Probes for LONG

Long bones are formed and repaired through the process of endochondral ossification. Activation of G protein-coupled receptor (GPCR) signaling pathways is crucial for skeletal development and long bone growth. G protein-gated inwardly-rectifying K+ (GIRK) channel genes are key functional components and effectors of GPCR signaling pathways in excitable cells of the heart and brain, but their roles in non-excitable cells that directly contribute to endochondral bone formation have not been studied. In this study, we analyzed skeletal phenotypes of Girk2-/-, Girk3-/- and Girk2/3-/- mice. Bones from 12-week-old Girk2-/- mice were normal in length, but femurs and tibiae from Girk3-/- and Girk2/3-/- mice were longer than age-matched controls at 12-weeks-old. Epiphyseal chondrocytes from 5-day-old Girk3-/- mice expressed higher levels of genes involved in collagen chain trimerization and collagen fibril assembly, lower levels of genes encoding VEGF receptors, and produced larger micromasses than wildtype chondrocytes in vitro. Girk3-/- chondrocytes were also more responsive to the kappa opioid receptor (KOR) ligand dynorphin, as evidenced by greater pCREB expression, greater cAMP and GAG production, and upregulation of Col2a1 and Sox9 transcripts. Imaging studies showed that Kdr (Vegfr2) and endomucin expression was dramatically reduced in bones from young Girk3-/- mice, supporting a role for delayed vasculogenesis and extended postnatal endochondral bone growth. Together these data indicate that GIRK3 controls several processes involved in bone lengthening.

To determine the expression of long non-coding RNA urothelial cancer-associated 1 (UCA1) by performing array-based quantitative polymerase chain reaction (PCR) and to identify the clinicopathological significance of UCA1 expression in prostate cancer using in situ hybridization (ISH) of surgically resected specimens.Array-based quantitative PCR was performed using 10 pairs of fresh malignant (prostate cancer) and normal tissue samples to determine UCA1 expression. Single-color RNA ISH of surgically resected prostate cancer specimens was performed using 70 formalin-fixed, paraffin-embedded tissue specimens to examine the clinicopathological significance of UCA1.Prostate cancer tissues exhibited higher levels of UCA1 expression than paired benign tissues. Furthermore, a correlation between high UCA1 expression and unfavourable clinicopathological characteristics, including advanced pathologic T stage, extraprostatic extension, presence of Gleason pattern 5, and involvement of the resection margins was observed. Notably, increased UCA1 expression significantly correlated with high- or very-high-risk patients, as defined by the 2023 National Comprehensive Cancer Network guidelines.UCA1 could be used as a novel diagnostic and prognostic biomarker for establishing an effective treatment protocol for prostate cancer.

Genetic mutations in the Xylt1 gene are associated with Desbuquois dysplasia type II syndrome characterized by sever prenatal and postnatal short stature. However, the specific role of XylT-I in the growth plate is not completely understood. Here, we show that XylT-I is expressed and critical for the synthesis of proteoglycans in resting and proliferative but not in hypertrophic chondrocytes in the growth plate. We found that loss of XylT-I induces hypertrophic phenotype-like of chondrocytes associated with reduced interterritorial matrix. Mechanistically, deletion of XylT-I impairs the synthesis of long glycosaminoglycan chains leading to the formation of proteoglycans with shorter glycosaminoglycan chains. Histological and Second Harmonic Generation microscopy analysis revealed that deletion of XylT-I accelerated chondrocyte maturation and prevents chondrocytes columnar organization and arrangement in parallel of collagen fibers in the growth plate, suggesting that XylT-I controls chondrocyte maturation and matrix organization. Intriguingly, loss of XylT-I induced at embryonic stage E18.5 the migration of progenitor cells from the perichondrium next to the groove of Ranvier into the central part of epiphysis of E18.5 embryos. These cells characterized by higher expression of glycosaminoglycans exhibit circular organization then undergo hypertrophy and death creating a circular structure at the secondary ossification center location. Our study revealed an uncovered role of XylT-I in the synthesis of proteoglycans and provides evidence that the structure of glycosaminoglycan chains of proteoglycans controls chondrocyte maturation and matrix organization.

In addition to serving as a prosthetic group for enzymes and a hemoglobin structural component, heme is a crucial homeostatic regulator of erythroid cell development and function. While lncRNAs modulate diverse physiological and pathological cellular processes, their involvement in heme-dependent mechanisms is largely unexplored. In this study, we elucidated a lncRNA (UCA1)-mediated mechanism that regulates heme metabolism in human erythroid cells. We discovered that UCA1 expression is dynamically regulated during human erythroid maturation, with a maximal expression in proerythroblasts. UCA1 depletion predominantly impairs heme biosynthesis and arrests erythroid differentiation at the proerythroblast stage. Mechanistic analysis revealed that UCA1 physically interacts with the RNA-binding protein PTBP1, and UCA1 functions as an RNA scaffold to recruit PTBP1 to ALAS2 mRNA, which stabilizes ALAS2 mRNA. These results define a lncRNA-mediated posttranscriptional mechanism that provides a new dimension into how the fundamental heme biosynthetic process is regulated as a determinant of erythrocyte development.

Non‑coding RNAs (ncRNAs) have been shown to serve important roles in carcinogenesis via complex mechanisms, including transcriptional and post‑transcriptional regulation, and chromatin interactions. Urothelial carcinoma‑associated 1 (UCA1), a long ncRNA, was recently shown to have tumorigenic properties in urothelial bladder cancer (UBC), as demonstrated by enhanced proliferation, migration, invasion and therapy resistance of UBC cell lines in vitro. These in vitro findings suggested that UCA1 is associated with aggressive tumor behavior and could have prognostic implications in UBC. The aims of the present study were to therefore to investigate the statistical associations between UCA1 RNA expression and UBC pathological features, patient prognosis and p53 and Ki‑67 expression. Chromogenic in situ hybridization and immunohistochemistry were performed on UBC tissue microarrays to characterize UCA1 RNA, and p53 and Ki‑67 expression in 208 UBC cases, including 145 non‑muscle‑invasive and 63 muscle‑invasive cases. UCA1 was observed in the tumor cells of 166/208 (80%) UBC cases tested. No expression was noted in normal stromal and endothelium cells. Patients with UBC that overexpressed UCA1 (35%) had a significantly higher survival rate (P=0.006) compared with that in patients with UBC that did not overexpress UCA1. This prognostic factor was independent of tumor morphology, concomitant carcinoma in situ, tumor grade and tumor stage. In addition, the absence of UCA1 overexpression was significantly associated with a high Ki‑67 proliferative index (P=0.008) and a p53 'mutated' immunoprofile (strong nuclear expression or complete absence of staining; P=0.003). In conclusion, the present results identified UCA1 as potentially being a novel independent prognostic marker in UBC that was associated with a better patient prognosis and that could serve a pivotal role in bladder cancer carcinogenesis.