Identification of a Distinct miRNA Regulatory Network in the Tumor Microenvironment of Transformed Mycosis Fungoides

Diagnostic significance of dysregulated miRNAs in T-cell malignancies and their metabolic roles

T-cell malignancy is a broad term used for a diverse group of disease subtypes representing dysfunctional malignant T cells transformed at various stages of their clonal evolution. Despite having similar clinical manifestations, these disease groups have different disease progressions and diagnostic parameters. The effective diagnosis and prognosis of such a diverse disease group demands testing of molecular entities that capture footprints of the disease physiology in its entirety. MicroRNAs (miRNAs) are a group of noncoding RNA molecules that regulate the expression of genes and, while doing so, leave behind specific miRNA signatures corresponding to cellular expression status in an altered stage of a disease. Using miRNAs as a diagnostic tool is justified, as they can effectively distinguish expressional diversity between various tumors and within subtypes of T-cell malignancies. As global attention for cancer diagnosis shifts toward liquid biopsy, diagnosis using miRNAs is more relevant in blood cancers than in solid tumors. We also lay forward the diagnostic significance of miRNAs that are indicative of subtype, progression, severity, therapy response, and relapse. This review discusses the potential use and the role of miRNAs, miRNA signatures, or classifiers in the diagnosis of major groups of T-cell malignancies like T-cell acute lymphoblastic lymphoma (T-ALL), peripheral T-cell lymphoma (PTCL), extranodal NK/T-cell lymphoma (ENKTCL), and cutaneous T-cell lymphoma (CTCL). The review also briefly discusses major diagnostic miRNAs having prominent metabolic roles in these malignancies to highlight their importance among other dysregulated miRNAs.

Blockade of the Immune Checkpoint CD47 by TTI-621 Potentiates the Response to Anti-PD-L1 in Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma (CTCL) is an incurable and cosmetically disfiguring disease associated with microenvironmental signals. We investigated the effects of CD47 and PD-L1 immune checkpoint blockades, as a strategy for targeting both innate and adaptive immunity. CIBERSORT analysis identified the immune-cell composition in the CTCL tumor microenvironment and the immune checkpoint expression profile for each immune-cell gene cluster from CTCL lesions. We investigated the relationship between MYC and CD47 and PD-L1 expression and found that MYC short hairpin RNA knockdown and MYC functional suppression by TTI-621 (SIRPαFc) and anti-PD-L1 (durvalumab) in CTCL cell lines reduced the expression of CD47 and PDL1 mRNA and protein as measured by qPCR and flow cytometry, respectively. In vitro, blockade of the CD47-SIRPα interaction with TTI-621 increased the phagocytic activity of macrophages against CTCL cells and enhanced CD8+ T-cell-mediated killing in a mixed leucocyte reaction. Moreover, TTI-621 synergized with anti-PD-L1 in macrophages reprogram to M1-like phenotypes and inhibited CTCL cell growth. These effects were mediated by cell death-related pathways, including apoptosis, autophagy, and necroptosis. Collectively, our findings show that CD47 and PD-L1 are critical regulators of immune surveillance in CTCL and that dual targeting of CD47 and PD-L1 will provide insight into tumor immunotherapy for CTCL.

Role of Neutrophil-to-Lymphocyte Ratio (NLR) in Patients with Mycosis Fungoides

BACKGROUND

The neutrophil/lymphocyte ratio (NLR) at baseline has been demonstrated to correlate with higher stages of disease and to be a prognostic factor in numerous cancers. However, its function as a prognostic factor for mycosis fungoides (MF) has not been yet clarified.

OBJECTIVE

Our work aimed to assess the association of the NLR with different stages of MF and to outline whether higher values of this marker are related to a more aggressive MF.

METHODS

We retrospectively calculated the NLRs in 302 MF patients at the moment of diagnosis. The NLR was obtained using the complete blood count values.

RESULTS

The median NLR among patients with early stage disease (low-grade IA-IB-IIA) was 1.88, while the median NLR for patients with high-grade MF (IIB-IIIA-IIIB) was 2.64. Statistical analysis showed positive associations of advanced MF stages with NLRs higher than 2.3.

CONCLUSIONS

Our analysis demonstrates that the NLR represents a cheap and easily available parameter functioning as a marker for advanced MF. This might guide physicians in recognizing patients with advanced stages of disease requiring a strict follow-up or an early treatment.

Dysregulation of Plasma miR-146a and miR-155 Expression Profile in Mycosis Fungoides Is Associated with rs2910164 and rs767649 Polymorphisms

Diagnosis of Mycosis Fungoides (MF) may be challenging, due to its polymorphic nature. The use of miRNAs as biomarkers to assist in diagnosis has been investigated, mainly in skin lesion biopsies. The purpose of this study is to evaluate the plasma levels of miR-146a and miR-155 in MF patients and to investigate their association with SNPs of their genes. Plasma miRNAs were quantified by RT-qPCR. Genomic DNA was used for SNPs’ genotyping by Sanger sequencing. Plasma levels of miR-146a and miR-155 were significantly higher in patients vs. controls, in early MF patients vs. controls, and in advanced vs. early MF patients. Both miRNAs’ levels were significantly higher in stage IIB vs. early-stage patients. miR-155 plasma levels were significantly higher in patients with skin tumors or erythroderma. CC genotype (rs2910164 C>G) was significantly more frequent in healthy controls and associated with lower MF risk and lower miR-146a levels. The AA genotype (rs767649 T>A) was significantly more frequent in patients and correlated with increased MF risk and increased miR-155 levels. The combination of GG+AA was only detected in patients and was correlated with higher MF susceptibility. Increased mir-146a and mir-155 plasma levels in MF is an important finding to establish putative noninvasive biomarkers. The presence of SNPs is closely associated with miRs’ expression, and possibly with disease susceptibility.

Over-Expression of GUSB Leads to Primary Resistance of Anti-PD1 Therapy in Hepatocellular Carcinoma

Immunotherapy treatments, particularly immune checkpoint blockade, can result in benefits in clinical settings. But many pre-clinical and clinical studies have shown that resistance to anti-PD1 therapy frequently occurs, leading to tumor recurrence and treatment failure, including in patients with hepatocellular carcinoma (HCC). In this study, 10 patients with HCC were remedied with anti-PD1, and pre-treatment biopsy samples were sequenced for 289 nanostring panel RNA to compare responsive and non-responsive tumors to identify possible pretreatment biomarkers or targets of anti-PD1 therapeutic responses. Fortunately, the expression of β-Glucuronidase (GUSB) in the non-responding tumors was found to be remarkably higher than that in responding tumors. Results of the cell counting kit 8 (CCK8), 5-ethynyl-2’-deoxyuridine (EdU), transwell, wound healing test, and flow cytometry showed that GUSB facilitated proliferation, invasion, as well as migration of human HCC cells and downregulated PD-L1 expression by promoting miR-513a-5p. Additionally, as a GUSB inhibitor, amoxapine can reduce the progression of human HCC cells, and was an effective treatment for HCC and improved the sensitivity of anti-PD1 therapy. In summary, this study reveals that increased GUSB downregulates PD-L1 expression by promoting miR-513a-5p, leading to primary resistance to anti-PD1 treatment in HCC, and amoxapine enhances the sensitivity of anti-PD1 therapy by inhibiting GUSB, providing a new strategy and method for improving the efficacy of anti-PD1 therapy and bringing new prospects for therapy of HCC.