Com probe implemented STexS II greatly enhances specificity in SARS-CoV-2 variant detection.

The initial introduction of utilizing double helix structural oligonucleotides known as SNP typing with excellent specificity (STexS) in a standard PCR greatly improved the detection of single nucleotide polymorphisms (SNP) by enhancing amplification rates of primer-matching strands and interrupting mismatched strands by constant instability of kinetics regarding alignment attaching and detaching. The model was beneficial overall in detecting SNP variants consisting of large amounts of wildtype strands such as EGFR mutation genotyping for early detection of non-small cell lung cancer. While the STexS PCR is advantageous in detecting SNPs and biomarkers, limitations were yet observed. Despite the ability to detect variants 10 times more effective than a typical amplification-refractory mutation system PCR, it could only perform optimally in DNA concentrations around 101 ~ 105. To further enhance STexS specificity to perform detecting viral-RNA variants such as the infamous SARS-CoV-2, a novel improvement of the regular TaqMan Probe using Com-probes to inhibit high copy wild targets and amplify low copy mutant targets. By introducing the novel STexS II, omicron variants of SARS-CoV-2 were able to be successfully detected in high concentrations of normal genes.

Inclusion of double helix structural oligonucleotide (STexS) results in an enhance of SNP specificity in PCR.

Genetic mutations such as single nucleotide polymorphisms (SNP) are known as one of the most common forms which related to various genetic disorders and cancers. Among of the methods developed for efficient detection of such SNP, polymerase chain reaction (PCR) methods are widely used worldwide for its cost and viable advantages. However, the technique to discriminate small amounts of SNP mixed in abundant normal DNA is incomplete due to intrinsic technical problems of PCR such as amplification occurring even in 3'mismatched cases because of high enzyme activity of DNA polymerases. To overcome the issue, specifically designed PCR platform, STexS (SNP typing with excellent specificity) using double stranded oligonucleotides was implemented as a means to emphasize the amplification of SNP templates by decreasing unwanted amplification of 3'mismatched DNA copies. In this study, the results indicate several EGFR mutations were easily detected specifically utilizing the STexS platform. Further trials show the novel method works effectively to discriminate mutations in not only general allele specific (AS)-PCRs, but also amplification refractory mutation system (ARMS)-PCR. The STexS platform will give aid in PCRs targeting potential SNPs or genetically mutated biomarkers in human clinical samples.

Noncanonical immune response to the inhibition of DNA methylation by Staufen1 via stabilization of endogenous retrovirus RNAs.

DNA-methyltransferase inhibitors (DNMTis), such as azacitidine and decitabine, are used clinically to treat myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Decitabine activates the transcription of endogenous retroviruses (ERVs), which can induce immune response by acting as cellular double-stranded RNAs (dsRNAs). Yet, the posttranscriptional regulation of ERV dsRNAs remains uninvestigated. Here, we find that the viral mimicry and subsequent cell death in response to decitabine require the dsRNA-binding protein Staufen1 (Stau1). We show that Stau1 directly binds to ERV RNAs and stabilizes them in a genome-wide manner. Furthermore, Stau1-mediated stabilization requires a long noncoding RNA TINCR, which enhances the interaction between Stau1 and ERV RNAs. Analysis of a clinical patient cohort reveals that MDS and AML patients with lower Stau1 and TINCR expressions exhibit inferior treatment outcomes to DNMTi therapy. Overall, our study reveals the posttranscriptional regulatory mechanism of ERVs and identifies the Stau1-TINCR complex as a potential target for predicting the efficacy of DNMTis and other drugs that rely on dsRNAs.

Common plasma protein marker LCAT in aggressive human breast cancer and canine mammary tumor.

Breast cancer is one of the most frequently diagnosed cancers. Although biomarkers are continuously being discovered, few specific markers, rather than classification markers, representing the aggressiveness and invasiveness of breast cancer are known. In this study, we used samples from canine mammary tumors in a comparative approach. We subjected 36 fractions of both canine normal and mammary tumor plasmas to highperformance quantitative proteomics analysis. Among the identified proteins, LCAT was selectively expressed in mixed tumor samples. With further MRM and Western blot validation, we discovered that the LCAT protein is an indicator of aggressive mammary tumors, an advanced stage of cancer, possibly highly metastatic. Interestingly, we also found that LCAT is overexpressed in high-grade and lymph-node-positive breast cancer in silico data. We also demonstrated that LCAT is highly expressed in the sera of advanced-stage human breast cancers within the same classification. In conclusion, we identified a possible common plasma protein biomarker, LCAT, that is highly expressed in aggressive human breast cancer and canine mammary tumor. [BMB Reports 2020; 53(12): 664-669].

Analysis of opposing histone modifications H3K4me3 and H3K27me3 reveals candidate diagnostic biomarkers for TNBC and gene set prediction combination.

Breast cancer encompasses a major portion of human cancers and must be carefully monitored for appropriate diagnoses and treatments. Among the many types of breast cancers, triple negative breast cancer (TNBC) has the worst prognosis and the least cases reported. To gain a better understanding and a more decisive precursor for TNBC, two major histone modifications, an activating modification H3K4me3 and a repressive modification H3K27me3, were analyzed using data from normal breast cell lines against TNBC cell lines. The combination of these two histone markers on the gene promoter regions showed a great correlation with gene expression. A list of signature genes was defined as active (highly enriched H3K4me3), including NOVA1, NAT8L, and MMP16, and repressive genes (highly enriched H3K27me3), IRX2 and ADRB2, according to the distribution of these histone modifications on the promoter regions. To further enhance the investigation, potential candidates were also compared with other types of breast cancer to identify signs specific to TNBC. RNA-seq data was implemented to confirm and verify gene regulation governed by the histone modifications. Combinations of the biomarkers based on H3K4me3 and H3K27me3 showed the diagnostic value AUC 93.28% with P-value of 1.16e-226. The results of this study suggest that histone modification analysis of opposing histone modifications may be valuable toward developing biomarkers and targets for TNBC. [BMB Reports 2020; 53(5): 266-271].

Transcriptome Signatures of Canine Mammary Gland Tumors and Its Comparison to Human Breast Cancers.

Breast cancer (BC)/mammary gland carcinoma (MGC) is the most frequently diagnosed and leading cause of cancer-related mortality in both women and canines. To better understand both canine MGC and human BC-specific genes, we sequenced RNAs obtained from eight pairs of carcinomas and adjacent normal tissues in dogs. By comprehensive transcriptome analysis, 351 differentially expressed genes (DEGs) were identified in overall canine MGCs. Based on the DEGs, comparative analysis revealed correlation existing among the three histological subtypes of canine MGC (ductal, simple, and complex) and four molecular subtypes of human BC (HER2+, ER+, ER&HER2+, and TNBC). Eight DEGs shared by all three subtypes of canine MGCs had been previously reported as cancer-associated genes in human studies. Gene ontology and pathway analyses using the identified DEGs revealed that the biological processes of cell proliferation, adhesion, and inflammatory responses are enriched in up-regulated MGC DEGs. In contrast, fatty acid homeostasis and transcription regulation involved in cell fate commitment were down-regulated in MGC DEGs. Moreover, correlations are demonstrated between upstream promoter transcripts and DEGs. Canine MGC- and subtype-enriched gene expression allows us to better understand both human BC and canine MGC, yielding new insight into the development of biomarkers and targets for both diseases.

A Case of Organizing Hematoma in a Maxillary Sinus After Reconstruction of a Blow-Out Fracture.

A 36-year-old man presented because of nasal obstruction, rhinorrhea, and postnasal drip. The patient had undergone reconstruction of a blow-out fracture of the orbital floor 12 years before and had sinusitis that likely had resulted from implant migration into the maxillary sinus. The inflammation was successfully resolved, and the implant was removed through a minimally invasive endoscopic sinus surgery technique. On pathologic examination, an organizing hematoma was identified as the cause of the lesion. Pre- and postoperational paranasal sinus computed tomography images were taken to compare the anatomy of the sinus before and following surgery.

Salvage of a Necrotic Flap.

OBJECTIVE: To report the case of a 68-year-old woman with a skin basal cell carcinoma on the nasal dorsum. After excision, the soft tissue defect was reconstructed using a rectangular advancement flap. However, 2 days later skin necrosis was observed. This report was issued to advise how to avoid and manage skin necrosis after regional flap placement. METHODS: This is a retrospective study. RESULTS: Superficial skin necrosis recovered completely after proper medical management. CONCLUSIONS: When planning an advancement flap, care should be taken to design the flap properly and not to injure flap blood supply to avoid skin necrosis. In addition, surgeons should be aware of the difference between superficial and total flap necrosis.