Reactive stroma and trastuzumab resistance in HER2-positive early breast cancer

[The immunocytokine FAP-IL2v : a potent co-therapy for preventing resistance to trastuzumab in HER2+ breast cancer]

Dans le cadre de leur module d’analyse scientifique, des étudiants des promotions 2022-2023 et 2023-2024 des Master 2 « Immunologie Translationnelle et Biothérapies » (ITB) et « Immunologie Intégrative et Systémique » (I2S) (Mention Biologie Moléculaire et Cellulaire, Parcours Immunologie, Sorbonne Université) se sont penchés sur la littérature et ont pris la plume pour partager avec les lecteurs de m/s quelques-uns des faits marquants de l’actualité en immunologie. Voici une sélection de quelques-unes de ces nouvelles, illustrant la large palette des axes de recherche en cours sur les mécanismes physiopathologiques des maladies infectieuses, auto-immunes, inflammatoires et tumorales et sur le développement d’immunothérapies pour le traitement de ces pathologies.

On y découvre ainsi de nouvelles avancées sur l’analyse transcriptomique du microenvironnement inflammatoire de pathologies autoimmunes, sur des aspects mécanistiques impliqués dans la survie des cellules cancéreuses et la réponse immunitaire anti-tumorale des cellules NK, l’interconnexion entre le système immunitaire et le système nerveux périphérique, le développement de nouvelles immunothérapies permettant de cibler préférentiellement le microenvironnement tumoral et la prise en charge des effets secondaires autoimmuns cardiaques induits par les immunothérapies.

Toute l’équipe pédagogique remercie également chaleureusement les différents tuteurs, experts dans le domaine en lien avec les nouvelles, qui ont accompagné avec bienveillance et enthousiasme le travail de nos étudiants !

Combining the tumor-stroma ratio with tumor-infiltrating lymphocytes improves the prediction of pathological complete response in breast cancer patients

PURPOSE

The tumor-stroma ratio (TSR) is a common histological parameter that measures stromal abundance and is prognostic in breast cancer (BC). However, more evidence is needed on the predictive value of the TSR for the pathological complete response (pCR) to neoadjuvant chemotherapy (NAC). The purpose of this study was to determine the importance of the TSR in predicting pCR in NAC settings.

METHOD

We evaluated the TSR on pretreatment biopsies of 912 BC patients from four independent Chinese hospitals and investigated the potential value of the TSR for predicting pCR. Meanwhile, stromal tumor-infiltrating lymphocytes (sTILs) were assessed, and we evaluated the predictive value of the combination of sTILs and TSR (TSRILs).

RESULTS

Patients with low stroma showed a higher pCR rate than those with high stroma among the four independent hospitals, and in multivariate analysis, the TSR was proven to be an independent predictor for pCR to NAC with an odds ratio of 1.945 (95% CI 1.230-3.075, P = 0.004). Moreover, we found that TSRILs could improve the area under the curve (AUC) for predicting pCR from 0.750 to 0.785 (P = 0.039); especially in HER2-negative BCs, the inclusion of TSRILs increased the AUC from 0.801 to 0.835 in the discovery dataset (P = 0.048) and 0.734 to 0.801 in the validation dataset (P = 0.003).

CONCLUSION

TSR and sTILs can be easily measured in pathological routines and provide predictive information without additional cost; with more evidence from clinical trials, TSRILs could be a candidate to better stratify patients in NAC settings.

Whole slide image features predict pathologic complete response and poor clinical outcomes in triple-negative breast cancer

INTRODUCTION

Breast cancers are complex ecosystem like networks of malignant cells and their associated microenvironment. Applications for machine intelligence and the tumoral microenvironment are expanding frontiers in pathology. Previously, computational approaches have been developed to quantify and spatially analyze immune cells, proportionate stroma, and detect tumor budding. Little work has been done to analyze different types of tumor-associated stromata both quantitatively and computationally in relation to clinical endpoints.

METHODS

We aimed to quantify stromal features from whole slide images (WSI) including stromata (myxoid, collagenous, immune) and tumoral components and combined them with traditional clinical and pathologic parameters in 120 triple-negative breast cancer (TNBC) patients treated with neoadjuvant chemotherapy (NAC) to predict pathologic complete response (pCR) and poor clinical outcomes.

RESULTS

High collagenous stroma on WSI was best associated with lower rates of pCR, while combined high proportionated stroma (myxoid, collagenous, and immune) most optimally predicted worse clinical survival outcomes. When combining clinical, pathologic, and WSI features, Receiver Operator Characteristics (ROC) curves for LASSO features was up to 0.67 for pCR and 0.77 for poor outcomes.

CONCLUSION

The techniques demonstrated in the present study can be performed with appropriate quality assurance. Future trials are needed to demonstrate whether coupling applications for machine intelligence, inclusive of the tumor mesenchyme, can improve outcomes prediction for patients with breast cancer.

Next Generation Sequencing of Reactive Stroma and Residual Breast Cancer Cells in Tumor Bed after Neoadjuvant Chemotherapy

Primary systemic or neoadjuvant chemotherapy of breast cancer has become a standard therapy option in locally advanced or predefined intrinsic subtypes such as triple negative or Her2 positive breast cancer. Neoadjuvant chemotherapy can result in complete pathological response without residual tumor cells (tumor bed) or partial response and non-response with different amounts of reactive stroma and residual tumor cells. The interaction between therapy regimens and tumoral driver mutations have been extensively studied, although the reactive stroma of the tumor bed received less attention. In this study, we characterized the mutational status of residual breast cancer cells and reactive tumor stroma devoid of residual tumor cells in partial or non-responders using next generation sequencing. Twenty-one post-therapeutic breast surgical specimens after neoadjuvant chemotherapy underwent pathogenic driver-mutation screening using microdissected residual breast cancer cells and in reactive stroma adjacent to tumor bed areas. In reactive stroma, no mutations could be validated. In residual breast cancer cells, mutations were detected in sixteen of twenty-one cases (76%). In nine of these twenty-one cases (43%), pathogenic driver mutations (PIK3CA, PTEN, TP53, FN1, PLAG1) were identified. Pathogenic driver-mutations are exclusively restricted to residual carcinoma cells and are absent in reactive stroma independently from intrinsic breast cancer subtypes or tumor stage. These data suggest that the absence of pathogenic mutations in a tumor bed without residual tumor cells may have prognostic implications after neoadjuvant chemotherapy.

Cancer-associated fibroblasts: Origin, function, imaging, and therapeutic targeting

The tumor microenvironment (TME) is emerging as one of the primary barriers in cancer therapy. Cancer-associated fibroblasts (CAF) are a common inhabitant of the TME in several tumor types and play a critical role in tumor progression and drug resistance via different mechanisms such as desmoplasia, angiogenesis, immune modulation, and cancer metabolism. Due to their abundance and significance in pro-tumorigenic mechanisms, CAF are gaining attention as a diagnostic target as well as to improve the efficacy of cancer therapy by their modulation. In this review, we highlight existing imaging techniques that are used for the visualization of CAF and CAF-induced fibrosis and provide an overview of compounds that are known to modulate CAF activity. Subsequently, we also discuss CAF-targeted and CAF-modulating nanocarriers. Finally, our review addresses ongoing challenges and provides a glimpse into the prospects that can spearhead the transition of CAF-targeted therapies from opportunity to reality.

Targeted immunotherapy against distinct cancer-associated fibroblasts overcomes treatment resistance in refractory HER2+ breast tumors

About 50% of human epidermal growth factor receptor 2 (HER2)+ breast cancer patients do not benefit from HER2-targeted therapy and almost 20% of them relapse after treatment. Here, we conduct a detailed analysis of two independent cohorts of HER2+ breast cancer patients treated with trastuzumab to elucidate the mechanisms of resistance to anti-HER2 monoclonal antibodies. In addition, we develop a fully humanized immunocompetent model of HER2+ breast cancer recapitulating ex vivo the biological processes that associate with patients’ response to treatment. Thanks to these two approaches, we uncover a population of TGF-beta-activated cancer-associated fibroblasts (CAF) specific from tumors resistant to therapy. The presence of this cellular subset related to previously described myofibroblastic (CAF-S1) and podoplanin+ CAF subtypes in breast cancer associates with low IL2 activity. Correspondingly, we find that stroma-targeted stimulation of IL2 pathway in unresponsive tumors restores trastuzumab anti-cancer efficiency. Overall, our study underscores the therapeutic potential of exploiting the tumor microenvironment to identify and overcome mechanisms of resistance to anti-cancer treatment.

A substantial proportion of HER2+ breast cancer patients do not benefit from HER2-targeted therapy. Here, the authors identify a population of cancer-associated fibroblasts involved in the suppression of trastuzumab-induced ADCC that can be pharmacologically targeted to raise treatment effectiveness in unresponsive tumors.

Bête Noire of Chemotherapy and Targeted Therapy: CAF-Mediated Resistance

Simple Summary

Tumor cells struggle to survive following treatment. The struggle ends in either of two ways. The drug combination used for the treatment blocks the proliferation of tumor cells and initiates apoptosis of cells, which is a win for the patient, or tumor cells resist the effect of the drug combination used for the treatment and continue to evade the effect of anti-tumor drugs, which is a bête noire of therapy. Cancer-associated fibroblasts are the most abundant non-transformed element of the microenvironment in solid tumors. Tumor cells play a direct role in establishing the cancer-associated fibroblasts’ population in its microenvironment. Since cancer-associated fibroblasts are activated by tumor cells, cancer-associated fibroblasts show unconditional servitude to tumor cells in their effort to resist treatment. Thus, cancer-associated fibroblasts, as the critical or indispensable component of resistance to the treatment, are one of the most logical targets within tumors that eventually progress despite therapy. We evaluate the participatory role of cancer-associated fibroblasts in the development of drug resistance in solid tumors. In the future, we will establish the specific mode of action of cancer-associated fibroblasts in solid tumors, paving the way for cancer-associated-fibroblast-inclusive personalized therapy.

Abstract

In tumor cells’ struggle for survival following therapy, they resist treatment. Resistance to therapy is the outcome of well-planned, highly efficient adaptive strategies initiated and utilized by these transformed tumor cells. Cancer cells undergo several reprogramming events towards adapting this opportunistic behavior, leading them to gain specific survival advantages. The strategy involves changes within the transformed tumors cells as well as in their neighboring non-transformed extra-tumoral support system, the tumor microenvironment (TME). Cancer-Associated Fibroblasts (CAFs) are one of the components of the TME that is used by tumor cells to achieve resistance to therapy. CAFs are diverse in origin and are the most abundant non-transformed element of the microenvironment in solid tumors. Cells of an established tumor initially play a direct role in the establishment of the CAF population for its own microenvironment. Like their origin, CAFs are also diverse in their functions in catering to the pro-tumor microenvironment. Once instituted, CAFs interact in unison with both tumor cells and all other components of the TME towards the progression of the disease and the worst outcome. One of the many functions of CAFs in influencing the outcome of the disease is their participation in the development of resistance to treatment. CAFs resist therapy in solid tumors. A tumor–CAF relationship is initiated by tumor cells to exploit host stroma in favor of tumor progression. CAFs in concert with tumor cells and other components of the TME are abettors of resistance to treatment. Thus, this liaison between CAFs and tumor cells is a bête noire of therapy. Here, we portray a comprehensive picture of the modes and functions of CAFs in conjunction with their role in orchestrating the development of resistance to different chemotherapies and targeted therapies in solid tumors. We investigate the various functions of CAFs in various solid tumors in light of their dialogue with tumor cells and the two components of the TME, the immune component, and the vascular component. Acknowledgment of the irrefutable role of CAFs in the development of treatment resistance will impact our future strategies and ability to design improved therapies inclusive of CAFs. Finally, we discuss the future implications of this understanding from a therapeutic standpoint and in light of currently ongoing and completed CAF-based NIH clinical trials.

Proteomic analysis of archival breast cancer clinical specimens identifies biological subtypes with distinct survival outcomes

Despite advances in genomic classification of breast cancer, current clinical tests and treatment decisions are commonly based on protein level information. Formalin-fixed paraffin-embedded (FFPE) tissue specimens with extended clinical outcomes are widely available. Here, we perform comprehensive proteomic profiling of 300 FFPE breast cancer surgical specimens, 75 of each PAM50 subtype, from patients diagnosed in 2008-2013 (n = 178) and 1986-1992 (n = 122) with linked clinical outcomes. These two cohorts are analyzed separately, and we quantify 4214 proteins across all 300 samples. Within the aggressive PAM50-classified basal-like cases, proteomic profiling reveals two groups with one having characteristic immune hot expression features and highly favorable survival. Her2-Enriched cases separate into heterogeneous groups differing by extracellular matrix, lipid metabolism, and immune-response features. Within 88 triple-negative breast cancers, four proteomic clusters display features of basal-immune hot, basal-immune cold, mesenchymal, and luminal with disparate survival outcomes. Our proteomic analysis characterizes the heterogeneity of breast cancer in a clinically-applicable manner, identifies potential biomarkers and therapeutic targets, and provides a resource for clinical breast cancer classification.

Protein level information enables the identification of potential biomarkers and therapeutic targets for breast cancer. Here, the authors perform proteomic analysis of 2 cohorts of breast cancer surgical specimens and identify distinct subtypes, immune features and survival outcomes.

The Prognostic Role of Intratumoral Stromal Content in Lobular Breast Cancer

Simple Summary

High intratumoral stromal content is related to worse outcomes in several types of cancer. However, its prognostic role in breast cancer seems to differ between different subtypes. High intratumoral stromal content is a negative prognostic marker in triple-negative breast cancer, while the opposite is the case for estrogen-receptor-positive breast cancer, in which higher stromal content is indicative of a better prognosis. Most lobular breast cancers are estrogen-receptor-positive, and the tumor tissue has a clearly defined histological appearance, often with a high intratumoral stromal content. To date, the prognostic role of intratumoral stromal content in lobular breast cancer remains unclear. In this study, we aimed to investigate the prognostic importance of intratumoral stromal content in estrogen-receptor-positive lobular breast cancer. Our results show that high intratumoral stromal content is an easily assessed and clinically useful indicator of a good prognosis in lobular breast cancer.

Abstract

Previous studies have shown that high intratumoral stromal content is associated with a worse prognosis in breast cancer, especially in the triple-negative subtype. However, contradictory results have been reported for estrogen-receptor-positive (ER+) breast cancer, indicating that the prognostic role of intratumoral stromal content may be subtype-dependent. In this study, we investigated the importance of intratumoral stromal content for breast cancer-specific mortality (BCM) in a well-defined subgroup (n = 182) of ER+/human-epidermal growth-factor-receptor-2 negative (HER2−) invasive lobular breast cancer (ILC). The intratumoral stromal content was assessed on hematoxylin–eosin-stained whole sections and graded into high stroma (>50%) or low stroma (≤50%). A total of 82 (45%) patients had high-stroma tumors, and 100 (55%) had low-stroma tumors. High-stroma tumors were associated with a lower Nottingham histological grade, low Ki67, and a luminal A-like subtype. After a 10-year follow-up, the patients with high-stroma tumors had a lower BCM (HR: 0.43, 95% CI: 0.21–0.89, p = 0.023) in univariable analysis. Essentially the same effect was found in both the multivariable analysis (10-year follow-up) and univariable analysis (25-year follow-up), but these findings were not strictly significant. In ER+/HER2− ILC, high intratumoral stromal content is an easily assessable histological indicator of a good prognosis.

Integrated Analysis of Transcriptome and Differential Methylation of Neurofibromatosis Type 2 Vestibular Schwannomas

BACKGROUND

Vestibular schwannoma is the third most common benign intracranial tumor that can occur sporadically or be associated with neurofibromatosis type 2 (neurofibromatosis type 2 vestibular schwannoma [NF2-VS]). The aim of this study is to provide a comprehensive bioinformatic analysis of methylated-differentially expressed genes (MDEGs) in NF2-VS.

METHODS

Transcriptional sequencing datasets (GSE141801 and GSE108524) and gene methylation microarrays (GSE56598) from the Gene Expression Omnibus database were used to identify and analyze MDEGs in NF2-VS. A protein-protein interaction (PPI) network was built, and the hub genes and modules were identified. Finally, potential pharmacotherapy targeting MDEGs were extracted for NF2-VS.

RESULTS

A total of 57 hypermethylation-low expression genes and 88 hypomethylation-high expression genes were identified. Pathways associated with aberrantly MDEGs included P13K-AKT, MAPK, and Ras, which were also involved in NF2-VS. Six hub genes (EGFR, CCND1, CD53, CSF1R, PLAU, and FGFR1) were identified from the PPI network. Modification of the aforementioned genes altered cell-to-cell communication, response to stimulus, cellular regulation, and membrane and protein bindings. Thirty drugs targeting these pathways were selected based on the hub genes.

CONCLUSIONS

Analysis of MDEGs may enrich the understanding of the molecular mechanisms of NF2-VS pathogenesis and lay the groundwork for potential biomarkers and therapeutic targets for NF2-VS.

Preclinical and Clinical Characterization of Fibroblast-derived Neuregulin-1 on Trastuzumab and Pertuzumab Activity in HER2-positive Breast Cancer

PURPOSE

To characterize expression of neuregulin-1 (NRG1), an HER3 ligand, in HER2-positive breast cancer and its relation with the efficacy of trastuzumab with or without pertuzumab.

EXPERIMENTAL DESIGN

Characterization of NRG1 expression in tumor cell lines, in tumor specimens, and in cancer-associated fibroblasts (CAFs). Patient-derived CAFs were used to investigate NRG1 impact on the activity of trastuzumab with or without pertuzumab in HER2-positive breast cancer cells. The relationship between NRG1 expression and pathologic response to anti-HER2-based neoadjuvant therapy was assessed in a retrospective patient cohort and in the NeoSphere trial.

RESULTS

NRG1 was expressed in HER2-positive breast cancer-derived fibroblasts at significantly higher levels than in cancer cells. NRG1 and the conditioned media (CM) from CAFs phosphorylated HER3 and AKT in cancer cells and mediated trastuzumab resistance. Stable genetic depletion of NRG1 from CAFs overcame trastuzumab resistance. Pertuzumab effectively suppressed trastuzumab resistance mediated by either NRG1 or CAF's CM. NRG1 engaged an epithelial-to-mesenchymal transition that was prevented by trastuzumab and pertuzumab. In clinical samples, stromal and/or tumor cell expression of NRG1 determined by immunohistochemistry was uncommon (13.2%) yet significantly linked with residual disease following trastuzumab-based neoadjuvant therapy. In the NeoSphere trial, the magnitude of the difference of pathologic complete response rates favoring the pertuzumab arm was higher in the NRG1-high group.

CONCLUSIONS

CAF-derived NRG1 mediates trastuzumab resistance through HER3/AKT, which might be reverted by pertuzumab. In patients with HER2-positive breast cancer, high expression of NRG1 was associated to poor response to trastuzumab, but not in combination with pertuzumab.

PLAU directs conversion of fibroblasts to inflammatory cancer-associated fibroblasts, promoting esophageal squamous cell carcinoma progression via uPAR/Akt/NF-κB/IL8 pathway

Cancer-associated fibroblasts (CAFs) plays an important role in the tumor microenvironment. The heterogeneity of CAFs affects the effect of CAFs on promoting or inhibiting tumors, which can be regulated by other cells in the tumor microenvironment through paracrine methods. The urokinase-type plasminogen activator (PLAU) system mediates cell proliferation, migration, adhesion, and other functions through the proteolytic system, intracellular signal transduction, and chemokine activation. PLAU promotes tumor progression in many tumors. We explored the function of PLAU in ESCC and the influence of PLAU secreted by tumor cells on the heterogeneity of CAFs. We found that PLAU is highly expressed in ESCC, which is related to poor prognosis and can be used as a prognostic marker for ESCC. Through loss-of function and gain-of function experiments, we found that PLAU promoted ESCC proliferation and clone formation via MAPK pathway, and promotes migration by upregulating Slug and MMP9, which can be reversed by the MEK 1/2 inhibitor U0126. At the same time, through sequencing, cytokine detection, and RT-qPCR verification, we found that tumor cells secreted PLAU promoted the conversion of fibroblasts to inflammatory CAFs, which upregulated expression and secretion of IL8 via the uPAR/Akt/NF-κB pathway. The IL8 secreted by CAFs in turn promotes the high expression of PLAU in tumor cells and further promoted the progression of ESCC. In summary, PLAU was not only a prognostic marker of ESCC, which promoted tumor cell proliferation and migration, but also promoted the formation of inflammatory CAFs by the PLAU secreted by tumor cells.

A pan-cancer analysis of HER2 index revealed transcriptional pattern for precise selection of HER2-targeted therapy

Background

The prevalence of HER2 alterations in pan-cancer indicates a broader range of application of HER2-targeted therapies; however, biomarkers for such therapies are still insufficient and limited to breast cancer and gastric cancer.

Methods

Using multi-omics data from The Cancer Genome Atlas (TCGA), the landscape of HER2 alterations was exhibited across 33 tumor types. A HER2 index was constructed using one-class logistic regression (OCLR). With the predictive value validated in GEO cohorts and pan-cancer cell lines, the index was then applied to evaluate the HER2-enriched expression pattern across TCGA pan-cancer types.

Findings

Increased HER2 somatic copy number alterations (SCNAs) could be divided into two patterns, focal- or arm-level. The expression-based HER2 index successfully distinguished the HER2-enriched subtype from the others and provided a stable and superior performance in predicting the response to HER2-targeted therapies both in breast tumor tissue and pan-cancer cell lines. With frequencies varying from 12.0% to 0.9%, tumors including head and neck squamous tumors, gastrointestinal tumors, bladder cancer, lung cancer and uterine tumors exhibited high HER2 indices together with HER2 amplification or overexpression, which may be more suitable for HER2-targeted therapies. The BLCA.3 and HNSC.Basal were the most distinguishable subtypes within bladder cancer and head and neck cancer respectively by HER2 index, implying their potential benefits from HER2-targeted therapies.

Interpretation

As a pan-cancer predictive biomarker of HER2-targeted therapies, the HER2 index could help identify potential candidates for such treatment in multiple tumor types by combining with HER2 multi-omics features. The discoveries of our study highlight the importance of incorporating transcriptional pattern into the assessment of HER2 status for better patient selection.

Funding

The National Key Research and Development Program of China; Clinical Research and Cultivation Project of Shanghai ShenKang Hospital Development Center.