and megakaryocytic hyperplasia.

Collusions Between Patients and Clinicians in End-of-Life Care: Why Clarity Matters.

Collusion, an unconscious dynamic between patients and clinicians, may provoke strong emotions, unreflected behaviors, and a negative impact on care. Collusions, prevalent in the health care setting, are triggered by situations which signify an unresolved psychological issue relevant for both, patient and clinician. After an introductory definition of collusion, two archetypal situations of collusion-based on material from a regular supervision of a palliative care specialist by a liaison psychiatrist-and means of working through collusion are presented. The theoretical framework of collusion is then described and the conceptual shortcomings of the palliative care literature in this respect discussed, justifying the call for more clarity. Finally, cultural aspects and societal injunctions on the dying, contributing to the development of collusion in end-of-life care, are discussed.

Induction of PIG3 and NOXA through acetylation of p53 at 320 and 373 lysine residues as a mechanism for apoptotic cell death by histone deacetylase inhibitors.

Two controversial issues regarding p53 are whether it is involved in apoptosis induction of tumor cells by a histone deacetylase (HDAC) inhibitor and, given that p53 is indeed involved, which genes of acetylated p53 targets are responsible for giving rise to apoptotic death. We, in the present study, first confirmed that some substantial extent of apoptotic cell death was seen when p53-deficient cells (KATO-III) were transfected with wild-type p53 and treated with sodium butyrate (SB) or trichostatin A. By Western blotting, using specific antibodies, we then demonstrated that residues 320, 373, and 382 lysines of p53 were acetylated in KATO-III cells transfected with wild-type p53 (KATO-III/p53) treated with a HDAC inhibitor. However, as revealed by terminal deoxynucleotidyl transferase-mediated nick end labeling staining, only those KATO-III cells transfected with K320R p53 or K373R p53 became insensitive to the HDAC inhibitor, suggesting that these two residues of p53 may be essential for HDAC inhibitor-induced apoptosis, whereas others such as K382R p53 may not. Furthermore, reverse transcription-PCR demonstrated that among various p53-related proapoptotic genes, expression of PIG3 and NOXA were clearly enhanced by SB treatment in KATO-III/p53 cells but not in KATO-III/K320R or KATO-III/K373R cells. Finally, we revealed that apoptosis could be evoked by SB even in cells where p53 mutations occur at residues other than 320 lysine or 373 lysine (TMK-1 and HSC-39 cells) and that this apoptosis was significantly, although not totally, suppressed by the anti-p53 antisense. It was, therefore, concluded that acetylation of the p53 molecule at residues 320 and 373, giving rise to up-regulation of PIG3 and NOXA, is one of the mechanisms for induction of apoptosis by HDAC inhibitors in cancer cells.

Olfactory Receptor Family 7 Subfamily C Member 1 Is a Novel Marker of Colon Cancer-Initiating Cells and Is a Potent Target of Immunotherapy.

PURPOSE: Cancer-initiating cells (CICs) are thought to be essential for tumor maintenance, recurrence, and distant metastasis, and they are therefore reasonable targets for cancer therapy. Cancer immunotherapy is a novel approach to target cancer. In this study, we aimed to establish novel CIC-targeting immunotherapy. EXPERIMENTAL DESIGN: Colorectal cancer (CRC) CICs were isolated as side population (SP) cells. The gene expression profile of CRC CICs was analyzed by cDNA microarray and RT-PCR. Protein expression of olfactory receptor family 7 subfamily C member 1 (OR7C1) were analyzed by Western blot and immunohistochemical staining. The functions of OR7C1 were analyzed by gene overexpression and gene knockdown using siRNAs. OR7C1-positive cells were isolated by a flow cytometer and analyzed. CTLs specific for OR7C1 peptide were generated, and the antitumor effect was addressed by mice adoptive transfer model. RESULTS: OR7C1 has essential roles in the maintenance of colon CICs, and the OR7C1-positive population showed higher tumorigenicity than that of the OR7C1-negative population, indicating that OR7C1 is a novel functional marker for colon CIC. Immunohistochemical staining revealed that OR7C1 high expression was correlated with poorer prognosis in CRC patients. OR7C1-derived antigenic peptide-specific CTLs showed specific cytotoxicity for CICs, and an OR7C1-specific CTL clone showed a greater antitumor effect than did a CTL clone targeting all cancer cells in a CTL adoptive transfer mouse model. CONCLUSIONS: OR7C1 is a novel marker for colon CICs and can be a target of potent CIC-targeting immunotherapy. Clin Cancer Res; 22(13); 3298-309. ©2016 AACR.