Immunoregulatory effects of human cord blood T lymphocytes on mixed lymphocyte reaction

Fetuses of outbred mammalian species can survive despite disparities of participants' histocompatibility antigens. During pregnancy, maternal immune response is supposed to be suppressed by various immune suppressive mechanisms. In order to know whether fetal lymphocytes can suppress the maternal immune reaction, we investigated the suppressive effect of human newborns' T lymphocytes. Newborn T cells were isolated from the umbilical cord blood by means of the sheep red blood cell rosette forming method and treated with mitomycin C. The newborn T cells were added as regulator cells to one way mixed lymphocyte reaction (MLR) using maternal lymphocytes, paternal lymphocytes and unrelated donor's lymphocytes. In a control study, adult T cells were treated in the same manner. In any combination of the MLR, the response was substantially suppressed by the addition of cord T cells in comparison with the response by the addition of normal adult T cells. The suppression was dose-related with an increasing number of regulator cord T cells. The suppressive activity of cord T cells showed radiation resistance until 1,000 rads irradiation. In the kinetics study, cord T cells were found to suppress the recognition phase of MLR. These results suggest that cord T lymphocytes suppress the mother's immunological reaction to the fetal antigens.     

Real-world effectiveness of third- or later-line treatment in Japanese patients with HER2-positive,unresectable, recurrent or metastatic gastric cancer: a retrospective observational study

Background

Real-world evidence on the preference for and effectiveness of third- or later-line (3L +) monotherapy for HER2-positive gastric cancer is limited in Japan. This study evaluated the utility of nivolumab, irinotecan, and trifluridine/tipiracil (FTD/TPI) monotherapy as 3L + treatment in Japanese patients with HER2-positive gastric/gastroesophageal junction (G/GEJ) cancer who were previously treated with trastuzumab.

Methods

In this multicenter, retrospective, observational study (20 centers), data of eligible patients were extracted from medical records (September 22, 2017–March 31, 2020), with follow-up until June 30, 2020. Outcomes included overall survival (OS), real-world progression-free survival (rwPFS), time to treatment failure (TTF), objective response rate (ORR; complete response [CR] + partial response [PR]), and disease control rate (DCR).

Results

Of 127 enrolled patients, the overall analysis population comprised 117 patients (median [range] age, 71 [38–89] years). The most commonly prescribed 3L + monotherapy was nivolumab (n = 100), followed by irinotecan (n = 12) and FTD/TPI (n = 5). The median (95% confidence interval [CI]) OS, rwPFS, and TTF were 6.2 (4.5–8.0), 1.9 (1.5–2.3), and 1.8 (1.5–2.2) months, respectively, at median (range) 150 (25–1007) days of follow-up. The ORR (CR + PR) and DCR were 9.0% (1% + 8%) and 32.0%, respectively. Factors such as higher neutrophil–lymphocyte ratio (≥ 2.54), Glasgow prognostic score (≥ 1), Eastern Cooperative Oncology Group performance status (ECOG PS; ≥ 2), and hepatic metastasis significantly impacted OS.

Conclusions

The observed OS in this study for HER2-positive G/GEJ cancer was shorter than that reported previously, suggesting that the effectiveness of nivolumab, irinotecan, or FTD/TPI as 3L + therapy may be limited.

     

Immunosuppressive Factors in Ascites Fluids From Ovarian Cancer Patients

ABSTRACT: The nonspecific immunosuppressive effect of ascites fluids from ovarian cancer patients was examined and compared with that of noncancerous abdominal effusion and sera from ovarian cancer patients. The malignant ascites fluids produced a noncytotoxic, dose-dependent suppression of DNA synthesis of phy-tohemagglutinin-stimulated human peripheral blood lymphocytes. The suppression was higher than that observed in sera from cancer patients. No suppressive effect was seen in control abdominal effusion. The factors responsible for inhibition of in vitro lymphocyte function were partially purified from ascites fluid by lentil lectin affinity chromatography and gel filtration. Major active factors had a high molecular weight (440–1500 kilodaltons), an affinity to lentil lectin, and were stable against heat and acid treatment.     

Roles of BIM induction and survivin downregulation in lapatinib-induced apoptosis in breast cancer cells with HER2 amplification

Lapatinib, a dual tyrosine kinase inhibitor of the epidermal growth factor receptor and human epidermal growth factor receptor 2 (HER2), is clinically active in patients with breast cancer positive for HER2 amplification. The mechanism of this anti-tumor action has remained unclear, however. We have now investigated the effects of lapatinib in HER2 amplification-positive breast cancer cells with or without an activating PIK3CA mutation. Lapatinib induced apoptosis in association with upregulation of the pro-apoptotic protein Bcl-2 interacting mediator of cell death (BIM) through inhibition of the MEK-ERK signaling pathway in breast cancer cells with HER2 amplification. RNA interference (RNAi)-mediated depletion of BIM inhibited lapatinib-induced apoptosis, implicating BIM induction in this process. The pro-apoptotic effect of lapatinib was less pronounced in cells with a PIK3CA mutation than in those without one. Lapatinib failed to inhibit AKT phosphorylation in PIK3CA mutant cells, likely because of hyperactivation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway by the mutation. Depletion of PIK3CA (a catalytic subunit of PI3K) revealed that survivin expression is regulated by the PI3K pathway in these cells, suggesting that insufficient inhibition of PI3K-survivin signaling is responsible for the limited pro-apoptotic effect of lapatinib in HER2 amplification-positive cells with a PIK3CA mutation. Consistent with this notion, depletion of survivin by RNAi or treatment with a PI3K inhibitor markedly increased the level of apoptosis in PIK3CA mutant cells treated with lapatinib. Our results thus suggest that inhibition of both PI3K-survivin and MEK-ERK-BIM pathways is required for effective induction of apoptosis in breast cancer cells with HER2 amplification.     

High-dose dexamethasone plus antihistamine prevents colorectal cancer patients treated with modified FOLFOX6 from hypersensitivity reactions induced by oxaliplatin

Background

Oxaliplatin is a third-generation platinum compound and a key agent for the management of colorectal cancer. Patients treated with oxaliplatin are at risk for hypersensitivity reactions. We designed a modified premedication regimen to prevent oxaliplatin-related hypersensitivity reactions and assessed if this approach is effective.

Methods

A retrospective cohort study of patients with advanced colorectal cancer who received modified FOLFOX6 (mFOLFOX6) was performed. Patients received routine premedication with dexamethasone 8?mg and granisetron 3?mg for the first five cycles of mFOLFOX6. From the sixth cycle onward, cohort 1 received the same premedication, and cohort 2 received modified premedication (diphenhydramine 50?mg orally, followed by dexamethasone 20?mg, granisetron 3?mg, and famotidine 20?mg). We compared the incidence of hypersensitivity reactions, duration of treatment, and reasons for treatment withdrawal between the two cohorts.

Results

A total of 181 patients were studied (cohort 1, 81; cohort 2, 100). Hypersensitivity reactions developed in 16 patients (20%) in cohort 1 and 7 (7.0%) in cohort 2 (P?=?0.0153). The median number of cycles increased from 9 in cohort 1 to 12 in cohort 2. Apart from progressive disease, neurotoxicity was the reason for discontinuing treatment in 20% of the patients in cohort 1, as compared with 53% in cohort 2.

Conclusion

Increased doses of dexamethasone and antihistamine significantly reduced oxaliplatin-related hypersensitivity reactions. This effective approach should be considered for all patients who receive FOLFOX, allowing treatment to be completed as planned.     

Clinical Application of the FoundationOne CDx Assay to Therapeutic Decision-Making for Patients with Advanced Solid Tumors

BackgroundImplementation of personalized medicine requires the accessibility of tumor molecular profiling in order to allow prioritization of appropriate targeted therapies for individual patients. Our aim was to study the role of comprehensive genomic profiling assays that may inform treatment recommendations for patients with solid tumors.Materials and MethodsWe performed a prospective study to evaluate the feasibility of application of the FoundationOne CDx panel—which detects substitutions, insertions and deletions, and copy number alterations in 324 genes, select gene rearrangements, and genomic signatures including microsatellite instability and tumor mutation burden (TMB)—to patients with advanced or recurrent solid tumors before its approval in Japan.ResultsA total of 181 samples were processed for genomic testing between September 2018 and June 2019, with data being successfully obtained for 175 of these samples, yielding a success rate of 96.7%. The median turnaround time was 41 days (range, 21–126 days). The most common known or likely pathogenic variants were TP53 mutations (n = 113), PIK3CA mutations (n = 33), APC mutations (n = 32), and KRAS mutations (n = 29). Among the 153 patients assessed for TMB, the median TMB was 4 mutations/Mb, and tumors with a high TMB (≥10 mutations/Mb) were more prevalent for lung cancer (11/32) than for other solid tumor types (9/121, Fisher''s exact test p < .01). No clear trend toward increased efficacy for immune checkpoint inhibitor (ICI) monotherapy or ICI combination chemotherapy in patients with a high programmed cell death–ligand 1 tumor proportion score or a high TMB was apparent. Among the 174 patients found to harbor known or likely pathogenic actionable alterations, 24 individuals (14%) received matched targeted therapy.ConclusionThe FoundationOne CDx assay was performed with formalin‐fixed, paraffin‐embedded tumor specimens with a success rate of >95%. Such testing may inform the matching of patients with cancer with investigational or approved targeted drugs.Implications for PracticeThis prospective cohort study was initiated to investigate the feasibility and utility of clinical application of FoundationOne CDx. A total of 181 samples were processed for genomic testing between September 2018 and June 2019, with data being successfully obtained for 175 of these samples, yielding a success rate of 96.7%, and 24 individuals (14%) received matched targeted therapy.