Prognostic value of MAGEA4 in primary lung cancer depends on subcellular localization and p53 status

Melanoma antigen family A4 (MAGEA4), a cancer/testis antigen, is overexpressed and is thus an immunotherapy target in various malignant tumors, including non-small cell lung cancer. However, whether MAGEA4 induces or inhibits the apoptosis of lung cancer cells remains controversial, as is its prognostic significance, particularly since there is no reliable method with which to detect MAGEA4 specifically. In this study, we optimized assay conditions to detect MAGEA4 based on cells transiently transfected with MAGEA genes, and found that MAGEA4 was expressed in four of eight non-small cell lung cancer cell lines, and in 25.4% of clinical lung cancer specimens. We also found that MAGEA4 overexpression decreased apoptosis, as measured by the levels of cleaved caspase-3 in stably transfected 293F cells. Notably, patients with nuclear MAGEA4, but not p53 expression exhibited a significantly poorer survival than those expressing both nuclear MAGEA4 and p53. Indeed, multivariate analysis identified nuclear MAGEA4 as an independent prognostic factor (P=0.0042), albeit only in the absence of p53. In this study, to the best of our knowledge, we are the first to demonstrate that the function and prognostic value of MAGEA4 depends on its subcellular localization and on the p53 status.

Circular versus linear stapling in esophagojejunostomy after laparoscopic total gastrectomy for gastric cancer: a propensity score-matched study

PURPOSE

We used propensity score matching to compare the complication rates after laparoscopic total gastrectomy (LTG) with esophagojejunostomy (EJS) performed using a circular or a linear stapler.

METHODS

We retrospectively enrolled all patients who underwent curative LTG between November 2004 and March 2016. Patients were categorized into the circular and linear groups according to the stapler type used for the subsequent EJS. Patients in the groups were matched using the following propensity score covariates: age, sex, body mass index, American Society of Anesthesiologists physical status, extent of lymph node dissection, and Japanese Classification of Gastric Carcinoma stage. Clinicopathological characteristics and surgical outcomes were compared.

RESULTS

We identified 66 propensity score-matched pairs among 379 patients who underwent LTG. There was no significant between-group difference in the median operative time, extent of lymph node dissection, number of lymph nodes resected, rate of conversion to open surgery, or number of surgeries performed by a surgeon certified by the Japanese Society of Endoscopic Surgery. In the circular and linear groups, the rate of all complications (Clavien-Dindo [CD] classification ≥ I; 21 vs. 26%, respectively; p = 0.538), complications more severe than CD grade III (14 vs. 14%, respectively; p = 1.000), and occurrence of EJS leakage and stenosis more severe than CD grade III (5 vs. 2%, p = 0.301; 9 vs. 8%, p = 0.753, respectively) were comparable.

CONCLUSIONS

There is no difference in the postoperative complication rate related to the type of stapler used for EJS after LTG.

Clinical Implications of CD4+CD25+Foxp3+Regulatory T Cell Frequencies After CHP-MAGE-A4 Cancer Vaccination

BACKGROUND/AIM

The aim of this study was to explore whether the treatment effect or immune response to a cancer vaccine can be predicted by the percentage of CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Tregs) in peripheral blood mononuclear cells (PBMCs) after vaccination.

PATIENTS AND METHODS

Sixteen patients (9 men, 7 women; median age 61.5 years) enrolled in the CHP-MAGE-A4 cancer vaccine clinical trial who had a fixed dose (300 μg of CHP-MAGE-A4 cancer vaccine and 0.5 Klinische Einheit (KE) of OK432 and received at least four vaccinations were investigated. Safety, immune response, and clinical effects were assessed before and after the cancer vaccination.

RESULTS

Treg ratios that remained low both before and after vaccination were associated with a good prognosis, and a low Treg/CD4 lymphocyte ratio 7-weeks after the initial vaccination was correlated with a better prognosis.

CONCLUSION

The Treg ratio following vaccination appears to have some utility for predicting patient prognosis.

Serum immunoglobulin E response as a marker for unfavorable prognosis following cholesteryl pullulan-MAGE A4 vaccination

Since 2009, a cancer vaccine clinical trial was conducted with melanoma antigen gene-A4 as an immunogenic agent. The levels of IgG1, IgG2 and IgG3, which are known to be Type 1 T helper cell-associated antibodies, and the levels of IgG4 and IgE, which are known to be Type 2 T helper cell-associated antibodies, were measured and used as biomarkers for predicting therapeutic effect. The results of the present study indicated a strong positive correlation between IgG2 and IgG4, with a correlation coefficient of R=0.808 (P<0.0001). The survival time of patients in which IgE responses were induced was significantly shorter compared with the survival time of patients with no IgE induction. The results of the present study suggest that caution is required when antigen-specific IgE responses are induced during cancer vaccination therapy.

Time-dependent transition of the immunoglobulin G subclass and immunoglobulin E response in cancer patients vaccinated with cholesteryl pullulan-melanoma antigen gene-A4 nanogel

A phase I+II clinical trial of vaccination with MAGE-A4 protein complexed with cholesteryl pullulan melanoma antigen gene-A4 nanogel (CHP-MAGE-A4) is currently underway in patients with MAGE-A4-expressing cancer. In the present study, the primary phase I endpoint was to test the safety of the administration of 300 µg CHP-MAGE-A4 with and without OK-432. Another aim of the study was to clarify the details of the specific humoral immune response to vaccination. The 9 patients enrolled for phase I were vaccinated 6 times, once every 2 weeks: 3 patients with 100 µg and 3 patients with 300 µg CHP-MAGE-A4, and 3 patients with 300 µg CHP-MAGE-A4 plus 0.5 clinical units of OK-432. Toxicities were assessed using Common Terminology Criteria for Adverse Events v3.0. Clinical response was evaluated by modified Response Evaluation Criteria in Solid Tumours. Immunological monitoring of anti-MAGE-A4-specific antibodies was performed by ELISA of pre- and post-vaccination patient sera. The 6 vaccinations produced no severe adverse events. Stable disease was assessed in 4/9 patients. Anti-MAGE-A4 total immunoglobulin (Ig)G titers increased in 7/9 patients. Efficacious anti-MAGE-A4 IgG1, 2 and 3 antibody responses were observed in 7/9 patients. Among them, positive conversions to T helper 2 (Th2)-type antibody responses (IgG4 and IgE) were observed after frequent vaccination in 4/7 patients. The Th2 conversion was possibly associated with undesirable clinical observations, including progressive disease and the appearance of a new relapse lesion. The present study suggested that frequent vaccinations activated a Th2-dominant status in the cancer patients. The identification of a time-dependent IgG subclass and IgE antibody production during vaccination protocols may be a useful surrogate marker indicating a potentially undesirable change of the immunological environment for an effective antitumor immune response in cancer patients.

Clinical relevance of antigen spreading pattern induced by CHP-MAGE-A4 cancer vaccination

AIM

To investigate the antigen spreading pattern in the CHP-MAGE-A4-vaccinated patients and analyze the clinical relevance of antigen spreading pattern as a surrogate marker of patient survival.

MATERIALS & METHODS

12 patients who had been injected with 300 μg of CHP-MAGE-A4 and 0.5 Klinische Einheit of OK-432 in more than five vaccinations were analyzed.

RESULTS

Increases in the anti-MAGE-A4-specific antibody response were observed in eight patients (66.7%), compared with six patients (50%) for anti-NY-ESO-1 and five patients (41.7%) for anti-MAGE-A3 after five vaccinations. We identified frequent antigen spreading following MAGE-A4 vaccinations without associations with the clinical response or patient prognosis.

CONCLUSION

Antigen spreading pattern might reflect tumor shrinkage as a response to treatment and treatment history (clinical trial registration number: UMIN000001999).

The key role of calreticulin in immunomodulation induced by chemotherapeutic agents

BACKGROUND

It has recently been shown that certain chemotherapeutic agents can improve host immune responses. The present study aimed to demonstrate the mechanism by which chemotherapeutic agents modify the tumor microenvironment and induce tumor-specific immune responses.

METHODS

Three mouse cancer cell lines [CT26 mouse colon cancer cells, B16 melanoma cells and Lewis lung carcinoma (LLC)], 5 human carcinoma cell lines (human esophageal squamous cell carcinoma cell lines TE8 and HEC46 and the human pancreatic carcinoma cell lines PK-9, AsPC-1 and SUIT-2) and 5 chemotherapeutic agents [mitoxantrone (MIT), mitomycin C(MMC), 5-fluorouracil (5FU), camptothecin (CPT-11) and cisplatin (CDDP)] that are frequently used in a clinical setting for cancer treatment were utilized to investigate the surface expression level of calreticulin and HLA class I after exposure to chemotherapeutic agents.

RESULTS

Increased calreticulin (CRT) expression on the surface of mouse cell lines and, moreover, increased surface expression levels of both CRT and HLA class I in all human cell lines were observed in cells treated by the chemotherapeutic agents as compared with non-treated cells. The surface expression level of CRT was significantly correlated with the HLA class I expression level in all human cell lines.

CONCLUSIONS

In conclusion, chemotherapeutic drugs can improve the immunogenicity of cancer cells in a cell-specific manner through the mechanism of translocation of CRT.