Identification of BRAF Inhibitor Resistance-associated lncRNAs Using Genome-scale CRISPR-Cas9 Transcriptional Activation Screening.

BACKGROUND/AIM: Approximately 50% of melanomas harbor the BRAF V600E mutation and targeted therapies using BRAF inhibitors improve patient outcomes. Nonetheless, resistance to BRAF inhibitors develops rapidly and remains a challenge in melanoma treatment. In this study, we attempted to isolate long noncoding RNAs (lncRNAs) involved in BRAF inhibitor resistance using a comprehensive screening method. MATERIALS AND METHODS: We used a CRISPR-Cas9 synergistic activation mediator (SAM) protein complex in a genome-scale transcriptional activation assay to screen for candidate lncRNA genes related to BRAF inhibitor resistance. Correlation analysis was performed between expression levels of isolated lncRNA genes and IC50 of dabrafenib in a BRAF-mutated melanoma cell line. Next, online databases were used to construct the lncRNA-miRNA-mRNA regulatory network. Finally, we evaluated the significance of the expression levels of these lncRNAs and mRNAs as biomarkers using clinical specimens. RESULTS: We isolated three BRAF inhibitor resistance-associated lncRNA genes, namely SNHG16, NDUFV2-AS1, and LINC01502. We constructed a lncRNA-miRNA-mRNA network of 13 nodes consisting of three lncRNAs, six miRNAs, and four mRNAs. The lncRNAs and target mRNAs from each regulatory axis significantly and positively correlated with each other. Finally, Kaplan-Meier analysis showed that higher expression levels of MITF, which was up-regulated by LINC01502, were significantly associated with worse prognosis in BRAF V600E-mutated melanoma. CONCLUSION: The identification of these BRAF inhibitor resistance-associated lncRNA genes at the genomic scale and the establishment of the lncRNA-miRNA-mRNA regulatory network provides new insights into the underlying mechanisms of BRAF inhibitor resistance in melanoma.

TP53 Signature Score Predicts Prognosis and Immune Response in Triple-negative Breast Cancer.

BACKGROUND/AIM: Triple-negative breast cancer (TNBC) is considered a heterogeneous disease and achieving a pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) is considered a surrogate biomarker of a favorable prognosis. Previously, the TP53 signature (TP53sig)-score, the expression profile of 33 genes, has been reported to predict the prognosis of all types of early-stage breast cancer. Herein, we analyzed whether the TP53sig-score can be used to subclassify a TNBC cohort and investigated the molecular biological characteristics of the higher TP53sig-score. PATIENTS AND METHODS: Publicly available data from TCGA (RNA-sequence) and METABRIC (microarray) and expression data from real clinical specimens (NanoString Technologies) were used to explore the prognosis and molecular features of TNBC. RESULTS: The high TP53sig-score group in the present study and the cohort in METABRIC tended to have a worse prognosis than the low TP53sig-score group (p=0.583 and 0.196, respectively). In both the pCR and non-pCR groups, the high TP53sig-score patients tended to have a poor prognosis (p=0.0739). Moreover, when the NAC response and TP53sig-score were combined, the five-year breast cancer-free rate among the four groups differed significantly (p=0.043). In addition, high TP53sig-score was related to gene ontology terms, such as "cell differentiation" and "innate immune response". Notably, this group had the potential to respond favorably to immunotherapy according to the tumor immune dysfunction and exclusion model. CONCLUSION: The combination of the response to NAC and the TP53sig-score in TNBC was able to predict an unfavorable prognosis. Furthermore, patients with a high TP53sig-score showed a favorable response to immunotherapy.

Effectiveness of Changing the Class of Molecularly Targeted Agent after Disease Progression during Initial Molecularly Targeted Therapy for Luminal Advanced/Metastatic Breast Cancer.

BACKGROUND: The emergence of molecularly targeted agents (MTAs) has altered the treatment landscape for hormone receptor-positive (HR+), human epidermal growth factor 2-negative (HER2-) advanced breast cancer (ABC) /metastatic breast cancer (MBC). Multiple guidelines recommend molecularly targeted therapy as first-line treatment for HR+/HER2- ABC/MBC. However, optimal treatment for disease progression during MTA therapy remains undetermined. This study evaluated the suitability of different MTA types for this patient subgroup. METHODS: In this retrospective study, we analyzed the electronic health records of 56 patients with HR+/HER2- ABC/MBC receiving treatment with palbociclib, abemaciclib, or everolimus in our center between April 2014 and June 2021. RESULTS: Overall, 39, 14, and 35 regimens using palbociclib, abemaciclib, and everolimus, respectively, were identified. Three and 53 patients were premenopausal and postmenopausal, respectively. MTAs were included in the 1st-11th lines of treatment. Time to failure (TTF) was significantly different among the three MTAs. In contrast, TTF did not significantly differ among the 50 regimens that included CDK4/6 inhibitors, with/without prior mTOR inhibitor use, and the 35 regimens that included mTOR inhibitors, with/without prior CDK4/6 inhibitor use. CONCLUSIONS: The sequential use of different MTA classes did not affect the TTF of another MTA. mTOR inhibitor + exemestane is a favorable treatment option after CDK4/6 inhibitor + hormone therapy, and CDK4/6 inhibitor + hormone therapy is suitable for patients previously treated with mTOR inhibitor + exemestane. Although this study was retrospective and conducted at a single center, the present findings are useful for treatment selection in clinical practice.

Elevation of the Prognostic Factor Plasma Fibrinogen Reflects the Immunosuppressive Tumor Microenvironment in Esophageal Squamous Cell Carcinoma.

INTRODUCTION: Despite previous reports on the clinical significance of plasma fibrinogen (FNG) levels as a prognostic indicator of ESCC, its underlying mechanism remains unclear. This study aimed to validate the prognostic impact of plasma FNG levels and clarify its relationship with primary tumors in patients with esophageal squamous cell carcinoma (ESCC). METHODS: The prognostic impact of FNG was evaluated in patients with ESCC who underwent esophagectomy between 2000 and 2019. The RNA sequencing of the primary ESCC site, which was from pre-operative biopsy, was performed, followed by immune profile characterization using an immunogram. Those profiles were assessed via the immunohistochemical staining of tumor-associated macrophages (TAMs) and clinical response to nivolumab. RESULTS: Multivariate analysis identified FNG as a significant prognostic factor in ESCC. The immunogram suggested an immunosuppressive tumor environment in the high-FNG group. Immunostaining with the TAM markers CD163 and CD204, revealed that the high-FNG group had significantly higher number of TAMs compared with the low-FNG group. The immunosuppressive characteristics were clinically validated in patients with metastatic ESCC; those who had elevated FNG levels showed poor response to nivolumab. CONCLUSION: This study successfully validated the prognostic impact of plasma FNG levels in an expanded cohort with ESCC. Accordingly, our findings showed that increased plasma FNG reflects an immunosuppressive tumor microenvironment that facilitates tumor progression and poor responses to nivolumab.

The MDM2 and CDKN2A Copy-number-variation Influence the TP53-signature-score in Wild-type TP53 Luminal Type Breast Cancer.

BACKGROUND/AIM: The TP53-signature is a multi-gene signature that can predict TP53 structural mutations. It has presented remarkable ability to predict the prognosis of early-stage breast cancer. However, some samples presented discordance with the signature status and structure status. We aimed to investigate whether the mRNA expression levels or copy number variation (CNV) of MDM2 and CDKN2A influence the TP53-signature-score, subtype classification, and prognosis prediction in TP53 wild-type, luminal type early-stage breast cancer samples. MATERIALS AND METHODS: We selected TP53 wild-type, luminal type early-stage breast cancer samples from The Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) cohorts. Then, we analyzed the correlation between the TP53-signature-score and mRNA expression levels or CNV of MDM2 and CDKN2A. RESULTS: The samples with MDM2 copy number (CN) amplification or those with CDKN2A CN deep deletion presented higher TP53-signature-score. Moreover, samples with MDM2 CN amplification or those with CDKN2A CN deep deletion had more characteristics of the luminal B type. In addition, they showed lower estrogen response early score, which correlated with response to endocrine therapy in breast cancer. However, MDM2 and CDKN2A mRNA expression did not present the same tendency. Furthermore, samples with MDM2 CN amplification or those with CDKN2A CN deep deletion had a worse prognosis in METABRIC cohort. CONCLUSION: The MDM2 or CDKN2A CNV may be useful for classifying subtypes and predicting prognosis more accurately in TP53 wild-type, luminal type early-stage breast cancer patients.

Molecular Targeted Therapy for Hormone Receptor-Positive, Human Epidermal Growth Factor 2-Negative Metastatic Breast Cancer in Clinical Practice.

BACKGROUND: The emergence of molecular targeted therapies (MTTs) has altered the treatment landscape for hormone receptor-positive (HR+), human epidermal growth factor 2-negative (HER2-) metastatic breast cancer (MBC). The objective of this study was to describe treatment patterns, clinical outcomes, and safety profiles for patients with HR+/HER2- MBC treated with palbociclib, abemaciclib, or everolimus in clinical practice. METHODS: Forty-five patients with HR+/HER2- MBC were enrolled; 40 received MTT as the third line or later and 5 received MTT as the first/second line. The results were compared with those of clinical trials. RESULTS: Median overall progression-free survival (PFS) was 5.3 months (95% confidence interval [CI] 2.8-8.4), and PFS was similar for patients receiving first/second line (5.5 months, 95% CI 1.8-) and third line or later (5.1 months, 95% CI 2.8-9.4) treatments. Eleven patients continued with the same regimen for >1 year; treatment is ongoing for 15 patients. In 23 patients (51%), everolimus was administered before cyclin-dependent kinase (CDK) 4/6 inhibitors. The most frequent grade 3 or worse adverse event (AE) with CDK4/6 inhibitors was neutropenia, whereas grade 3 or worse AEs with everolimus were Pneumocystis pneumonia, sepsis, and stomatitis. CONCLUSIONS: MTT was mostly used in third or later lines, and PFS was similar for patients receiving first/second line and third or later line treatments. However, this study included heavily treated patients and a small number of cases. Treatment options should consider maximal patient benefit, as indicated by the results of clinical trials.

Comprehensive analysis of the homeobox family genes in breast cancer demonstrates their similar roles in cancer and development.

BACKGROUND: The homeobox (HOX) family consists of 39 genes whose expressions are tightly controlled and coordinated within the family, during development. We performed a comprehensive analysis of this gene family in cancer settings. METHODS: Gene correlation analysis was performed using breast cancer data available in The Cancer Genome Atlas (TCGA) and data from the patients admitted to our hospital. We also analyzed the data of normal breast tissue (GSE20437). We next collected gene expression and prognosis data of breast cancer patients (GSE11121, GSE7390, GSE3494, and GSE2990) and performed unsupervised hierarchal clustering by the HOX gene expression pattern and compared prognosis. We additionally performed this analysis to leukemia (available in TCGA) and sarcoma (GSE20196) data. RESULTS: Gene correlation analysis showed that the proximal HOX genes exhibit strong interactions and are expressed together in breast cancer, similar to the expression observed during development. However, in normal breast tissue, less interactions were observed. Breast cancer microarray meta-data classified by the HOX gene expression pattern predicted the prognosis of luminal B breast cancer patients (p = 0.016). Leukemia (p = 0.00016) and sarcoma (p = 0.018) presented similar results. The Wnt signaling pathway, one of the major upstream signals of HOX genes in development, was activated in the poor prognostic group. Interestingly, poor prognostic cancer presented stronger correlation in the gene family compared to favorable prognostic cancer. CONCLUSION: Comprehensive analysis of the HOX family demonstrated their similar roles in cancer and development, and indicated that the strong interaction of HOX genes might be specific to malignancies, especially in the case of poor prognostic cancer.

Identification of the mutation signature of the cancer genome caused by irradiation.

BACKGROUND AND PURPOSE: Ionising radiation causes mutations in the genomes of tumour cells and serves as a potent treatment for cancer. However, the mutation signatures in the cancer genome following ionising radiation have not been documented. MATERIALS AND METHODS: We established an in vitro experimental system to analyse the presence of de novo mutations in the cancer genome of irradiated (60 Gy/20 fr/4 weeks) oesophageal cancer cell lines. Subsequently, we performed whole-genome, chromatin immunoprecipitation, and RNA sequencing using untreated and irradiated samples to assess the damage to the genome caused by radiation and understand the underlying mechanism. RESULTS: The irradiated cancer cells exhibited hotspots for the de novo 8502-12966 single nucleotide variants and 954-1,331 indels on the chromosome. These single nucleotide variants primarily originated from double-stranded break repair errors, as determined using mutation signature analysis. The hotspots partially overlapped with the sites of H3K9 trimethylation, which are regions characterised by a weak capacity for double-stranded break repair. CONCLUSION: This study highlights the signature and underlying mechanism of radiation on the cancer genome.

A novel scoring method based on RNA-Seq immunograms describing individual cancer-immunity interactions.

Because of the complexity of cancer-immune system interactions, combinations of biomarkers will be required for predicting individual patient responses to treatment and for monitoring combination strategies to overcome treatment resistance. To this end, the "immunogram" has been proposed as a comprehensive framework to capture all relevant immunological variables. Here, we developed a method to convert transcriptomic data into immunogram scores (IGS). This immunogram includes 10 molecular profiles, consisting of innate immunity, priming and activation, T cell response, interferon γ (IFNG) response, inhibitory molecules, regulatory T cells, myeloid-derived suppressor cells (MDSCs), recognition of tumor cells, proliferation, and glycolysis. Using genes related to these 10 parameters, we applied single-sample gene set enrichment analysis (ssGSEA) to 9417 bulk RNA-Seq data from 9362 cancer patients with 29 different solid cancers in The Cancer Genome Atlas (TCGA). Enrichment scores were z-score normalized (Z) for each cancer type or the entire TCGA cohort. The IGS was defined by the formula IGS = 3 + 1.5 × Z so that patients would be well distributed over a range of scores from 1 to 5. The immunograms constructed in this way for all individual patients in the entire TCGA cohort can be accessed at "The RNA-Seq based Cancer Immunogram Web" (https://yamashige33.shinyapps.io/immunogram/).

Assessment of Predictive Biomarkers of the Response to Pazopanib Based on an Integrative Analysis of High-grade Soft-tissue Sarcomas: Analysis of a Tumor Sample from a Responder and Patients with Other Soft-tissue Sarcomas.

BACKGROUND: Soft-tissue sarcomas are a rare group of malignant tumors that usually are treated with surgical excision and radiation therapy, but recently, pazopanib, an oral tyrosine kinase inhibitor, has been used in patients with metastases who do not respond to standard chemotherapy regimens. Based on patients with advanced soft-tissue sarcomas who had received prior chemotherapy, several clinical studies have reported the survival and sensitivity (approximately 5% to 10% sensitive) of patients with soft-tissue sarcomas treated with pazopanib. Recently, next-generation sequencing (NGS) technologies have been used to provide a wide genetic information and to develop personalized medicine in cancer treatment. However, there are few reports and no genetic analyses of patients with soft-tissue sarcomas who had a complete response (CR) to pazopanib. QUESTIONS/PURPOSES: We described the clinicopathologic features of a patient with a rare, advanced soft-tissue sarcoma who achieved a CR to pazopanib treatment. Furthermore, integrative analyses using NGS and arrays were performed to elucidate characteristic alterations, including gene mutations, copy number changes, and protein expression that were associated with response to pazopanib. Additionally, functional analyses consisting of in vitro and in vivo assays were also performed to elucidate whether the identified alterations were associated with oncogenic abilities and drug responses. METHODS: In a sample from a 70-year-old woman with an advanced soft-tissue sarcoma treated for 1 month with 800 mg of oral pazopanib daily, CT scans demonstrated a CR to treatment. To our knowledge, there have been no patients with soft-tissue sarcomas among several clinical trials of pazopanib that have achieved a CR and therefore, our patient is considered to be extremely rare. We performed an integrative analysis including whole-exome sequencing, transcriptome sequencing, and phosphorylation profiling of receptor tyrosine kinases (RTK) using tumor samples from a patient with a CR matched to normal samples. From here on we will refer to this patient as having a CR, although a short term high-grade partial response may be more accurate. These analyses were performed using NGS and the phosphoreceptor tyrosine kinase (phospho-RTK) array. As a validation study, we also performed target sequencing using three samples from patients with long-term stable disease and two samples from patients with progressive disease who responded to pazopanib treatment. In addition, characteristic gene alterations that were identified according to the response to pazopanib in one patient with a CR, in three patients with long-term stable disease, and in 27 patients with high-grade soft-tissue sarcomas with different histologic subtypes and different responses to pazopanib were verified by quantitative real-time polymerase chain reaction. We conducted a focus formation assay to evaluate the transforming activities of these genomic alterations. RESULTS: In the patient with a CR to pazopanib, we identified several somatic mutations including Fms related receptor tyrosine kinase 1 (FLT1) p.G38S, platelet-derived growth factor receptor alpha (PDGFRA) p.T83S, and platelet-derived growth factor receptor beta (PDGFRB) exon 13 skipping. Amplification at chromosome 12q13-14 encompassing GLI family zinc finger 1 (GLI1) and cyclin-dependent kinase-4 (CDK4) was also detected. Furthermore, an elevated PDGFRB phosphorylation level was observed in the tumor. In target sequencing analyses in five patients, one of three patients with long-term stable disease had 12q13-14 amplification. The mRNA expression of GLI1, CDK4, and pazopanib targets including PDGFRA, PDGFRB, vascular endothelial growth factor receptor (VEGFR)1-3, and stem cell factor receptor (KIT) in samples from the patient with a CR, and 27 patients with high-grade soft-tissue sarcomas was verified. The expression of GLI1 was characteristically increased in the patient with a CR and in those with long-term stable disease relative to other patients with soft-tissue sarcomas. Overexpression of GLI1 showed strong transforming potential in 3T3 cells. Moreover, the overexpression of GLI1 upregulated the expression of the PDGFRB protein and promoted phosphorylation, which was dose-dependently inhibited by pazopanib. However, inhibition of GLI1-induced transformation by pazopanib was limited in the focus formation assay; therefore, mechanisms other than PDGFRB activation may contribute to transformation. CONCLUSIONS: We identified several gene alterations that might be associated with a CR and long-term stable disease in patients who received pazopanib for advanced soft-tissue sarcomas. We therefore believe that this distinct molecular profile warrants further investigation to identify predictive biomarkers of the response to pazopanib. CLINICAL RELEVANCE: Our findings identify molecular mechanisms that possibly explain the high sensitivity of soft-tissue sarcomas to pazopanib and may lead to the development of predictive biomarkers and novel therapies in patients with this and other types of soft-tissue sarcomas.

A novel diagnostic system to evaluate epidermal growth factor receptor impact as a prognostic and therapeutic indicator for lung adenocarcinoma.

Many driver pathways for cancer cell proliferation have been reported. Driver pathway activation is often evaluated based on a single hotspot mutation such as EGFR L858R. However, because of complex intratumoral networks, the impact of a driver pathway cannot be predicted based on only a single gene mutation. Here, we developed a novel diagnostic system named the "EGFR impact score" which is based on multiplex mRNA expression profiles, which can predict the impact of the EGFR pathway in lung cancer cells and the effect of EGFR-tyrosine kinase inhibitors on malignancy. The EGFR impact score indicated robust predictive power for the prognosis of early-stage lung cancer because this score can evaluate the impact of the EGFR pathway on the tumor and genomic instability. Additionally, the molecular features of the poor prognostic group resembled those of biomarkers associated with immune checkpoint inhibitors. The EGFR impact score is a novel prognostic and therapeutic indicator for lung adenocarcinoma.

Identification of a Modified HOXB9 mRNA in Breast Cancer.

First identified as a developmental gene, HOXB9 is also known to be involved in tumor biological processes, and its aberrant expression correlates with poor prognosis of various cancers. In this study, we isolated a homeodomain-less, novel HOXB9 variant (HOXB9v) from human breast cancer cell line-derived mRNA. We confirmed that the novel variant was produced from variationless HOXB9 genomic DNA. RT-PCR of mRNA isolated from clinical samples and reanalysis of publicly available RNA-seq data proved that the new transcript is frequently expressed in human breast cancer. Exogenous HOXB9v expression significantly enhanced the proliferation of breast cancer cells, and gene ontology analysis indicated that apoptotic signaling was suppressed in these cells. Considering that HOXB9v lacks key domains of homeobox proteins, its behavior could be completely different from that of the previously described variationless HOXB9. Because none of the previous studies on HOXB9 have considered the presence of HOXB9v, further research analyzing the two transcripts individually is warranted to re-evaluate the true role of HOXB9 in cancer.

[A Case of Pediatric Soft Tissue Sarcoma with LMNA-NTRK1 Gene Fusion Treated with Larotrectinib under Single Patient Expanded Access System].

Tropomyosin-related kinase(TRK)fusion proteins are oncogenic drivers in multiple tumors in adults and children.Larotrectinib, an orally administered selective TRK inhibitor approved in the US, exhibits inhibitory activity against tumors harboring TRK fusions and is well tolerated.Here, we report the case of an 8-year-old female child with recurrence of an NTRK fusion low-grade sarcoma treated with larotrectinib monotherapy.The patient previously underwent resection of low-grade sarcoma in the right brachialis at 6 years of age, but local recurrence occurred after 16 months.As re-operation likely required amputation, larotrectinib was commenced at a dose of 100 mg BID.Complete radiographic remission was achieved after 3 months.There were no adverse events attributed to larotrectinib treatment.After dosing for 6 months, we performed local resection, confirming pathological complete remission.The drug was stopped, and the patient showed no evidence of relapse at 4 months after resection.In this case, larotrectinib was obtained using Single Patient Expanded Access under the FDA.In this paper, we also discuss the issues faced while accessing unapproved drugs in the precision medicine era in Japan.

[An Effective Treatment of Relapsed Leiomyosarcoma with Fourth-Line Trabectedin].

A 56-year-old women underwent retroperitoneal leiomyosarcoma resection in December 2011. In July 2015, CT showed multiple liver metastases, and she received first-line chemotherapy treatment with doxorubicin. After 2 courses of doxorubicin, her performance status deteriorated; therefore, she was treated with pazopanib as second-line chemotherapy. PFS with pazopanib was 5 months and that with eribulin was 2.5 months. She was then treated with trabectedin as fourth-line chemotherapy from July 2016. The liver metastases reduced, and the disease was controlled for 1 year and 6 months following administration of trabectedin. We continue to treat this patient with trabectedin, and no serious side effects have been observed.

Multicenter experience with large panel next-generation sequencing in patients with advanced solid cancers in Japan.

BACKGROUND: Application of next-generation DNA sequencing (NGS) has recently become increasingly common in the field of clinical oncology in several countries around the world. In Japan also, a system for applying NGS to routine clinical practice is gradually being established. During this process, we introduced in Japan the tumor-profiling MSK-IMPACT (Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets) assay. METHODS: We present here our initial experience with the use of MSK-IMPACT in 68 patients selected from two institutions in Japan between June 2016 and October 2017. RESULTS: MSK-IMPACT sequencing was successful and yielded results in specimens obtained from 64 of the 68 patients, representing an overall assay success rate of 94.1%. The top three cancer types tested were endometrial cancer (17.2%), pancreatic cancer (15.6%) and colorectal cancer (12.5%). Evaluation of the clinical actionability of the genetic alterations revealed that 25.0% of patients (n = 16) harbored at least one actionable alteration. However, enrolling the patients in a genomically matched clinical trial was difficult, mainly because most clinical trials are limited to tumors arising from a specific organ/site. One patient with microsatellite instability-high status, as determined by MSK-IMPACT, was treated with pembrolizumab and showed partial response. CONCLUSIONS: Although tumor profiling by NGS and administration of genomically matched therapy is a promising strategy, because of its high cost, we need to consider how we can fit it into the Japanese medical system. Towards this end, we believe that it is important to share our initial experience for furthering precision medicine in Japan.

Radiotherapy increases plasma levels of tumoral cell-free DNA in non-small cell lung cancer patients.

We investigated the plasma levels of tumor-specific cell-free DNA (cfDNA) in 17 stage I-II (early) and IV (advanced) non-small cell lung cancer (NSCLC) patients who underwent radiotherapy. Digital polymerase chain reaction (PCR) and targeted sequencing showed that total and tumor-specific cfDNA levels increased in response to radiotherapy in both early- and advanced-stage NSCLC patients. We detected high copy numbers of epidermal growth factor receptor mutations (L858R and T790M) in the cfDNA samples from stage IV NSCLC patients who underwent stereotactic body radiation therapy to treat brain metastasis related to tyrosine kinase inhibitor (TKI) treatment failure. In conclusion, our study demonstrates that radiotherapy increases tumoral cfDNA levels in the plasma and shows potential to serve as an indicator for diagnosing drug-resistant tumor-related gene mutations in early-stage NSCLC patients or those undergoing molecular targeted therapy.

Correction: Radiotherapy increases plasma levels of tumoral cell-free DNA in non-small cell lung cancer patients.

[This corrects the article DOI: 10.18632/oncotarget.25053.].

Identification and characterization of a novel adenomatous polyposis coli mutation in adult pancreatoblastoma.

During next generation sequencing (NGS) analysis, many missense mutations were found in a well-known oncogene, many of which were variant of uncertain significance mutations. We recently treated an adult patient with pancreatoblastoma by chemotherapy. Using an NGS cancer panel, we found a previously unreported missense mutation in the 1835 codon of the adenomatous polyposis coli (APC) gene. We also found a heterogeneous mutation in the 1835 codon of the APC gene in the patient's germline by Sanger sequencing. Although this patient did not have a history of familial adenomatous polyposis, functional analysis suggested the R1835G mutant APC showed attenuated repression of Wnt/ß-catenin signaling activity. This is the first report showing a novel APC missense mutation involved in the onset of adult pancreatoblastoma.

Molecular and clinical features of the TP53 signature gene expression profile in early-stage breast cancer.

PURPOSE: TP53 signature has a robust predictive performance for prognosis in early-stage breast cancer, but the experiment that reported this relied on public microarray data and fresh-frozen samples. Before TP53 signature can be used in a clinical setting, a simple and low-cost diagnostic system using formalin-fixed paraffin-embedded (FFPE) samples is needed. New treatments based on the biological characteristics of TP53 signature are expected to follow. EXPERIMENTAL DESIGN: TP53 signature was evaluated in 174 FFPE early breast cancer specimens using digital quantification via the nCounter technique (NanoString). Patients were classified as TP53 signature mutant type (n = 64) or wild type (n = 110). Predictive power of TP53 signature was compared with those of other gene expression signatures in 153 fresh-frozen samples of the same cohort by RNA-seq. The molecular features of TP53 signature were elucidated using TCGA omics data and RNA-seq data to explore new therapeutic strategies for patients with TP53 signature mutant type. RESULTS: TP53 signature was a strong predictor of prognosis and was also more accurate than other gene expression signatures and independent of other clinicopathological factors. TCGA data analysis showed that risk score of TP53 signature was an index of chromosomal and genomic instability and that TP53 signature mutant type was associated with higher PD-L1 expression, variation in copy numbers, and numbers of somatic mutations. CONCLUSIONS: TP53 signature as diagnosed using the nCounter system is not only a robust predictor of prognosis but also a potential predictor of responsiveness to immune checkpoint inhibitors.