Exploring molecular tools for transformation and gene expression in the cultivated edible mushroom Agrocybe aegerita.

Agrocybe aegerita is a cultivated edible mushroom in numerous countries, which also serves as a model basidiomycete to study fruiting body formation. Aiming to create an easily expandable customised molecular toolset for transformation and constitutive gene of interest expression, we first created a homologous dominant marker for transformant selection. Progeny monokaryons of the genome-sequenced dikaryon A. aegerita AAE-3 used here were identified as sensitive to the systemic fungicide carboxin. We cloned the wild-type gene encoding the iron-sulphur protein subunit of succinate dehydrogenase AaeSdi1 including its up- and downstream regions, and introduced a single-point mutation (His237 to Leu) to make it confer carboxin resistance. PEG-mediated transformation of protoplasts derived from either oidia or vegetative monokaryotic mycelium with the resulting carboxin resistance marker (CbxR) plasmid pSDI1E3 yielded carboxin-resistant transformants in both cases. Plasmid DNA linearised within the selection marker resulted in transformants with ectopic multiple insertions of plasmid DNA in a head-to-tail repeat-like fashion. When circular plasmid was used, ectopic single integration into the fungal genome was favoured, but also gene conversion at the homologous locus was seen in 1 out of 11 analysed transformants. Employing CbxR as selection marker, two versions of a reporter gene construct were assembled via Golden Gate cloning which allows easy recombination of its modules. These consisted of an eGFP expression cassette controlled by the native promoter PAaeGPDII and the heterologous terminator Tnos, once with and once without an intron in front of the eGFP start codon. After protoplast transformation with either construct as circular plasmid DNA, GFP fluorescence was detected with either transformants, indicating that expression of eGFP is intron-independent in A. aegerita. This paves the way for functional genetics approaches to A. aegerita, e.g., via constitutive expression of fruiting-related genes.

Recurrent epistaxis leading to diagnosis of primary sinonasal melanoma.

A 48-year-old man presented to urgent care with recurrent epistaxis over 6 months. Initially, nosebleeds were controlled with packing or cautery. Ultimately, he was referred to ear, nose and throat department and underwent nasal endoscopy which revealed polypoid tissue. A biopsy of the polyp showed non-specific inflammation with no evidence of malignancy. Follow-up maxillofacial CT revealed a large mass lesion in the right maxillary sinus, right nasal fossa, much of the ethmoids and right sphenoid, with destruction of adjacent bony structures. MRI revealed a mass in the right nasal cavity with extension into the ethmoid and anterior sphenoid sinus, anterior cranial fossa and medial orbits. Staging CT discovered metastatic disease in the adrenal glands and lymphadenopathy in the neck. The patient underwent endoscopic sinus surgery with debulking and tissue diagnosis of malignant melanoma. He completed radiation therapy to sinus and was subsequently enrolled in a clinical trial. Most recent imaging revealed complete metabolic response on positron emission tomography.

An Unusual Clinical Presentation of Gastrointestinal Metastasis From Invasive Lobular Carcinoma of Breast.

Introduction. We present an unusual case of metastatic lobular breast carcinoma. Typical areas of metastasis include bone, gynecological organs, peritoneum, retroperitoneum, and gastrointestinal (GI) tract, in order of frequency. With regard to GI metastasis, extrahepatic represents a rare site. Case. Two years after being diagnosed with invasive lobular breast carcinoma, a 61-year-old female complained of 3 months of nonspecific abdominal pain and diarrhea. A colonoscopy revealed 5 tubular adenomatous polyps in the ascending and transverse colon. Contrast computed tomography (CT) of the abdomen and pelvis was done 7 months after the colonoscopy to further evaluate persistent diarrhea. The CT results were consistent with infectious or inflammatory enterocolitis. Despite conservative management, symptoms failed to improve and a repeat diagnostic colonoscopy was obtained. Random colonic biopsies revealed metastatic high-grade adenocarcinoma of the colon. Discussion. Metastatic lobular breast carcinoma to the GI tract can distort initial interpretation of endoscopic evaluation with lesions mimicking inflammation. The interval between discovery of GI metastasis and diagnosis of lobular breast cancer can vary widely from synchronous to 30 years; however, progression is most often much sooner. Nonspecific symptoms and subtle appearance of metastatic lesions may confound the diagnosis. A high index of suspicion is needed for possible metastatic spread to the GI tract in patients with a history of invasive lobular breast carcinoma. Perhaps, patients with nonspecific GI symptoms should have an endoscopic examination with multiple random biopsies as invasive lobular carcinoma typically mimics macroscopic changes consistent with colitis.