Mixed Adenosquamous Cell Carcinoma of the Prostate with Paired Sequencing on the Primary and Liver Metastasis.

This report aims to shed light on the intricate challenges encountered during the diagnosis and treatment of an uncommon variant of prostate cancer-mixed adenosquamous cell carcinoma of the prostate. Prostate cancers of this nature pose distinctive diagnostic and therapeutic dilemmas due to their rarity and complex histological composition. We present a case of a 63-year-old man with metastatic prostate cancer, featuring adenocarcinoma with squamous cell differentiation, who underwent a multimodal treatment approach. The patient responded to first-line carboplatin, docetaxel, and androgen deprivation therapy, followed by androgen receptor pathway inhibitor (ARPI) maintenance. However, disease progression led to radiation therapy and a subsequent switch to Lutetium (177Lu) vipivotide tetraxetan after chemotherapy challenges. Comprehensive genetic profiling revealed shared mutations in the prostate and liver lesions, emphasizing the role of targeted therapies. Prostate-specific membrane antigen (PSMA)-targeted therapy resulted in a notable PSA decline. This case highlights the evolving treatment landscape for rare prostate cancers, integrating genetic insights for tailored interventions. In conclusion, squamous cell carcinoma (SCC) of the prostate is rare, emphasizing the imperative for enhanced comprehension in diagnosis and management. Our case suggests the potential efficacy of ARPI and PSMA-targeted therapies. Our findings advocate for a more nuanced approach to the management of this rare prostate cancer variant, leveraging genomic insights for personalized treatment strategies. This exploration serves as a foundation for further research and clinical considerations in addressing the challenges posed by mixed adenosquamous cell carcinoma of the prostate.

Gene Expression Analysis for Uterine Cervix and Corpus Cancer Characterization.

The analysis of gene expression quantification data is a powerful and widely used approach in cancer research. This work provides new insights into the transcriptomic changes that occur in healthy uterine tissue compared to those in cancerous tissues and explores the differences associated with uterine cancer localizations and histological subtypes. To achieve this, RNA-Seq data from the TCGA database were preprocessed and analyzed using the KnowSeq package. Firstly, a kNN model was applied to classify uterine cervix cancer, uterine corpus cancer, and healthy uterine samples. Through variable selection, a three-gene signature was identified (VWCE, CLDN15, ADCYAP1R1), achieving consistent 100% test accuracy across 20 repetitions of a 5-fold cross-validation. A supplementary similar analysis using miRNA-Seq data from the same samples identified an optimal two-gene miRNA-coding signature potentially regulating the three-gene signature previously mentioned, which attained optimal classification performance with an 82% F1-macro score. Subsequently, a kNN model was implemented for the classification of cervical cancer samples into their two main histological subtypes (adenocarcinoma and squamous cell carcinoma). A uni-gene signature (ICA1L) was identified, achieving 100% test accuracy through 20 repetitions of a 5-fold cross-validation and externally validated through the CGCI program. Finally, an examination of six cervical adenosquamous carcinoma (mixed) samples revealed a pattern where the gene expression value in the mixed class aligned closer to the histological subtype with lower expression, prompting a reconsideration of the diagnosis for these mixed samples. In summary, this study provides valuable insights into the molecular mechanisms of uterine cervix and corpus cancers. The newly identified gene signatures demonstrate robust predictive capabilities, guiding future research in cancer diagnosis and treatment methodologies.

Clinicopathological and molecular characteristics of colorectal adenosquamous carcinoma in an Asian population.

BACKGROUND: Adenosquamous carcinoma is a rare sub-type of colorectal cancer with a poor prognosis. Little is known about its clinicopathological and molecular characteristics in Asian populations. This study aimed to investigate these features in a cohort of patients with adenosquamous carcinoma in the colorectum. METHODS: Tumor cases pathologically diagnosed with colorectal adenosquamous carcinoma were retrieved from the Sixth Affiliated Hospital, Sun Yat-sen University tissue archive between December 2012 and June 2020. Clinicopathological features, molecular characteristics, and oncology outcomes were analyzed. RESULTS: Among 18,139 cases of colorectal cancer, 11 were diagnosed with adenosquamous carcinoma, providing an incidence rate of 0.061%. The median overall survival (OS) was 14 months, and the expected 3-year OS rate was 29.6%. As of October 14, 2022, four cases had local recurrence and five had distant metastasis. KRAS gene mutations were found in four of seven patients (57.1%), and three out of eleven (27.3%) patients had mismatch repair-deficient (dMMR) tumors. CONCLUSIONS: Adenosquamous carcinoma is associated with a poor prognosis. Compared to other sub-types of colorectal cancer, a higher proportion of patients with dMMR and KRAS mutations were observed. These findings suggested that more patients with adenosquamous carcinoma could benefit from targeted therapies, such as immunotherapy.

Complete pathologic response to neoadjuvant icotinib in stage IIIA EGFR-mutant lung adenosquamous carcinoma: A case report.

RATIONALE: Radical surgery offers the best chance of cure, it is critical to expand surgery opportunities for patients with early-stage lung cancer to prolong overall survival. However, evidence is still limited regarding the application of neoadjuvant therapy with EGFR-tyrosine kinase. PATIENT: The patient reported here was a 53-year-old woman with right lower lung adenosquamous carcinoma. DIAGNOSES: The lung cancer was staged as T3N1M0. Tumor genotype disclosed EGFR Exon19 c.2235-2249de p.E746-A750del. INTERVENTION: After neoadjuvant treatment with icotinib, she underwent thoracotomy and achieved pathological complete response. OUTCOMES: She is currently receiving adjuvant icotinib therapy without recurrence or metastasis during 18-month follow-up. LESSONS: Our case indicated that the feasibility of neoadjuvant icotinib in EGFR-mutant lung adenosquamous carcinoma.

Genetic analysis of low-grade adenosquamous carcinoma of the breast progressing to high-grade metaplastic carcinoma.

PURPOSE: Low-grade adenosquamous carcinoma (LGASC) is a rare type of metaplastic carcinoma of the breast (MBC) with an indolent clinical course. A few LGASC cases with high-grade transformation have been reported; however, the genetics underlying malignant progression of LGASC remain unclear. METHODS: We performed whole-genome sequencing analysis on five MBCs from four patients, including one case with matching primary LGASC and a lymph node metastatic tumor consisting of high-grade MBC with a predominant metaplastic squamous cell carcinoma component (MSC) that progressed from LGASC and three cases of independent de novo MSC. RESULTS: Unlike de novo MSC, LGASC and its associated MSC showed no TP53 mutation and tended to contain fewer structural variants than de novo MSC. Both LGASC and its associated MSC harbored the common GNAS c.C2530T:p.Arg844Cys mutation, which was more frequently detected in the cancer cell fraction of MSC. MSC associated with LGASC showed additional pathogenic deletions of multiple tumor-suppressor genes, such as KMT2D and BTG1. Copy number analysis revealed potential 18q loss of heterozygosity in both LGASC and associated MSC. The frequency of SMAD4::DCC fusion due to deletions increased with progression to MSC; however, chimeric proteins were not detected. SMAD4 protein expression was already decreased at the LGASC stage due to unknown mechanisms. CONCLUSION: Not only LGASC but also its associated high-grade MBC may be genetically different from de novo high-grade MBC. Progression from LGASC to high-grade MBC may involve the concentration of driver mutations caused by clonal selection and inactivation of tumor-suppressor genes.

A patient with a lung adenosquamous carcinoma harboring a de novo T790M mutation and huge nonbacterial vegetative growths successfully treated with osimertinib: A case report.

Nonbacterial thrombotic endocarditis (NBTE) is a rare condition; sterile vegetations attach to heart valves. NBTE is typically found in patients with malignancies or autoimmune disorders. Although surgical interventions are sometimes performed, the appropriate indication and timing are still unclear. Here, we describe a 72-year-old woman diagnosed with adenosquamous carcinoma of the lung. She was initially diagnosed as pT2aN0M0 and underwent RUL lobectomy. After nine months, lung cancer recurred, and she underwent treatment with cytotoxic chemotherapy. However, images showed progression after only one month. Rebiopsy revealed she had comutation of de novo EGFR L858R and T790M. Treatment was changed to gefitinib. After one month, she experienced loss of consciousness. Brain magnetic resonance imaging (MRI) showed multiple lesions resembling infarctions or metastases. Chest computed tomography (CT) revealed progression. Osimertinib was prescribed and she underwent echocardiography to rule out the possibility of a cardiogenic embolism. Surprisingly, severe mitral regurgitation and a massive vegetation on the mitral valve were found. Cardiologists recommended surgery due to the severity of the embolic event and valve dysfunction, but it was decided to continue antibiotics, osimertinib, and anticoagulants instead of surgery due to the patient's poor general condition and the possibility of NBTE. Six weeks later, the patient's condition markedly improved and echocardiography revealed a marked reduction in vegetation size. Clinicians should be aware that targeted therapy can be effective in treating severe cancer complications, such as NBTE, as evidenced by the successful treatment of lung cancer with osimertinib. This option should be considered, particularly for elderly lung cancer patients, before resorting to surgery as a first-line treatment for NBTE.

Colorectal adenosquamous carcinoma: genomic profiling of a rare histotype of colorectal cancer.

Colorectal adenosquamous carcinoma (ASC) is exceedingly rare, comprising less than 0.1% of all colorectal malignancies, and is characterized by an aggressive disease course, with a higher metastatic rate and worse outcome than conventional colorectal adenocarcinoma. A comprehensive molecular profile of this group of neoplasms is still lacking. A total of 22 cases of colorectal ASCs (with 22 primary lesions and 7 metastases matched with 4 primaries) were subject to NGS targeting 67 cancer-related genes (VariantPlex solid tumor; Archer). Mismatch repair (MMR), p53, and V600EBRAF status were also investigated by immunohistochemistry. In 28 of 29 (96.6%) ASC samples, at least one single-nucleotide variant (SNV) or copy number variation (CNV) was detected. Among the 22 primary tumors, the most frequently mutated genes were TP53 (59.1%), APC (40.9%), KRAS (27.3%), BRAF (13.6%), and GNAS (9.1%). Only 1/22 (4.5%) primary ASC was MMR-deficient (MMRd) and harbored a BRAF mutation. Limited differences in SNVs were observed between primary and metastatic diseases. This study sheds light on the molecular landscape of colorectal ASCs. According to our data, the genomic profile of colorectal ASC is similar to that of conventional colorectal carcinoma, with significant druggable genetic alterations. Further studies are required to understand the more aggressive clinical behavior of this neoplasm.

Partial response in non-resectable adenosquamous carcinoma of the pancreas with high tumour mutation burden treated with gemcitabine, nab-paclitaxel and pembrolizumab.

A previously healthy man in his 60s was diagnosed with a rare histological subtype of pancreatic cancer, adenosquamous carcinoma. After somatic mutation profiling, it was found that the tumour had microsatellite instability status high and a high tumour mutational burden. The patient was started on combination therapy with gemcitabine, nab-paclitaxel and pembrolizumab. Tumour size and biomarkers showed a dramatic response eventually leading to the patient being transitioned to maintenance therapy with pembrolizumab. The patient has demonstrated continued response since the start of the treatment. This is the first report in the literature showing a sustained response in this type of neoplasm that was treated with a checkpoint inhibitor, and thus adds to the evidence supporting universal somatic testing in all pancreatic cancers for a tailored approach to therapy.

Cervical Gastric-type Adenosquamous Carcinoma: Case Report of a Rare Neoplasm Associated With a BRCA1 Pathogenic Variant.

Gastric-type adenocarcinoma is the commonest human papillomavirus (HPV)-independent adenocarcinoma of the cervix. We report a rare case of a primary cervical gastric-type adenocarcinoma with malignant squamous elements (gastric-type adenosquamous carcinoma) in a 64-yr-old female. This is only the third report of a cervical gastric-type adenosquamous carcinoma. The tumor was p16 negative and molecular studies for HPV were negative. Next-generation sequencing showed pathogenic variants in BRCA1 and KRAS , as well as variants of unknown significance in CDK12 and ATM and homozygous deletion of CDKN2A/CDKN2B . Pathologists should be aware that not all cervical adenosquamous carcinomas are HPV-associated and the term gastric-type adenosquamous carcinoma is recommended when malignant squamous elements are present within a gastric-type adenocarcinoma. In reporting this case, we discuss the differential and the possible therapeutic options raised by the presence of pathogenic variants in BRCA1 .

Development of an adenosquamous carcinoma histopathology - selective lung metastasis model.

Preclinical tumor models with native tissue microenvironments provide essential tools to understand how heterogeneous tumor phenotypes relate to drug response. Here we present syngeneic graft models of aggressive, metastasis-prone histopathology-specific NSCLC tumor types driven by KRAS mutation and loss of LKB1 (KL): adenosquamous carcinoma (ASC) and adenocarcinoma (AC). We show that subcutaneous injection of primary KL; ASC cells results in squamous cell carcinoma (SCC) tumors with high levels of stromal infiltrates, lacking the source heterogeneous histotype. Despite forming subcutaneous tumors, intravenously injected KL;AC cells were unable to form lung tumors. In contrast, intravenous injection of KL;ASC cells leads to their lung re-colonization and lesions recapitulating the mixed AC and SCC histopathology, tumor immune suppressive microenvironment and oncogenic signaling profile of source tumors, demonstrating histopathology-selective phenotypic dominance over genetic drivers. Pan-ERBB inhibition increased survival, while selective ERBB1/EGFR inhibition did not, suggesting a role of the ERBB network crosstalk in resistance to ERBB1/EGFR. This immunocompetent NSCLC lung colonization model hence phenocopies key properties of the metastasis-prone ASC histopathology, and serves as a preclinical model to dissect therapy responses and metastasis-associated processes.

Single-cell sequencing reveals heterogeneity between pancreatic adenosquamous carcinoma and pancreatic ductal adenocarcinoma with prognostic value.

Pancreatic adenosquamous carcinoma (ASPC) is a rare subtype of pancreatic cancer with lethal malignancy, and few studies have focused on the heterogeneity of ASPC. Here, we performed a single-cell sequencing procedure on pancreatic tumor tissue from an ASPC patient and a patient with high-grade intraductal papillary mucinous neoplasm (IPMN). Through the combined analysis of single-cell sequencing data from five pancreatic ductal adenocarcinoma (PDAC) patients, one IPMN patient, and one ASPC patient in a public database, we identified 11 main types of cells, including macrophages, B cells, cancer stem cells, ductal cells, fibroblasts, endo/stellate cells, neutrophils, acinar cells, T cells, natural killer (NK) cells, dendritic cells, and mast cells. Then, the different characteristics and differentiation paths of the immune microenvironment among IPMN, ASPC, and PDAC in macrophages, T cells, and cancer-associated fibroblasts (CAFs) were identified through multiple bioinformatics analyses. Two novel special cancer-associated fibroblasts were identified as nCAFs and imCAFs. Then, cancer cells in duct cells were identified using the infercnv software. Two ASPC-specific subgroups of cancer cells with squamous cell features were identified. Finally, the identified specific CAFs and cancer cells were mapped to TCGA-PAAD cohort through the cibersoftx software. All of these identified subgroups were calculated to have a significant prognostic value in pancreatic cancer patients. These findings will promote the clinical application of single-cell sequencing data of pancreatic cancer and deepen our understanding of ASPC.

Single-cell RNA-sequencing dissects cellular heterogeneity and identifies two tumor-suppressing immune cell subclusters in HPV-related cervical adenosquamous carcinoma.

The intratumor heterogeneity of human papillomavirus (HPV)-related cervical cancer remains poorly defined. We performed single-cell RNA sequencing on 18 046 individual cells derived from two HPV-related cervical adenosquamous carcinoma samples to analyze the transcriptional heterogeneity of both epithelial and immune constituents, identifying seven epithelial (Epi1-7) and 11 immune subclusters. Based on expression of known cervical cancer markers, Epi1-2 primarily displayed features of adenocarcinoma, whereas Epi3-6 were instead characterized by features of squamous carcinoma. Our analyses also revealed that hypoxia and Kirsten rat sarcoma viral oncogene signaling were highly represented within Epi1; metabolic pathways mediating glycolysis and oxidative phosphorylation were enriched in Epi2-4; while Epi5 was enriched in p53 pathway components and features of epithelial-mesenchymal transition. Moreover, CD8+ FGFBP2+ T cells and FGFBP2+ natural killer cells were found to display high levels of cytotoxic effectors (GZMA, GZMB, GNLY, and PRF1) and low levels of inhibitory markers (PDCD1, TIGIT, and CTLA4), such that tumor infiltration by these populations was positively associated with survival in a cohort of n = 165 patients with HPV-related cervical cancer from The Cancer Genome Atlas database (p = 0.017 and 0.014, respectively). These results shed new light on the intratumor heterogeneity of HPV-related cervical adenosquamous carcinoma, which will help to refine diagnostic and treatment approaches.

Neoadjuvant ceritinib treatment in ALK-rearranged locally advanced adenosquamous carcinoma: A case report.

Here, we first report a case of neoadjuvant ceritinib for locally advanced lung adenosquamous carcinoma. In this study, a locally advanced adenosquamous carcinoma (ASC) patient with EML4-ALK fusion who achieved a partial response with neoadjuvant ceritinib treatment after a cycle of neoadjuvant chemotherapy did not show significant efficacy. A complete surgical resection was performed with mild adhesions and a small amount of bleeding intraoperatively. The EML4-ALK fusion was detected by targeted next-generation sequencing (NGS) in both pretreatment biopsy and the postoperative tissue specimens with a dramatic decrease in the allele frequency (26.2% [pre]-2.3% [post]). Pathological examination of the postoperative specimens indicated a diagnosis of ASC but the proportions of adenocarcinoma and squamous cell carcinoma cells in the primary lung tumor and metastatic lymph node site were different, suggesting the various responses to ceritinib. Thus, with the case presented here, we provide the clinical evidence for ALK-positive locally advanced ASC patients benefiting from neoadjuvant ceritinib treatment with a tolerable safety profile, whereas further cohort studies of the efficacy and safety of neoadjuvant ceritinib in such patients are needed.

Mucoepidermoid carcinoma (MEC) and adenosquamous carcinoma (ASC), the same or different entities?

Mucoepidermoid carcinoma (MEC) and adenosquamous carcinoma (ASC) have overlapping histopathological appearances and sites of occurrence, which may cause diagnostic difficulty impacting subsequent treatment. We conducted a systematic review of the scientific literature to determine whether molecular alterations were sufficiently different in MEC and ASC to aid in classifying the two entities. We searched Medline, Embase and Web of Science for studies reporting molecular determinations of ASC and/or MEC and screened retrieved records for eligibility. Two independent researchers reviewed included studies, assessed methodological quality and extracted data. Of 8623 identified records, 128 articles were included for analysis: 5 which compared the two tumors in the same investigation using the same methods and 123 which examined the tumors separately. All articles, except one were case series of moderate to poor methodological quality. The 5 publications examining both tumors showed that 52/88 (59%) MEC and 0% of 110 ASC had rearrangement of the MAML2 gene as detected by FISH and/or RT-PCR, but did not investigate other genes. In the entire series MEC had MAML2 gene rearrangement in 1337/2009 (66.6%) of tumors studied. The articles examining tumors separately found that MEC had mutations in EGFR (11/329 cases, 3.3%), KRAS (11/266, 4.1%) and ERBB2 (9/126, 7.1%) compared with ASC that had mutations in EGFR (660/1705, 38.7%), KRAS (143/625, 22.9%) and ERBB2 (6/196, 3.1%). The highest level of recurrent mutations was in pancreatic ASC where (108/126, 85.7%) reported mutations in KRAS. The EGFR mutations in ASC were similar in number and kind to those in lung adenocarcinoma. By standards of systematic review methodology and despite the large number of retrieved studies, we did not find adequate evidence for a distinctive molecular profile of either MEC or ASC that could definitively aid in its classification, especially in histologically difficult cases that are negative for MAML2 rearrangement. The case series included in this review indicate the relevance of MAML2 rearrangement to support the diagnosis of MEC, findings that should be confirmed by additional research with adequate study design.

A phase II trial of the super-enhancer inhibitor Minnelide™ in advanced refractory adenosquamous carcinoma of the pancreas.

Adenosquamous carcinoma of the pancreas (ASCP) is a very rare and highly aggressive variant of pancreatic ductal adenocarcinoma, accounting for 0.5-4% of all pancreatic cancer cases in the USA. Current data indicate that epigenetic changes and MYC overexpression lead to squamous transdifferentiation of pancreatic tumor cells and development of ASCP. Minnelide™, an oral anti-super-enhancer drug that inhibits MYC expression in preclinical models of ASCP, has demonstrated safety in a phase I study. We describe the design for a phase II, open-label, single-arm trial of Minnelide in patients with advanced refractory ASCP.

Adenosquamous carcinoma of the pancreas (ASCP) is a rare and highly aggressive variant of pancreatic cancer, with limited treatment options. Changes in activation of DNA elements called super-enhancers drive the growth of ASCP. Minnelide™ is an oral drug that blocks the super-enhancer network and is safe to give to patients with advanced cancer. This trial is designed to determine whether Minnelide can shrink tumors in patients with ASCP who have already received at least one previous treatment for their cancer.  Clinical Trial Registration: NCT04896073 (ClinicalTrials.gov).

Bioinformatics Analysis of mRNAs and miRNAs for Identifying Potential Biomarkers in Lung Adenosquamous Carcinoma.

Background: Lung adenosquamous carcinoma (LASC) is a special type of lung cancer. LASC is a malignant tumor with strong aggressiveness and a poor prognosis. Previous studies have revealed that microRNAs (miRNAs) are widely involved in the development of tumors by targeting mRNA. This study is aimed at identifying the key mRNAs and miRNAs of LASC and constructing miRNA-mRNA networks for deeply comprehending the latent molecular mechanisms. Methods: mRNA dataset (GSE51852) and miRNA dataset (GSE51853) were extracted and downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) were picked out by the GEO2R web tool. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses were conducted in the DAVID database. The protein-protein interaction (PPI) network was performed and analyzed by using the STRING database and Cytoscape software, respectively. TransmiR v2.0 was applied to predict potential transcription factors of miRNAs. The target genes of DEMs were predicted in the miRWalk database. Results: In comparison to normal tissues, a total of 1458 DEGs (511 upregulated and 947 downregulated) and 13 DEMs (5 upregulated and 8 downregulated) were screened out in LASC tissues. The PPI network of the DEGs displayed five key modules and seventeen hub genes. Six target genes of the DEMs were predicted, and five essential miRNA-mRNA regulatory pairs were established. Ensuingly, CENPF, one of the target genes, was also the hub genes of GSE51852, which was obtained from MCODE and cytoHubba and regulated by hsa-miR-205. Conclusions: We constructed the miRNA-mRNA regulatory pairs, which are helpful to study the potential regulatory mechanisms and find out promising diagnosis biomarkers and therapeutic targets for LASC.

Single-cell transcriptomics reveals heterogeneous progression and EGFR activation in pancreatic adenosquamous carcinoma.

Pancreatic adenosquamous carcinoma (PASC) - a rare pathological pancreatic cancer (PC) type - has a poor prognosis due to high malignancy. To examine the heterogeneity of PASC, we performed single-cell RNA sequencing (scRNA-seq) profiling with sample tissues from a healthy donor pancreas, an intraductal papillary mucinous neoplasm, and a patient with PASC. Of 9,887 individual cells, ten cell subpopulations were identified, including myeloid, immune, ductal, fibroblast, acinar, stellate, endothelial, and cancer cells. Cancer cells were divided into five clusters. Notably, cluster 1 exhibited stem-like phenotypes expressing UBE2C, ASPM, and TOP2A. We found that S100A2 is a potential biomarker for cancer cells. LGALS1, NPM1, RACK1, and PERP were upregulated from ductal to cancer cells. Furthermore, the copy number variations in ductal and cancer cells were greater than in the reference cells. The expression of EREG, FCGR2A, CCL4L2, and CTSC increased in myeloid cells from the normal pancreas to PASC. The gene sets expressed by cancer-associated fibroblasts were enriched in the immunosuppressive pathways. We demonstrate that EGFR-associated ligand-receptor pairs are activated in ductal-stromal cell communications. Hence, this study revealed the heterogeneous variations of ductal and stromal cells, defined cancer-associated signaling pathways, and deciphered intercellular interactions following PASC progression.

NTRK fusion-positive colorectal cancer in Japanese population.

ALK, ROS1 and NTRK fusions are involved in the tumorigenesis of various organs, including colorectal cancer. This study aims to clarify the prevalence of these fusions in colorectal cancer in the Japanese population. Immunohistochemical analysis of 1012 specimens of colorectal cancer revealed two NTRK-positive cases (0.2%) whereas no ALK- or ROS1-positive cases were identified. Reverse transcription polymerase chain reaction (RT-PCR) detected an LMNA-NTRK1 fusion in a case of adenosquamous carcinoma and a TPM3-NTRK1 fusion in a case of tubular adenocarcinoma. Both NTRK1 fusion-positive cases lacked activating mutations in KRAS and BRAF and were mismatch repair-deficient with loss of MLH1 and PMS2 expression and MLH1 promoter methylation. Our results show that receptor tyrosine kinase fusions are rare but present in colorectal cancers in Japanese patients, with a prevalence similar to that reported in other countries.

miR-31 Displays Subtype Specificity in Lung Cancer.

miRNA rarely possess pan-oncogenic or tumor-suppressive properties. Most miRNAs function under tissue-specific contexts, acting as either tumor suppressors in one tissue, promoting oncogenesis in another, or having no apparent role in the regulation of processes associated with the hallmarks of cancer. What has been less clear is the role of miRNAs within cell types of the same tissue and the ability within each cell type to contribute to oncogenesis. In this study, we characterize the role of one such tissue-specific miRNA, miR-31, recently identified as the most oncogenic miRNA in lung adenocarcinoma, across the histologic spectrum of human lung cancer. Compared with normal lung tissue, miR-31 was overexpressed in patient lung adenocarcinoma, squamous cell carcinoma, and large-cell neuroendocrine carcinoma, but not small-cell carcinoma or carcinoids. miR-31 promoted tumor growth in mice of xenografted human adenocarcinoma and squamous cell carcinoma cell lines, but not in large- or small-cell carcinoma lines. While miR-31 did not promote primary tumor growth of large- and small-cell carcinoma, it did promote spontaneous metastasis. Mechanistically, miR-31 altered distinct cellular signaling programs within each histologic subtype, resulting in distinct phenotypic differences. This is the first report distinguishing diverse functional roles for this miRNA across the spectrum of lung cancers and suggests that miR-31 has broad clinical value in human lung malignancy. SIGNIFICANCE: These findings demonstrate the oncogenic properties of miR-31 in specific subtypes of lung cancer and highlight it as a potential therapeutic target in these subtypes. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/8/1942/F1.large.jpg.

The origins and consequences of UPF1 variants in pancreatic adenosquamous carcinoma.

Pancreatic adenosquamous carcinoma (PASC) is an aggressive cancer whose mutational origins are poorly understood. An early study reported high-frequency somatic mutations affecting UPF1, a nonsense-mediated mRNA decay (NMD) factor, in PASC, but subsequent studies did not observe these lesions. The corresponding controversy about whether UPF1 mutations are important contributors to PASC has been exacerbated by a paucity of functional studies. Here, we modeled two UPF1 mutations in human and mouse cells to find no significant effects on pancreatic cancer growth, acquisition of adenosquamous features, UPF1 splicing, UPF1 protein, or NMD efficiency. We subsequently discovered that 45% of UPF1 mutations reportedly present in PASCs are identical to standing genetic variants in the human population, suggesting that they may be non-pathogenic inherited variants rather than pathogenic mutations. Our data suggest that UPF1 is not a common functional driver of PASC and motivate further attempts to understand the genetic origins of these malignancies.

Cancer is a group of complex diseases in which cells grow uncontrollably and spread into surrounding tissues and other parts of the body. All types of cancers develop from changes ­ or mutations ­ in the genes that affect the pathways involved in controlling the growth of cells. Different cancers possess unique sets of mutations that affect specific genes, and often, it is difficult to determine which of them play the most important role in a particular type of cancer. For example, pancreatic adenosquamous carcinoma, a rare and aggressive form of pancreatic cancer, is a devastating disease with a poor chance of survival ­ patients rarely live longer than one year after diagnosis. While the cells of this particular cancer display distinct features that separate them from other forms of pancreatic cancer, the genetic causes of these features are unclear. Using new technologies, some researchers have reported mutations in a 'quality control' gene called 'UPF1', which is responsible for destroying faulty forms of genetic material. However, subsequent studies did not find such mutations. To clarify the role of UPF1 in pancreatic adenosquamous carcinoma, Polaski et al. used mouse and human cancer cells with UPF1 mutations and monitored their effects on tumour growth and the development of features unique to this disease. Polaski et al. first injected mice with mouse pancreatic cancer cells containing mutations in UPF1 (mutated cells) and cancer cells without. Both groups of mice developed pancreatic tumours but there was no difference in tumour growth between the mutated and non-mutated cells, and neither cell type displayed distinct features. The researchers then generated human mutated cells, which were also found to lack any specific characteristics. Further analysis showed that the mutations did not stop UPF1 from working, in fact, over 40% of these mutations occurred naturally in humans without causing cancer. This suggests that UPF1 does not seem to be involved in pancreatic adenosquamous carcinoma. Further investigation is needed to illuminate key genetic players in the development of this type of cancer, which will be vital for improving treatments and outcomes for patients suffering from this disease.