AXL receptor tyrosine kinase has been described as a relevant molecular marker and a key player in invasiveness, especially in triple-negative breast cancer (TNBC).
We evaluate the antitumor efficacy ...of the anti-AXL monoclonal antibody 20G7-D9 in several TNBC cell xenografts or patient-derived xenograft (PDX) models and decipher the underlying mechanisms. In a dataset of 254 basal-like breast cancer samples, genes correlated with
expression are enriched in EMT, migration, and invasion signaling pathways.
Treatment with 20G7-D9 inhibited tumor growth and bone metastasis formation in AXL-positive TNBC cell xenografts or PDX, but not in AXL-negative PDX, highlighting AXL role in cancer growth and invasion.
stimulation of AXL-positive cancer cells by its ligand GAS6 induced the expression of several EMT-associated genes (
, and
) through an intracellular signaling implicating the transcription factor FRA-1, important in cell invasion and plasticity, and increased their migration/invasion capacity. 20G7-D9 induced AXL degradation and inhibited all AXL/GAS6-dependent cell signaling implicated in EMT and in cell migration/invasion.
The anti-AXL antibody 20G7-D9 represents a promising therapeutic strategy in TNBC with mesenchymal features by inhibiting AXL-dependent EMT, tumor growth, and metastasis formation.
.
Background
The correlation between immune cells and the Lauren classification subtypes and their prognostic impact in advanced gastric cancer (AGC) are unknown.
Methods
Circulating natural killer ...(NK) cells, CD4
+
and CD8
+
T cells, regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) were quantified in peripheral blood mononuclear cells (PBMCs) from 67 patients with untreated AGC enrolled in the PRODIGE 17-ACCORD 20 trial. CD56
+
cells (NK), CD8
+
, and FoxP3
+
(Treg) tumor-infiltrating lymphocytes (TILs) were assessed in tumor samples.
Results
Circulating NK and Treg proportions were significantly lower in patients with diffuse/mixed-type AGC (
n
= 27) than those with intestinal type (
n
= 40; median 6.3% vs 11.5%;
p
= 0.02 and median 3.3% vs 5.2%;
p
= 0.03, respectively). Proportions of circulating MDSC, CD4
+
and CD8
+
T cells were not associated with one pathological type. Among tumor-infiltrating cells, CD8
+
T cells, but not NK or FoxP3
+
cells, were significantly lower in diffuse/mixed-type AGC (median 21 vs 59 cells/field;
p
= 0.009). Patients with high circulating NK cell counts (> 17%) had a better overall survival than those with < 17% (HR 0.40; 95% CI 0.15–1.06;
p
= 0.04). Patients with high CD8
+
TIL counts (> 31 cells/field) had significantly longer overall survival (HR 0.44; 95% CI 0.21–0.92;
p
= 0.02). The prognostic value of CD8
+
TILs was maintained after adjustment for confounding factors, including the Lauren classification (HR = 0.42; 95% CI 0.18–0.96;
p
= 0.039).
Conclusion
Diffuse/mixed-type AGC has lower rates of CD8
+
TILs and circulating NK cells and Tregs than the intestinal type. This “cold tumor” phenotype may be associated with a worse outcome.
Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer characterized by poor response to chemotherapy and radiotherapy due to the lack of efficient therapeutic tools and early diagnostic ...markers. We previously generated the nonligand competing anti‐HER3 antibody 9F7–F11 that binds to pancreatic tumor cells and induces tumor regression in vivo in experimental models. Here, we asked whether coupling 9F7–F11 with a radiosensitizer, such as monomethylauristatin E (MMAE), by using the antibody‐drug conjugate (ADC) technology could improve radiation therapy efficacy in PDAC. We found that the MMAE‐based HER3 antibody‐drug conjugate (HER3‐ADC) was efficiently internalized in tumor cells, increased the fraction of cells arrested in G2/M, which is the most radiosensitive phase of the cell cycle, and promoted programmed cell death of irradiated HER3‐positive pancreatic cancer cells (BxPC3 and HPAC cell lines). HER3‐ADC decreased the clonogenic survival of irradiated cells by increasing DNA double‐strand break formation (based on γH2AX level), and by modulating DNA damage repair. Tumor radiosensitization with HER3‐ADC favored the inhibition of the AKT‐induced survival pathway, together with more efficient caspase 3/PARP‐mediated apoptosis. Incubation with HER3‐ADC before irradiation synergistically reduced the phosphorylation of STAT3, which is involved in chemoradiation resistance. In vivo, the combination of HER3‐ADC with radiation therapy increased the overall survival of mice harboring BxPC3, HPAC cell xenografts or patient‐derived xenografts, and reduced proliferation (KI67‐positive cells). Combining auristatin radiosensitizer delivery via an HER3‐ADC with radiotherapy is a new promising therapeutic strategy in PDAC.
What's new?
In pancreatic ductal adenocarcinoma (PDAC), chemoradiation is prescribed to patients with borderline resectable lesions to make surgery possible. The HER3 receptor is a key signaling hub in PDAC. Here, the authors developed a novel antibody‐drug conjugate targeting HER3 (HER3‐ADC) that enhanced radiosensitivity of PDAC by arresting cells in G2/M. HER3‐ADC increased radiation response in mice xenografted with PDAC cells, through inhibition of cell survival and induction of DNA break formation and apoptosis. Combining auristatin radiosensitizer delivery via an HER3‐ADC with radiotherapy could help increase the rate of resection for patients with borderline resectable pancreatic cancer.
STING (Stimulator of Interferon Genes) is an endoplasmic reticulum-anchored adaptor of the innate immunity best known to trigger pro-inflammatory cytokine expression in response to pathogen ...infection. In cancer, this canonical pathway can be activated by intrinsic or drug-induced genomic instability, potentiating antitumor immune responses. Here we report that STING downregulation decreases cell survival and increases sensitivity to genotoxic treatment in a panel of breast cancer cell lines in a cell-autonomous manner. STING silencing impaired DNA Damage Response (53BP1) foci formation and increased DNA break accumulation. These newly identified properties were found to be independent of STING partner cGAS and of its canonical pro-inflammatory pathway. STING was shown to partially localize at the inner nuclear membrane in a variety of breast cancer cell models and clinical tumor samples. Interactomics analysis of nuclear STING identified several proteins of the DNA Damage Response, including the three proteins of the DNA-PK complex, further supporting a role of STING in the regulation of genomic stability. In breast and ovarian cancer patients that received adjuvant chemotherapy, high STING expression is associated with increased risk of relapse. In summary, this study highlights an alternative, non-canonical tumor-promoting role of STING that opposes its well-documented function in tumor immunosurveillance.
Morphological evaluation of tumor-infiltrating lymphocytes (TILs) in breast cancer is gaining momentum as evidence strengthens the clinical relevance of this immunological biomarker. TILs in the ...post-neoadjuvant residual disease setting are acquiring increasing importance as a stratifying marker in clinical trials, considering the raising interest on immunotherapeutic strategies after neoadjuvant chemotherapy. TILs in ductal carcinoma in situ, with or without invasive carcinoma, represent an emerging area of clinical breast cancer research. The aim of this report is to update pathologists, clinicians and researchers on TIL assessment in both the post-neoadjuvant residual disease and the ductal carcinoma in situ settings. The International Immuno-Oncology Working Group proposes a method for assessing TILs in these settings, based on the previously published International Guidelines on TIL Assessment in Breast Cancer. In this regard, these recommendations represent a consensus guidance for pathologists, aimed to achieve the highest possible consistency among future studies.
In the era of immune checkpoint inhibitors, understanding the metastatic microenvironment of proficient mismatch repair/microsatellite stable (pMMR/MSS) colorectal cancer (CRC) is of paramount ...importance to both prognostication and the development of more effective novel therapies. In this study, primary and paired metastasis tissue samples were collected from patients with resectable metastatic CRC treated with adjuvant FOLFOX or peri‐operative chemotherapy in the MIROX phase III prospective study. In total, 74 cancer tissues were stained for CD3, CD8, Forkhead box protein 3 (FOXP3), programmed cell death protein‐1 (PD‐1, invasive front, stromal, intra‐epithelial compartments), and programmed death‐ligand 1 (PD‐L1, tumor, immune cells). The immune profiling of primary CRC had a limited value to predict the immune context of paired metastases for all markers but CD3+. The expression of CD8 and PD‐L1 was higher in metastases after neoadjuvant FOLFOX. In metastases, both CD3 T cells at the invasive front and PD‐L1 expressions on immune cells were predictive of better disease‐free survival. These results show that the effect of FOLFOX on modifying the immune microenvironment in resected CRC metastases and measurement of PD‐L1 expression and tumor‐infiltrating CD8 T cells in pMMR/MSS metastatic tissue samples could improve treatment strategies of metastatic CRC patients.
Here, we characterized the immune microenvironment of proficient mismatch repair/microsatellite stable oligometastatic patients with colorectal cancer (CRC) treated with the neoadjuvant FOLFOX. Primary tumor immune profiling had limited predictive value in estimating the metastatic immune context. CD3 T cells and PD‐L1 immune cells at the invasive front were predictive of disease‐free survival. In addition, the expression of CD8 and PD‐L1 was higher after FOLFOX treatment. Thus, CD8high/PD‐L1high signature could be related to chemotherapy response and could improve treatment strategies of metastatic patients with CRC.
The microbiota includes different microorganisms consisting of bacteria, fungi, viruses, and protozoa distributed over many human body surfaces including the skin, vagina, gut, and airways, with the ...highest density found in the intestine. The gut microbiota strongly influences our metabolic, endocrine, and immune systems, as well as both the peripheral and central nervous systems. Recently, a dialogue between the gut and lung microbiota has been discovered, suggesting that changes in one compartment could impact the other compartment, whether in relation to microbial composition or function. Further, this bidirectional axis is evidenced in an, either beneficial or malignant, altered immune response in one compartment following changes in the other compartment. Stimulation of the immune system arises from the microbial cells themselves, but also from their metabolites. It can be either direct or mediated by stimulated immune cells in one site impacting the other site. Additionally, this interaction may lead to immunological boost, assisting the innate immune system in its antitumour response. Thus, this review offers an insight into the composition of these sites, the gut and the lung, their role in shaping the immune system, and, finally, their role in the response to lung cancer.
Objectives/Hypothesis
Recent preclinical and clinical studies on head and neck squamous cell carcinoma (HNSCC) revealed synergistic effects when combining anti‐EGFR agents with conventional ...chemotherapeutic drugs. Activation of the PI3‐kinase/AKT/mTOR signaling pathway has been identified as an important mechanism implicated in tumor progression and resistance to EGFR inhibitors. The aim of this study was to investigate the effects of combining the mTOR inhibitor temsirolimus (Tem) with the anti‐EGFR agent cetuximab (Cet) and conventional chemotherapeutic drugs (cisplatin and fluorouracil (C/F)) on an orthotopic model of HNSCC.
Study Design
Preclinical in vivo study.
Methods
We evaluated the anti‐tumor efficacy (measured tumor volume) of Tem, Cet, and C/F, administered alone or in combination. Investigations were performed using a human HNSCC cell line, CAL33, injected into the mouth floor of nude mice.
Results
As compared with the control, the combination of Tem and Cet led to the highest tumor inhibition and induced almost complete tumor growth arrest (P = 0.001). Tem significantly enhanced the impact of the Cet‐C/F combination on tumor growth (P < 0.001). The highest inhibitory effects of treatments on cell proliferation (Ki67 labeling), MAPK (pP42/44 labeling), and PI3K/AKT/mTOR (pS6R labeling) signaling pathways were found with the Tem‐Cet association.
Conclusion
In this orthotopic HNSCC model, the combination of Tem with Cet produced synergistic effects on tumor growth. These results were corroborated by a strong inhibition of both MAPK and PI3K‐mTOR signaling pathways.
Level of Evidence
N/A. Laryngoscope, 126:E156–E163, 2016
Patient stratification has been instrumental for the success of targeted therapies in breast cancer. However, the molecular basis of metastatic breast cancer and its therapeutic vulnerabilities ...remain poorly understood. Here we show that PML is a novel target in aggressive breast cancer. The acquisition of aggressiveness and metastatic features in breast tumours is accompanied by the elevated PML expression and enhanced sensitivity to its inhibition. Interestingly, we find that STAT3 is responsible, at least in part, for the transcriptional upregulation of PML in breast cancer. Moreover, PML targeting hampers breast cancer initiation and metastatic seeding. Mechanistically, this biological activity relies on the regulation of the stem cell gene SOX9 through interaction of PML with its promoter region. Altogether, we identify a novel pathway sustaining breast cancer aggressiveness that can be therapeutically exploited in combination with PML-based stratification.
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