Patient response after treatment of renal cell cancer (RCC) with systemic agents, which include various drug categories, is generally poor and unpredictable. In this context, the ideal drug administration includes tools to predict the sensitivity of the disease to therapy. The aim of this study was to systematically summarize the reports on the predictive value of the methylation status in the systemic therapy of RCC. Only original articles reporting on the association of promoter methylation with the response of patients or cell lines to systemic agents were included in this review. We applied PRISMA recommendations to the structure and methodology of this systematic review. Our literature search concluded with 31 articles conducted on RCC cell lines and patient tissues. The majority of the studies demonstrated a methylation-dependent response to systemic agents. This correlation suggests that the methylation pattern can be used as a predictive tool in the management of RCC with various classes of systemic agents. However, although methylation biomarkers show promise for predicting response, the evidence of such correlation is still weak. More studies on the gene methylation pattern in patients under systemic therapy and its correlation with different degrees of response are needed.

Breast cancer is the most common type of lethal cancer in women globally. Women have a 1 in 8 chance of developing breast cancer in their lifetime. Among the four primary molecular subtypes (luminal A, luminal B, HER2+, and triple-negative), HER2+ accounts for 20-25 % of all breast cancer and is rather aggressive. Although the treatment outcome of HER2+ breast cancer patients has been significantly improved with anti-HER2 agents, primary and acquired drug resistance present substantial clinical issues, limiting the benefits of HER2-targeted treatment. MicroRNAs (miRNAs) play a central role in regulating acquired drug resistance. miRNA are single-stranded, non-coding RNAs of around 20-25 nucleotides, known for essential roles in regulating gene expression at the post-transcriptional level. Increasing evidence has demonstrated that miRNA-mediated alteration of gene expression is associated with tumorigenesis, metastasis, and tumor response to treatment. Comprehensive knowledge of miRNAs as potential markers of drug response can help provide valuable guidance for treatment prognosis and personalized medicine for breast cancer patients.

MicroRNAs (miRNAs) are a group of highly conserved, short (18-25 nucleotide long) non-coding RNAs which play important functional roles in cellular differentiation, biological development, pathogenesis and disease susceptibility and have been linked to both tumorigenesis and the malignant progression of various cancers. miRNAs primarily exert their function through the negative regulation of their target gene\'s transcription via the specific recognition of their 3\' untranslated region. A single miRNA can regulate multiple target genes and most miRNAs are controlled by several factors. Recent studies have shown that microRNA-149 (miR-149) plays a pivotal role in the pathogenesis of digestive system cancers and may act as a potential diagnostic marker and therapeutic target. In this review, we summarize and discuss the most recent reports describing miR-149 in digestive system cancers, including its single nucleotide polymorphisms, expression levels, target genes, drug sensitivity and clinical significance.

Patient-derived xenograft (PDX) models are used as powerful tools for understanding cancer biology in PDX clinical trials and co-clinical trials. In this systematic review, we focus on PDX clinical trials or co-clinical trials for drug development in solid tumors and summarize the utility of PDX models in the development of anti-cancer drugs, as well as the challenges involved in this approach, following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Recently, the assessment of drug efficacy by PDX clinical and co-clinical trials has become an important method. PDX clinical trials can be used for the development of anti-cancer drugs before clinical trials, with their efficacy assessed by the modified response evaluation criteria in solid tumors (mRECIST). A few dozen cases of PDX models have completed enrollment, and the efficacy of the drugs is assessed by 1 × 1 × 1 or 3 × 1 × 1 approaches in the PDX clinical trials. Furthermore, co-clinical trials can be used for personalized care or precision medicine with the evaluation of a new drug or a novel combination. Several PDX models from patients in clinical trials have been used to assess the efficacy of individual drugs or drug combinations in co-clinical trials.

The aim of the present study was to summarize the clinical characteristics of nocardiosis caused by Nocardia otitidiscaviarum in order to improve the knowledge of nocardiosis. A case of dissemination nocardiosis caused by N. otitidiscaviarum in an immunocompetent host is reported and the associated literature reviewed. Informed consent for publication of this case report was provided by the patient. The present patient was a young immunocompetent man suffering from disseminated nocardiosis induced by infection with N. otitidiscaviarum. Following a poor response to β-lactam antibiotic, a combination of sulfonamide with minocycline was administered, which successfully ameliorated the symptoms. Previous studies published in English were retrieved from PubMed with \'Nocardia otitidiscaviarum\' used as the search keyword. A total of 23 articles were retrieved from the PubMed database, supporting the assertion that N. otitidiscaviarum is a rare Nocardia species. Among these 23 cases, there were 11 cases of lymphocutaneous (48%), 5 of pulmonary (22%), 2 of brain (9%) and 1 of pyothorax (4%) infection, and 4 cases of disseminated infections (17%). Analysis of the immune state of these patients demonstrated that 9 were immunocompetent (39%), 7 of whom had cutaneous infections (30%) with a predominant history of trauma (6/7), and 14 were immunosuppressed, 9 of whom were treated with prednisolone. Microbiology and histopathology were necessary in all cases for definite diagnosis. Among the 13 cases who underwent drug susceptibility testing, 10 cases were sensitive to trimethoprim-sulfamethoxazole (TMP-SMX) and 12 cases were sensitive to aminoglycoside. In conclusion, although N. otitidiscaviarum is one of the less commonly isolated species of Nocardia, it is capable of inducing localized or disseminated infection, even in an immunocompetent host. The majority of cases respond well to TMP-SMX and aminoglycoside, but the therapeutic action of cephalosporin is weak. Identification of bacteria and drug sensitivity tests for Nocardia is critical for guiding clinical treatment.

Despite a decline in the overall incidence of gastric cancer (GC), the disease remains the second most common cause of cancer-related death worldwide and is thus a significant global health problem. The best means of improving the survival of GC patients is to screen for and treat early lesions. However, GC is often diagnosed at an advanced stage and is associated with a poor prognosis. Current diagnostic and therapeutic strategies have not been successful in decreasing the global burden of the disease; therefore, the identification of reliable biomarkers for an early diagnosis, predictive markers of recurrence and survival and markers of drug sensitivity and/or resistance is urgently needed. The initiation and progression of GC depends not only on genetic alterations but also epigenetic changes, such as DNA methylation and histone modification. Aberrant DNA methylation is the most well-defined epigenetic change in human cancers and is associated with inappropriate gene silencing. Therefore, an increasing number of genes methylated at the promoter region have been targeted as possible biomarkers for different purposes, including early detection, classification, the assessment of the tumor prognosis, the development of therapeutic strategies and patient follow-up. This review article summarizes the current understanding and recent evidence regarding DNA methylation markers in GC with a focus on the clinical potential of these markers.