High Expression of PDLIM2 Predicts a Poor Prognosis in Prostate Cancer and Is Correlated with Epithelial-Mesenchymal Transition and Immune Cell Infiltration

Tumor promoting effect of PDLIM2 downregulation involves mitochondrial ROS, oncometabolite accumulations and HIF-1α activation

BACKGROUND

Cancer is characterized by dysregulated cellular metabolism. Thus, understanding the mechanisms underlying these metabolic alterations is important for developing targeted therapies. In this study, we investigated the pro-tumoral effect of PDZ and LIM domain 2 (PDLIM2) downregulation in lung cancer growth and its association with the accumulation of mitochondrial ROS, oncometabolites and the activation of hypoxia-inducible factor-1 (HIF-1) α in the process.

METHODS

Databases and human cancer tissue samples were analyzed to investigate the roles of PDLIM2 and HIF-1α in cancer growth. DNA microarray and gene ontology enrichment analyses were performed to determine the cellular functions of PDLIM2. Seahorse assay, flow cytometric analysis, and confocal microscopic analysis were employed to study mitochondrial functions. Oncometabolites were analyzed using liquid chromatography-mass spectrometry (LC-MS). A Lewis lung carcinoma (LLC) mouse model was established to assess the in vivo function of PDLIM2 and HIF-1α.

RESULTS

The expression of PDLIM2 was downregulated in lung cancer, and this downregulation correlated with poor prognosis in patients. PDLIM2 highly regulated genes associated with mitochondrial functions. Mechanistically, PDLIM2 downregulation resulted in NF-κB activation, impaired expression of tricarboxylic acid (TCA) cycle genes particularly the succinate dehydrogenase (SDH) genes, and mitochondrial dysfunction. This disturbance contributed to the accumulation of succinate and other oncometabolites, as well as the buildup of mitochondrial reactive oxygen species (mtROS), leading to the activation of hypoxia-inducible factor 1α (HIF-1α). Furthermore, the expression of HIF-1α was increased in all stages of lung cancer. The expression of PDLIM2 and HIF-1α was reversely correlated in lung cancer patients. In the animal study, the orally administered HIF-1α inhibitor, PX-478, significantly reduces PDLIM2 knockdown-promoted tumor growth.

CONCLUSION

These findings shed light on the complex action of PDLIM2 on mitochondria and HIF-1α activities in lung cancer, emphasizing the role of HIF-1α in the tumor-promoting effect of PDLIM2 downregulation. Additionally, they provide new insights into a strategy for precise targeted treatment by suggesting that HIF-1α inhibitors may serve as therapy for lung cancer patients with PDLIM2 downregulation.

PDLIM1 interacts with HK2 to promote gastric cancer progression through enhancing the Warburg effect via Wnt/β-catenin signaling

PDZ and LIM domain protein 1 (PDLIM1) is a cytoskeletal protein and is associated with the malignant pathological features of several tumors. However, the prognostic value of PDLIM1 and the molecular mechanisms by which it is involved in the metabolism and progression in gastric cancer (GC) are still unclear. The GEPIA database was used to predict the expression and prognosis of PDLIM1 in GC. qRT-PCR and western blot assays were applied to detect the mRNA and protein expression in GC tissues and cells. Loss- and gain-of-function experiments were performed to evaluate the biological role of PDLIM1 in GC cells. The Warburg effect was detected by a battery of glycolytic indicators. The interaction of PDLIM1 and hexokinase 2 (HK2) was determined by a co-immunoprecipitation assay. Furthermore, the modulatory effects of PDLIM1 and HK2 on Wnt/β-catenin signaling were assessed. The results showed that PDLIM1 expression was upregulated in GC tissues and cells and was associated with a poor prognosis for GC patients. PDLIM1 inhibition reduced GC cell proliferation, migration and invasion and promoted cell apoptosis. In the glucose deprivation (GLU-D) condition, the PDLIM1 level was reduced and PDLIM1 overexpression led to an increase in glycolysis. Besides, mechanistic investigation showed that PDLIM1 interacted with HK2 to mediate biological behaviors and the glycolysis of GC through Wnt/β-catenin signaling under glucose deprivation. In conclusion, PDLIM1 interacts with HK2 to promote gastric cancer progression by enhancing the Warburg effect via Wnt/β-catenin signaling.

The Potential of Extracellular Matrix- and Integrin Adhesion Complex-Related Molecules for Prostate Cancer Biomarker Discovery

Prostate cancer is among the top five cancer types according to incidence and mortality. One of the main obstacles in prostate cancer management is the inability to foresee its course, which ranges from slow growth throughout years that requires minimum or no intervention to highly aggressive disease that spreads quickly and resists treatment. Therefore, it is not surprising that numerous studies have attempted to find biomarkers of prostate cancer occurrence, risk stratification, therapy response, and patient outcome. However, only a few prostate cancer biomarkers are used in clinics, which shows how difficult it is to find a novel biomarker. Cell adhesion to the extracellular matrix (ECM) through integrins is among the essential processes that govern its fate. Upon activation and ligation, integrins form multi-protein intracellular structures called integrin adhesion complexes (IACs). In this review article, the focus is put on the biomarker potential of the ECM- and IAC-related molecules stemming from both body fluids and prostate cancer tissue. The processes that they are involved in, such as tumor stiffening, bone turnover, and communication via exosomes, and their biomarker potential are also reviewed.

PDZ and LIM Domain-Encoding Genes: Their Role in Cancer Development

PDZ-LIM family proteins (PDLIMs) are a kind of scaffolding proteins that contain PDZ and LIM interaction domains. As protein-protein interacting molecules, PDZ and LIM domains function as scaffolds to bind to a variety of proteins. The PDLIMs are composed of evolutionarily conserved proteins found throughout different species. They can participate in cell signal transduction by mediating the interaction of signal molecules. They are involved in many important physiological processes, such as cell differentiation, proliferation, migration, and the maintenance of cellular structural integrity. Studies have shown that dysregulation of the PDLIMs leads to tumor formation and development. In this paper, we review and integrate the current knowledge on PDLIMs. The structure and function of the PDZ and LIM structural domains and the role of the PDLIMs in tumor development are described.

New insight in urological cancer therapy: From epithelial-mesenchymal transition (EMT) to application of nano-biomaterials

A high number of cancer-related deaths (up to 90) are due to metastasis and simple definition of metastasis is new colony formation of tumor cells in a secondary site. In tumor cells, epithelial-mesenchymal transition (EMT) stimulates metastasis and invasion, and it is a common characteristic of malignant tumors. Prostate cancer, bladder cancer and renal cancer are three main types of urological tumors that their malignant and aggressive behaviors are due to abnormal proliferation and metastasis. EMT has been well-documented as a mechanism for promoting invasion of tumor cells and in the current review, a special attention is directed towards understanding role of EMT in malignancy, metastasis and therapy response of urological cancers. The invasion and metastatic characteristics of urological tumors enhance due to EMT induction and this is essential for ensuring survival and ability in developing new colonies in neighboring and distant tissues and organs. When EMT induction occurs, malignant behavior of tumor cells enhances and their tend in developing therapy resistance especially chemoresistance promotes that is one of the underlying reasons for therapy failure and patient death. The lncRNAs, microRNAs, eIF5A2, Notch-4 and hypoxia are among common modulators of EMT mechanism in urological tumors. Moreover, anti-tumor compounds such as metformin can be utilized in suppressing malignancy of urological tumors. Besides, genes and epigenetic factors modulating EMT mechanism can be therapeutically targeted for interfering malignancy of urological tumors. Nanomaterials are new emerging agents in urological cancer therapy that they can improve potential of current therapeutics by their targeted delivery to tumor site. The important hallmarks of urological cancers including growth, invasion and angiogenesis can be suppressed by cargo-loaded nanomaterials. Moreover, nanomaterials can improve chemotherapy potential in urological cancer elimination and by providing phototherapy, they mediate synergistic tumor suppression. The clinical application depends on development of biocompatible nanomaterials.

Correlation between hyperbilirubinemia risk and immune cell mitochondria parameters in neonates with jaundice

Purpose

To explore the correlation between mitochondria parameters of immune cells and hyperbilirubinemia risk in hospitalized neonates with jaundice.

Methods

This retrospective study included jaundiced neonates born between September 2020 and March 2022 at Shaoxing Keqiao Women & Children's Hospital. The neonates were divided into low, intermediate-low, intermediate-high, and high-risk groups according to the hyperbilirubinemia risk. The purpose parameters including percentage, absolute count, mitochondrial mass (MM), and single-cell MM (SCMM) of peripheral blood T lymphocytes detected by flow cytometry were collected.

Results

Finally, 162 neonates with jaundice (47, 41, 39, and 35 with low, intermediate-low, intermediate-high, and high-risk) were included. CD3⁺ SCMM was significantly higher in the high-risk group compared with the low and intermediate-low-risk groups (both P < 0.0083), CD4⁺ SCMM was significantly higher in the high-risk group compared with the three other groups (all P < 0.0083), and CD8⁺ SCMM was significantly higher in the intermediate-low and high-risk groups compared with the low-risk group (both P < 0.0083). CD3⁺ (r = 0.34, P < 0.001) and CD4⁺ (r = 0.20, P = 0.010) SCMM positively correlated with bilirubin levels.

Conclusions

The mitochondrial SCMM parameters differed significantly among jaundiced neonates with different hyperbilirubinemia risks. CD3⁺ and CD4⁺ T cell SCMM values were positively correlated with the serum bilirubin levels, and might correlated with hyperbilirubinemia risk.

Comprehensive Analyses and Immunophenotyping of LIM Domain Family Genes in Patients with Non-Small-Cell Lung Cancer

The LIM domain family genes play a crucial role in various tumors, including non-small-cell lung cancer (NSCLC). Immunotherapy is one of the most significant treatments for NSCLC, and its effectiveness largely depends on the tumor microenvironment (TME). Currently, the potential roles of LIM domain family genes in the TME of NSCLC remain elusive. We comprehensively evaluated the expression and mutation patterns of 47 LIM domain family genes in 1089 NSCLC samples. Using unsupervised clustering analysis, we classified patients with NSCLC into two distinct gene clusters, i.e., the LIM-high group and the LIM-low group. We further investigated the prognosis, TME cell infiltration characteristics, and immunotherapy in the two groups. The LIM-high and LIM-low groups had different biological processes and prognoses. Moreover, there were significant differences in TME characteristics between the LIM-high and LIM-low groups. Specifically, enhanced survival, immune cell activation, and high tumor purity were demonstrated in patients of the LIM-low group, implying an immune-inflamed phenotype. Moreover, the LIM-low group had higher immune cell proportion scores than the LIM-high group and was more responsive to immunotherapy than the LIM-low group. Additionally, we screened out LIM and senescent cell antigen-like domain 1 (LIMS1) as a hub gene of the LIM domain family via five different algorithms of plug-in cytoHubba and the weighted gene co-expression network analysis. Subsequently, proliferation, migration, and invasion assays demonstrated that LIMS1 acts as a pro-tumor gene that promotes the invasion and progression of NSCLC cell lines. This is the first study to reveal a novel LIM domain family gene-related molecular pattern associated with the TME phenotype, which would increase our understanding of the heterogeneity and plasticity of the TME in NSCLC. LIMS1 may serve as a potential therapeutic target for NSCLC.

PDLIM2 is highly expressed in Breast Cancer tumour-associated macrophages and is required for M2 macrophage polarization

The PDZ-LIM domain-containing protein 2 (PDLIM2) regulates cell polarity and the protein stability of key transcription factors in epithelial and hemopoietic cells. We previously reported that PDLIM2 is more highly expressed in Triple Negative Breast Cancer (TNBC) than in other breast cancer types or normal breast tissue. In the course of the TNBC study, it was noted that PDLIM2 was highly expressed in the stroma of PDLIM2-expressing tumours. Here, we investigated the phenotype of these stromal cells and whether any infiltrating immune population was linked to PDLIM2 expression. We found that high PDLIM2 expression in breast tumours was associated with higher levels of infiltrating M2 macrophages, but was not associated with infiltrating T cell sub-populations. We then tested whether PDLIM2 contributes to macrophage differentiation or function by using cultures of bone marrow-derived macrophages from wildtype and Pdlim2 knockout mice. This demonstrated that PDLIM2 is required for naïve macrophage migration and for the full adoption of IL-4-induced M2 polarization, including expression of M2 phenotypic markers, cell adhesion and cell migration. TLR4-, TLR3- or IFNγ-induced M1 macrophage activity was less dependent on PDLIM2. Finally, analysis of publicly available breast cancer datasets showed that high PDLIM2 expression is associated with increased M2 macrophage infiltration. We conclude that PDLIM2 expression influences the tumour associated stroma and, in particular, M2 macrophage infiltration that may contribute to the progression of TNBC or other subsets of breast cancer.