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Abstract Selective KRASG12C inhibitors have been developed to covalently lock the oncogene in the inactive GDP-bound state. Two of these molecules, sotorasib and adagrasib, are approved for the treatment of adult patients with KRASG12C-mutated previously treated advanced non-small cell lung cancer. Drug treatment imposes selective pressures leading to the outgrowth of drug-resistant variants. Mass sequencing from patients’ biopsies identified a number of acquired KRAS mutations -both in cis and in trans- in resistant tumors. We demonstrate here that disease progression in vivo can also occur due to adaptive mechanisms and increased KRAS-GTP loading. Using the preclinical tool tri-complex KRASG12C-selective covalent inhibitor, RMC-4998 (also known as RM-029), that targets the active GTP-bound (ON) state of the oncogene, we provide a proof-of-concept that the clinical stage KRASG12C(ON) inhibitor RMC-6291 alone or in combination with KRASG12C(OFF) drugs can be an alternative potential therapeutic strategy to circumvent resistance due to increased KRAS-GTP loading.

High‐grade serous ovarian cancer (HGSOC) is the deadliest gynecological malignancy. The most common form of metastatic spread of HGSOC is transcoelomic dissemination. In this process, detached cells from the primary tumor aggregate as tumorspheres and promote the accumulation of peritoneal ascites. This represents an early event in HGSOC development and is indicative of poor prognosis. In this study, based on tumorspheres isolated from ascitic liquid samples from HGSOC patients, ovarian cancer spheroid 3D cultures, and in vivo models, we describe a key signal for tumorsphere formation in HGSOC. We report that platelet‐derived growth factor receptor beta (PDGFRβ) is essential for fibronectin‐mediated cell clustering of ovarian cancer cells into tumorspheres. This effect is mediated by the kinase NUAK family SNF1‐like kinase 1 (NUAK1) and blocked by PDGFRβ pharmacological or genetic inhibition. In the absence of PDGFRβ, ovarian cancer cells can be provided with fibronectin by cancer‐associated fibroblasts to generate chimeric spheroids. This work provides new insights that uncover potential targets to prevent peritoneal dissemination, the main cause of advanced disease in HGSOC patients.

Cyclin‐dependent kinases (CDKs), together with their cyclin partners, are the master cell cycle regulators. Remarkably, the cyclin family was extended to include atypical cyclins, characterized by distinctive structural features, but their partner CDKs remain elusive. Here, we conducted a yeast two‐hybrid screen to identify new atypical cyclin–CDK complexes. We identified 10 new complexes, including a complex between CDK6 and cyclin I (CCNI), which was found to be active against retinoblastoma protein. CCNI upregulation increased the proliferation of breast cancer cells in vitro and in vivo, with a magnitude similar to that seen upon cyclin D upregulation, an effect that was abrogated by CDK6 silencing or palbociclib treatment. In line with these findings, CCNI downregulation led to a decrease in cell number and a reduction in the percentage of cells reaching S phase. Finally, CCNI upregulation correlated with the high expression of E2F target genes in large panels of cancer cell lines and tissue samples from breast cancer patients. In conclusion, we unveil CCNI as a new player in the pathways that activate CDK6, enriching the wiring of cell cycle control.

Uterine serous carcinoma (USC) is an aggressive form of endometrial cancer (EC), characterized by its high propensity for metastases. In fact, while endometrioid endometrial carcinoma (EEC), which accounts for 85% of EC, presents a good prognosis, USC is the most frequently fatal. Herein, we used for the first time a peptide‐based tyrosine‐kinase‐activity profiling approach to quantify the changes in tyrosine kinase activation between USC and EEC. Among the tyrosine kinases highly activated in USC, we identified focal adhesion kinase (FAK). We conducted mechanistic studies using cellular models. In a USC cell line, targeting FAK either by inhibitors PF‐573228 and defactinib (VS‐6063) or by gene silencing limits 3D cell growth and reduces cell migration. Moreover, results from our studies suggest that oxidative stress is increased in USC tumors compared to EEC ones. Reactive oxygen species (ROS) induce tyrosine phosphorylation of FAK and a concomitant tyrosine phosphorylation of paxillin, a mediator of FAK signal transduction. Mechanistically, by tracking hundreds of individual cells per condition, we show that ROS increased cell distance and migration velocity, highlighting the role of ROS‐FAK‐PAX signaling in cell migration. Both defactinib and ROS scavenger N‐acetylcysteine (NAC) revert this effect, pointing toward ROS as potential culprits for the increase in USC cell motility. A proof of concept of the role of FAK in controlling cell growth was obtained in in vivo experiments using cancer‐tissue‐originated spheroids (CTOS) and a patient‐derived orthotopic xenograft model (orthoxenograft/PDOX). Defactinib reduces cell proliferation and protein oxidation, supporting a pro‐tumoral antioxidant role of FAK, whereas antioxidant NAC reverts FAK inhibitor effects. Overall, our data points to ROS‐mediated FAK activation in USC as being responsible for the poor prognosis of this tumor type and emphasize the potential of FAK inhibition for USC treatment.

Summary: Background: The incidence of endometrial cancer is increasing worldwide. While delays in diagnosis reduce survival, case molecular misclassification might be associated with under- and over-treatment. The objective of this study was to evaluate genetic alterations to detect and molecularly classify cases of endometrial cancer using non-invasive samples. Methods: Consecutive patients with incident endometrial cancer (N = 139) and controls (N = 107) from a recent Spanish case–control study were included in this analysis. Overall, 339 cervicovaginal samples (out of which 228 were clinician-collected and 111 were self-collected) were analysed using a test based on next-generation sequencing (NGS), which targets 47 genes. Immunohistochemical markers were evaluated in 133 tumour samples. A total of 159 samples were used to train the detection algorithm and 180 samples were used for validation. Findings: Overall, 73% (N = 94 out of 129 clinician-collected samples, and N = 66 out of 90 self-collected samples) of endometrial cancer cases had detectable mutations in clinician-collected and self-collected samples, while the specificity was 80% (79/99) for clinician-collected samples and 90% (19/21) for self-collected samples. The molecular classifications obtained using tumour samples and non-invasive gynaecologic samples in our study showed moderate-to-good agreement. The molecular classification of cases of endometrial cancer into four groups using NGS of both clinician-collected and self-collected cervicovaginal samples yielded significant differences in disease-free survival. The cases with mutations in POLE had an excellent prognosis, whereas the cases with TP53 mutations had the poorest clinical outcome, which is consistent with the data on tumour samples. Interpretation: This study classified endometrial cancer cases into four molecular groups based on the analysis of cervicovaginal samples that showed significant differences in disease-free survival. The molecular classification of endometrial cancer in non-invasive samples may improve patient care and survival by indicating the early need for aggressive surgery, as well as reducing referrals to highly specialized hospitals in cancers with good prognosis. Validation in independent sets will confirm the potential for molecular classification in non-invasive samples. Funding: This study was funded by a competitive grant from Instituto de Salud Carlos III through the projects PI19/01835, PI23/00790, and FI20/00031, CIBERESP CB06/02/0073 and CIBERONC CB16/12/00231, CB16/12/00234 (Co-funded by European Regional Development Fund. ERDF: A way to build Europe). Samples and data were provided by Biobank HUB-ICO-IDIBELL, integrated into the Spanish Biobank Network, and funded by the Instituto de Salud Carlos III (PT20/00171) and by Xarxa de Bancs de Tumors de Catalunya (XBTC) sponsored by Pla Director d’Oncologia de Catalunya. This work was supported in part by the AECC, Grupos estables (GCTRA18014MATI). It also counts with the support of the Secretariat for Universities and Research of the Department of Business and Knowledge of the Generalitat de Catalunya, and grants to support the activities of research groups 2021SGR01354 and 2021SGR1112.

Abstract Clinical management of endometrial cancer (EC) is handicapped by the limited availability of second line treatments and bona fide molecular biomarkers to predict recurrence. These limitations have hampered the treatment of these patients, whose survival rates have not improved over the last four decades. The advent of coordinated studies such as The Cancer Genome Atlas Uterine Corpus Endometrial Carcinoma (TCGA_UCEC) has partially solved this issue, but the lack of proper experimental systems still represents a bottleneck that precludes translational studies from successful clinical testing in EC patients. Within this context, the first study reporting the generation of a collection of endometrioid‐EC‐patient‐derived orthoxenograft (PDOX) mouse models is presented that is believed to overcome these experimental constraints and pave the way toward state‐of‐the‐art precision medicine in EC. The collection of primary tumors and derived PDOXs is characterized through an integrative approach based on transcriptomics, mutational profiles, and morphological analysis; and it is demonstrated that EC tumors engrafted in the mouse uterus retain the main molecular and morphological features from analogous tumor donors. Finally, the molecular properties of these tumors are harnessed to assess the therapeutic potential of trastuzumab, a human epidermal growth factor receptor 2 (HER2) inhibitor with growing interest in EC, using patient‐derived organotypic multicellular tumor spheroids and in vivo experiments.

Background Despite the growing interest in immunotherapeutic interventions for endometrial cancer (EC), the prevalence, phenotype, specificity and prognostic value of tumor infiltrating lymphocytes (TILs) in this tumor type remains unclear.Methods To better understand the role of TILs in EC, we analyzed the phenotypic traits of CD8+ and CD4+ EC-resident T cells from 47 primary tumors by high-dimensional flow cytometry. In addition, CD8+ and CD4+ TIL subpopulations were isolated based on the differential expression of programmed cell death protein-1 (PD-1) (negative, dim and high) and CD39 (positive or negative) by fluorescence activated cell sorting (FACS), expanded in vitro, and screened for autologous tumor recognition. We further investigated whether phenotypic markers preferentially expressed on CD8+ and CD4+ tumor-reactive TIL subsets were associated with the four distinct molecular subtypes of EC, tumor mutational burden and patient survival.Results We found that CD8+TILs expressing high levels of PD-1 (PD-1hi) co-expressed CD39, TIM-3, HLA-DR and CXCL13, as compared with TILs lacking or displaying intermediate levels of PD-1 expression (PD-1− and PD-1dim, respectively). Autologous tumor reactivity of sorted and in vitro expanded CD8+ TILs demonstrated that the CD8+PD-1dimCD39+ and PD-1hiCD39+ T cell subsets both contained tumor-reactive TILs and that a higher level of PD-1 expression was associated with increased CD39 and a superior frequency of tumor reactivity. With respect to CD4+ T conventional (Tconv) TILs, co-expression of inhibitory and activation markers was more apparent on PD-1hi compared with PD-1− or PD-1dim T cells, and in fact, it was the CD4+PD-1hi subpopulation that accumulated the antitumor T cells irrespective of CD39 expression. Most importantly, detection of CD8+PD-1hiCD39+ and CD4+PD-1hi tumor-reactive T-cell subsets, but also markers specifically expressed by these subpopulations of TILs, that is, PD-1hi, CD39, CXCL13 and CD103 by CD8+ TILs and PD-1hi and CXCL13 by CD4+ Tconv TILs, correlated with prolonged survival of patients with EC.Conclusions Our results demonstrate that EC are frequently infiltrated by tumor-reactive TILs, and that expression of PD-1hi and CD39 or PD-1hi can be used to select and expand CD8+ and CD4+ tumor-reactive TILs, respectively. In addition, biomarkers preferentially expressed on tumor-reactive TILs, rather than the frequency of CD3+, CD8+ and CD4+ lymphocytes, hold prognostic value suggesting their protective role in antitumor immunity.

Abstract Introduction Cervical cytology is a well‐stablished cervical cancer screening method. However, due to the anatomical continuity of the genital tract, it can also detect signs of endometrial disease. Our aim was to estimate the sensitivity of cervical cytology in endometrial cancer detection and prognosis in a large population over a 30‐year period in a large academic tertiary hospital in Spain. Methodology We performed a search for women diagnosed with endometrial cancer from 1990 to 2020, who were surgically treated and had a previous cervical cytology result. Information Technologies Department databases from Bellvitge University Hospital and the Screenwide case–control study's database were used. Cervical cytology results were classified as abnormal when squamous lesions, glandular atypia or malignant cells were identified. Results Overall, we evaluated 371 women with endometrial cancer and a documented cervical cytology performed within 3 years previous to surgical treatment. Overall, the sensitivity of cervical cytology for endometrial cancer detection was 25.6%. Several clinico‐pathological characteristics, such as non‐endometrioid histology and a higher stage, were correlated with higher sensitivity. Discussion We observed a low sensitivity of cervical cytology to effectively diagnose endometrial cancer. However, recent technological advances using genomics and epigenomics may offer a promising perspective to detect endometrial cancer with high sensitivity in these cervical specimens.

SMARCA4 is commonly inactivated in lung and ovarian cancers. Here the authors show that SMARCA4-deficient tumours have significantly reduced levels of the histone demethylases KDM6s and a strong dependency on these demethylases for tumour growth, so that they are vulnerable to KDM6s inhibition.

Abstract An open debate in antiangiogenic therapies is about their consequence on tumor invasiveness and metastasis, which is undoubtedly relevant for patients currently treated with antiangiogenics, such as renal cell carcinoma patients. To address, this we developed an extensive series of 27 patient biopsy‐derived orthotopic xenograft models (Ren‐PDOX) that represent inter‐patient heterogeneity. In specific tumors, antiangiogenics produced increased invasiveness and metastatic dissemination, while in others aggressiveness remained unchanged. Mechanistically, species‐discriminative RNA sequencing identified a tumor cell‐specific differential expression profile associated with tumor progression and aggressivity in TCGA RCC patients. Gene filtering using an invasion‐annotated patient series pinpointed two candidate genes, of which ALDH1A3 differentiated the pro‐invasive subtype of Ren‐PDOXs. Validation in an independent series of 15 antiangiogenic‐treated patients confirmed that pre‐treatment ALDH1A3 can significantly discriminate patients with pro‐aggressive response upon treatment. Overall, results confirm that effects of antiangiogenic drugs on tumor invasion and metastasis are heterogeneous and may profoundly affect the natural progression of tumors and promote malignancy. Furthermore, we identify a specific molecular biomarker that could be used to select patients that better benefit from treatment.

A drug used at the maximum tolerated dose can exert a strong selective pressure on cancer cells leading to resistance. In this study, the authors demonstrate the efficacy of using low dose of multiple drugs for preventing and treating resistance to EGFR tyrosine kinase inhibitors in NSCLC cells.

Abstract Mitochondrial metabolism and the generation of reactive oxygen species (ROS) contribute to the acquisition of DNA mutations and genomic instability in cancer. How genomic instability influences the metabolic capacity of cancer cells is nevertheless poorly understood. Here, we show that homologous recombination‐defective (HRD) cancers rely on oxidative metabolism to supply NAD+ and ATP for poly(ADP‐ribose) polymerase (PARP)‐dependent DNA repair mechanisms. Studies in breast and ovarian cancer HRD models depict a metabolic shift that includes enhanced expression of the oxidative phosphorylation (OXPHOS) pathway and its key components and a decline in the glycolytic Warburg phenotype. Hence, HRD cells are more sensitive to metformin and NAD+ concentration changes. On the other hand, shifting from an OXPHOS to a highly glycolytic metabolism interferes with the sensitivity to PARP inhibitors (PARPi) in these HRD cells. This feature is associated with a weak response to PARP inhibition in patient‐derived xenografts, emerging as a new mechanism to determine PARPi sensitivity. This study shows a mechanistic link between two major cancer hallmarks, which in turn suggests novel possibilities for specifically treating HRD cancers with OXPHOS inhibitors.

Abstract Inhibition of mTOR is the standard of care for lymphangioleiomyomatosis (LAM). However, this therapy has variable tolerability and some patients show progressive decline of lung function despite treatment. LAM diagnosis and monitoring can also be challenging due to the heterogeneity of symptoms and insufficiency of non‐invasive tests. Here, we propose monoamine‐derived biomarkers that provide preclinical evidence for novel therapeutic approaches. The major histamine‐derived metabolite methylimidazoleacetic acid (MIAA) is relatively more abundant in LAM plasma, and MIAA values are independent of VEGF‐D. Higher levels of histamine are associated with poorer lung function and greater disease burden. Molecular and cellular analyses, and metabolic profiling confirmed active histamine signaling and metabolism. LAM tumorigenesis is reduced using approved drugs targeting monoamine oxidases A/B (clorgyline and rasagiline) or histamine H1 receptor (loratadine), and loratadine synergizes with rapamycin. Depletion of Maoa or Hrh1 expression, and administration of an L‐histidine analog, or a low L‐histidine diet, also reduce LAM tumorigenesis. These findings extend our knowledge of LAM biology and suggest possible ways of improving disease management.

Background: The aim of this study was to test the feasibility and utility of developing patient-derived orthotopic xenograft (PDOX) models for patients with malignant peripheral nerve sheath tumors (MPNSTs) to aid therapeutic interventions in real time. Patient & Methods: A sporadic relapsed MPNST developed in a 14-year-old boy was engrafted in mice, generating a PDOX model for use in co-clinical trials after informed consent. SNP-array and exome sequencing was performed on the relapsed tumor. Genomics, drug availability, and published literature guided PDOX treatments. Results: A MPNST PDOX model was generated and expanded. Analysis of the patient’s relapsed tumor revealed mutations in the MAPK1, EED , and CDK2NA/B genes. First, the PDOX model was treated with the same therapeutic regimen as received by the patient (everolimus and trametinib); after observing partial response, tumors were left to regrow. Regrown tumors were treated based on mutations (palbociclib and JQ1), drug availability, and published literature (nab-paclitaxel; bevacizumab; sorafenib plus doxorubicin; and gemcitabine plus docetaxel). The patient had a lung metastatic relapse and was treated according to PDOX results, first with nab-paclitaxel, second with sorafenib plus doxorubicin after progression, although a complete response was not achieved and multiple metastasectomies were performed. The patient is currently disease free 46 months after first relapse. Conclusion: Our results indicate the feasibility of generating MPNST-PDOX and genomic characterization to guide treatment in real time. Although the treatment responses observed in our model did not fully recapitulate the patient’s response, this pilot study identify key aspects to improve our co-clinical testing approach in real time.

Antiangiogenic drugs are used clinically for treatment of renal cell carcinoma (RCC) as a standard first-line treatment. Nevertheless, these agents primarily serve to stabilize disease, and resistance eventually develops concomitant with progression. Here, we implicate metabolic symbiosis between tumor cells distal and proximal to remaining vessels as a mechanism of resistance to antiangiogenic therapies in patient-derived RCC orthoxenograft (PDX) models and in clinical samples. This metabolic patterning is regulated by the mTOR pathway, and its inhibition effectively blocks metabolic symbiosis in PDX models. Clinically, patients treated with antiangiogenics consistently present with histologic signatures of metabolic symbiosis that are exacerbated in resistant tumors. Furthermore, the mTOR pathway is also associated in clinical samples, and its inhibition eliminates symbiotic patterning in patient samples. Overall, these data support a mechanism of resistance to antiangiogenics involving metabolic compartmentalization of tumor cells that can be inhibited by mTOR-targeted drugs.

Understanding the mechanisms of cancer therapeutic resistance is fundamental to improving cancer care. There is clear benefit from chemotherapy in different breast cancer settings; however, knowledge of the mutations and genes that mediate resistance is incomplete. In this study, by modeling chemoresistance in patient-derived xenografts (PDXs), we show that adaptation to therapy is genetically complex and identify that loss of transcription factor 4 (TCF4; also known as ITF2) is associated with this process. A triple-negative BRCA1-mutated PDX was used to study the genetics of chemoresistance. The PDX was treated in parallel with four chemotherapies for five iterative cycles. Exome sequencing identified few genes with de novo or enriched mutations in common among the different therapies, whereas many common depleted mutations/genes were observed. Analysis of somatic mutations from The Cancer Genome Atlas (TCGA) supported the prognostic relevance of the identified genes. A mutation in TCF4 was found de novo in all treatments, and analysis of drug sensitivity profiles across cancer cell lines supported the link to chemoresistance. Loss of TCF4 conferred chemoresistance in breast cancer cell models, possibly by altering cell cycle regulation. Targeted sequencing in chemoresistant tumors identified an intronic variant of TCF4 that may represent an expression quantitative trait locus associated with relapse outcome in TCGA. Immunohistochemical studies suggest a common loss of nuclear TCF4 expression post-chemotherapy. Together, these results from tumor xenograft modeling depict a link between altered TCF4 expression and breast cancer chemoresistance.

[This corrects the article DOI: 10.1371/journal.pone.0132546.].

Abstract Malignant peripheral nerve sheath tumors (MPNSTs) are soft‐tissue sarcomas that can arise either sporadically or in association with neurofibromatosis type 1 (NF1). These aggressive malignancies confer poor survival, with no effective therapy available. We present the generation and characterization of five distinct MPNST orthoxenograft models for preclinical testing and personalized medicine. Four of the models are patient‐derived tumor xenografts (PDTX), two independent MPNSTs from the same NF1 patient and two from different sporadic patients. The fifth model is an orthoxenograft derived from an NF1‐related MPNST cell line. All MPNST orthoxenografts were generated by tumor implantation, or cell line injection, next to the sciatic nerve of nude mice, and were perpetuated by 7–10 mouse‐to‐mouse passages. The models reliably recapitulate the histopathological properties of their parental primary tumors. They also mimic distal dissemination properties in mice. Human stroma was rapidly lost after MPNST engraftment and replaced by murine stroma, which facilitated genomic tumor characterization. Compatible with an origin in a catastrophic event and subsequent genome stabilization, MPNST contained highly altered genomes that remained remarkably stable in orthoxenograft establishment and along passages. Mutational frequency and type of somatic point mutations were highly variable among the different MPNSTs modeled, but very consistent when comparing primary tumors with matched orthoxenografts generated. Unsupervised cluster analysis and principal component analysis (PCA) using an MPNST expression signature of ~1,000 genes grouped together all primary tumor–orthoxenograft pairs. Our work points to differences in the engraftment process of primary tumors compared with the engraftment of established cell lines. Following standardization and extensive characterization and validation, the orthoxenograft models were used for initial preclinical drug testing. Sorafenib (a BRAF inhibitor), in combination with doxorubicin or rapamycin, was found to be the most effective treatment for reducing MPNST growth. The development of genomically well‐characterized preclinical models for MPNST allowed the evaluation of novel therapeutic strategies for personalized medicine.

Carcinoma-associated fibroblasts (CAFs) are important contributors of microenvironment in determining the tumor’s fate. This study aimed to compare the influence of liver microenvironment and primary tumor microenvironment on the behavior of colorectal carcinoma. Conditioned medium (CM) from normal colonic fibroblasts (NCFs), CAFs from primary tumor (CAF-PT) or liver metastasis (CAF-LM) were obtained. We performed functional assays to test the influence of each CM on colorectal cell lines. Microarray and gene set enrichment analysis (GSEA) were performed in DLD1 cells cultured in matched CM. In DLD1 cells, CAF-LM CM compared with CAF-PT CM and NCF led to a more aggressive phenotype, induced the features of an epithelial-to-mesenchymal transition more efficiently, and stimulated migration and invasion to a greater extent. Sustained stimulation with CAF-LM CM evoked a transient G2/M cell cycle arrest accompanied by a reduction of apoptosis, inhibition of proliferation, and decreased viability of SW1116, SW620, SW480, DLD1, HT-29, and Caco-2 cells and provoked nonapoptotic cell death in those cells carrying KRAS mutations. Cells resistant to CAF-LM CM completely changed their morphology in an extracellular signal-regulated protein kinase-dependent process and depicted an increased stemness capacity alongside the Wnt pathway stimulation. The transcriptomic profile of DLD1 cells treated with CAF-LM CM was associated with Wnt and mitogen-activated protein kinase pathways activation in GSEA. Therefore, the liver microenvironment induces more efficiently the aggressiveness of colorectal cancer cells than other matched microenvironments do but secondarily evokes cell death. Resistant cells displayed higher stemness capacity.

Lymphangioleiomyomatosis (LAM) is a rare lung-metastasizing neoplasm caused by the proliferation of smooth muscle-like cells that commonly carry loss-of-function mutations in either the tuberous sclerosis complex 1 or 2 (TSC1 or TSC2) genes. While allosteric inhibition of the mechanistic target of rapamycin (mTOR) has shown substantial clinical benefit, complementary therapies are required to improve response and/or to treat specific patients. However, there is a lack of LAM biomarkers that could potentially be used to monitor the disease and to develop other targeted therapies. We hypothesized that the mediators of cancer metastasis to lung, particularly in breast cancer, also play a relevant role in LAM. Analyses across independent breast cancer datasets revealed associations between low TSC1/2 expression, altered mTOR complex 1 (mTORC1) pathway signaling, and metastasis to lung. Subsequently, immunohistochemical analyses of 23 LAM lesions revealed positivity in all cases for the lung metastasis mediators fascin 1 (FSCN1) and inhibitor of DNA binding 1 (ID1). Moreover, assessment of breast cancer stem or luminal progenitor cell biomarkers showed positivity in most LAM tissue for the aldehyde dehydrogenase 1 (ALDH1), integrin-ß3 (ITGB3/CD61), and/or the sex-determining region Y-box 9 (SOX9) proteins. The immunohistochemical analyses also provided evidence of heterogeneity between and within LAM cases. The analysis of Tsc2-deficient cells revealed relative over-expression of FSCN1 and ID1; however, Tsc2-deficient cells did not show higher sensitivity to ID1-based cancer inhibitors. Collectively, the results of this study reveal novel LAM biomarkers linked to breast cancer metastasis to lung and to cell stemness, which in turn might guide the assessment of additional or complementary therapeutic opportunities for LAM.

Nature Communications 5: Article number: 4608 (2014); Published: 3 April 2014; Updated: 2 November 2016 During the preparation of the PCR gel panels in Fig. 1b,c, duplicate or otherwise irrelevant lanes were excised; these excisions were not noted in the published figure as per the Nature journal policy.