Pyrophosphatase 1 expression is associated with future recurrence and overall survival in Chinese patients with intrahepatic cholangiocarcinoma

Current and future perspectives on the regulation and functions of miR-545 in cancer development

Micro ribonucleic acids (miRNAs) are a highly conserved class of single-stranded non-coding RNAs. Within the miR-545/374a cluster, miR-545 resides in the intron of the long non-coding RNA (lncRNA) FTX on Xq13.2. The precursor form, pre-miR-545, is cleaved to generate two mature miRNAs, miR-545-3p and miR-545-5p. Remarkably, these two miRNAs exhibit distinct aberrant expression patterns in different cancers; however, their expression in colorectal cancer remains controversial. Notably, miR-545-3p is affected by 15 circular RNAs (circRNAs) and 10 long non-coding RNAs (lncRNAs), and it targets 27 protein-coding genes (PCGs) that participate in the regulation of four signaling pathways. In contrast, miR-545-5p is regulated by one circRNA and five lncRNAs, it targets six PCGs and contributes to the regulation of one signaling pathway. Both miR-545-3p and miR-545-5p affect crucial cellular behaviors, including cell cycle, proliferation, apoptosis, epithelial-mesenchymal transition, invasion, and migration. Although low miR-545-3p expression is associated with poor prognosis in three cancer types, studies on miR-545-5p are yet to be reported. miR-545-3p operates within a diverse range of regulatory networks, thereby augmenting the efficacy of cancer chemotherapy, radiotherapy, and immunotherapy. Conversely, miR-545-5p enhances immunotherapy efficacy by inhibiting T-cell immunoglobulin and mucin-domain containing-3 (TIM-3) expression. In summary, miR-545 holds immense potential as a cancer biomarker and therapeutic target. The aberrant expression and regulatory mechanisms of miR-545 in cancer warrant further investigation.

PPA1, an energy metabolism initiator, plays an important role in the progression of malignant tumors

Inorganic pyrophosphatase (PPA1) encoded by PPA1 gene belongs to Soluble Pyrophosphatases (PPase) family and is expressed widely in various tissues of Homo sapiens, as well as significantly in a variety of malignancies. The hydrolysis of inorganic pyrophosphate (PPi) to produce orthophosphate (Pi) not only dissipates the negative effects of PPi accumulation, but the energy released by this process also serves as a substitute for ATP. PPA1 is highly expressed in a variety of tumors and is involved in proliferation, invasion, and metastasis during tumor development, through the JNK/p53, Wnt/β-catenin, and PI3K/AKT/GSK-3β signaling pathways. Because of its remarkable role in tumor development, PPA1 may serve as a biological target for adjuvant therapy of tumor malignancies. Further, PPA1 is a potential biomarker to predict survival in patients with cancer, where the assessment of its transcriptional regulation can provide an in-depth understanding. Herein, we describe the signaling pathways through which PPA1 regulates malignant tumor progression and provide new insights to establish PPA1 as a biomarker for tumor diagnosis.

Ribosomal protein L34 is a potential prognostic biomarker and therapeutic target in hilar cholangiocarcinoma

Background

Ribosomal protein 34 (RPL34) is a highly conserved protein belonging to the 60S large subunit of mammalian ribosomes that has been found to be dysregulated in a variety of human tumors. However, there are limited results that illuminate the role and expression profiles of RPL34 in hilar cholangiocarcinoma (HCCA).

Methods

RPL34 expression was detected in human HCCA by immunohistochemistry. The relationship of RPL34 expression with clinical outcomes was evaluated by univariate and multivariate analyses. The effect of RPL34 on cell migration and tumor growth was detected after silencing endogenous RPL34 expression.

Results

RPL34 was overexpressed in HCCA compared with normal tissue samples and correlated significantly with regional lymph node metastasis and poorly/undifferentiated tumors. Patients with high RPL34 expression had a shorter time to recur and a poorer outcome than those without RPL34 expression. Silencing RPL34 inhibited cell proliferation and migration in vitro and upregulated E-cadherin. Silencing RPL34 also attenuated tumor growth in vivo.

Conclusions

Our findings suggested that RPL34 might serve as a promising prognostic biomarker and a potential therapeutic target for the treatment of HCCA.

Synthesis of Inorganic Pyrophosphatase-Nanodiamond Conjugates Resistant to Calcium and Fluoride

Pyrophosphate arthropathy is the mineralization defect in humans caused by the deposition of microcrystals of calcium pyrophosphate dihydrate in joint tissues. As a potential therapeutic strategy for the treatment of pyrophosphate arthropathy, delivery of exogenous pyrophosphate-hydrolyzing enzymes, inorganic pyrophosphatases (PPases), to the synovial fluid has been suggested. Previously, we synthesized the conjugates of Escherichia coli PPase (Ec-PPase) with detonation synthesis nanodiamonds (NDs) as a delivery platform, obtaining the hybrid biomaterial retaining high pyrophosphate-hydrolyzing activity in vitro. However, most known PPases including Ec-PPase in the soluble form are strongly inhibited by Ca²⁺ ions. Because synovial fluid contains up to millimolar concentrations of soluble calcium, this inhibition might limit the in vivo application of Ec-PPase-based material in joint tissues. In this work, we proposed other bacterial PPases from Mycobacterium tuberculosis (Mt-PPase), which are resistant to the inhibition by Ca²⁺ ions, as an active PP_i-hydrolyzing agent. We synthesized conjugates of Mt-PPase with NDs and tested their activity under various conditions. Unexpectedly, conjugates of both Ec-PPase and Mt-PPase with aminated NDs retained significant hydrolytic activity in the presence of well-known mechanism-based PPase inhibitors, fluoride or calcium. The incomplete inhibition of PPases by fluoride or calcium was found for the first time.