Deubiquitinating enzymes: potential regulators of the tumor microenvironment and implications for immune evasion.

Ubiquitination and deubiquitination are important forms of posttranslational modification that govern protein homeostasis. Deubiquitinating enzymes (DUBs), a protein superfamily consisting of more than 100 members, deconjugate ubiquitin chains from client proteins to regulate cellular homeostasis. However, the dysregulation of DUBs is reportedly associated with several diseases, including cancer. The tumor microenvironment (TME) is a highly complex entity comprising diverse noncancerous cells (e.g., immune cells and stromal cells) and the extracellular matrix (ECM). Since TME heterogeneity is closely related to tumorigenesis and immune evasion, targeting TME components has recently been considered an attractive therapeutic strategy for restoring antitumor immunity. Emerging studies have revealed the involvement of DUBs in immune modulation within the TME, including the regulation of immune checkpoints and immunocyte infiltration and function, which renders DUBs promising for potent cancer immunotherapy. Nevertheless, the roles of DUBs in the crosstalk between tumors and their surrounding components have not been comprehensively reviewed. In this review, we discuss the involvement of DUBs in the dynamic interplay between tumors, immune cells, and stromal cells and illustrate how dysregulated DUBs facilitate immune evasion and promote tumor progression. We also summarize potential small molecules that target DUBs to alleviate immunosuppression and suppress tumorigenesis. Finally, we discuss the prospects and challenges regarding the targeting of DUBs in cancer immunotherapeutics and several urgent problems that warrant further investigation.

XPF-ERCC1 Blocker Improves the Therapeutic Efficacy of 5-FU- and Oxaliplatin-Based Chemoradiotherapy in Colorectal Cancer.

5-FU-based chemoradiotherapy (CRT) and oxaliplatin-based CRT are commonly used therapies for advanced colorectal cancer (CRC). However, patients with a high expression of ERCC1 have a worse prognosis than those with a low expression. In this study, we investigated the effect of XPF-ERCC1 blockers on chemotherapy and 5-FU-based CRT and oxaliplatin (OXA)-based CRT in colorectal cancer cell lines. We investigated the half-maximal inhibitory concentration (IC50) of 5-FU, OXA, XPF-ERCC1 blocker, and XPF-ERCC1 blocker, and 5-FU or OXA combined and analyzed the effect of XPF-ERCC1 blocker on 5-FU-based CRT and oxaliplatin-based CRT. Furthermore, the expression of XPF and γ-H2AX in colorectal cells was analyzed. In animal models, we combined the XPF-ERCC1 blocker with 5-FU and OXA to investigate the effects of RC and finally combined the XPF-ERCC1 blocker with 5-FU- and oxaliplatin-based CRT. In the IC50 analysis of each compound, the cytotoxicity of the XPF-ERCC1 blocker was lower than that of 5-FU and OXA. In addition, the XPF-ERCC1 blocker combined with 5-FU or OXA enhanced the cytotoxicity of the chemotherapy drugs in colorectal cells. Furthermore, the XPF-ERCC1 blocker also increased the cytotoxicity of 5-FU-based CRT and OXA -based CRT by inhibiting the XPF product DNA locus. In vivo, the XPF-ERCC1 blocker was confirmed to enhance the therapeutic efficacy of 5-FU, OXA, 5-FU-based CRT, and OXA CRT. These findings show that XPF-ERCC1 blockers not only increase the toxicity of chemotherapy drugs but also increase the efficacy of combined chemoradiotherapy. In the future, the XPF-ERCC1 blocker may be used to improve the efficacy of 5-FU- and oxaliplatin-based CRT.

Diphenyl disulfide potentiates the apoptosis of breast cancer cells through Bax proteolytic activation with accompanying autophagy.

Breast cancer is a leading cause of cancer-related death worldwide, and chemoresistance often leads to poor patient outcomes. In this study, we investigated the anticancer activity of synthetic diphenyl disulfide (DPDS) in breast cancer cell lines. DPDS inhibited cellular proliferation and viability in a dose-dependent manner and reduced colony formation, an index of clonogenicity. Annexin-V and 7-AAD double staining showed that DPDS could induce the apoptosis of breast cancer cells. Western blotting of the expression of Bax p21 and its cleaved form p18 suggested the activation of p18 Bax-induced apoptosis. Furthermore, the increased expression of the autophagy marker LC3B-II indicated autophagic lysosome accumulation induced by DPDS. Our findings suggest that DPDS has potential as a candidate for treating breast cancer, and further modifications and optimizations are warranted.

The Pyroptotic and Nonpyroptotic Roles of Gasdermins in Modulating Cancer Progression and Their Perspectives on Cancer Therapeutics.

Gasdermins (GSDMs) are a protein family encoded by six paralogous genes in humans, including GSDMA, GSDMB, GSDMC, GSDMD, GSDME (also known as DFNA5), and DFNB59 (also known as pejvakin). Structurally, members of the GSDM family possess a C-terminus (an autoinhibitory domain) and a positively charged N-terminus (a pore-forming domain) linked with divergent peptide linkers. Recently, GSDMs have been identified as key executors of pyroptosis (an immunogenic programmed cell death) due to their pore-forming activities on the plasma membrane when proteolytically cleaved by caspases or serine proteases. Accumulating studies suggest that chemoresistance is attributed to dysregulation of apoptotic machinery and that inducing pyroptosis to bypass aberrant apoptosis can potently resensitize apoptosis-resistant cancer to chemotherapeutics. Pyroptosis is initiated by pore formation and culminates with plasma membrane rupture; these processes enable the release of proinflammatory cytokines (e.g., IL-1ß and IL-18) and damage-associated molecular patterns, which further modulate antitumor immunity within the tumor microenvironment. Although pyroptosis is considered a promising strategy to boost antitumor effects, it is also reported to cause unwanted tissue damage (e.g., gut damage and nephrotoxicity). Intriguingly, mounting evidence has uncovered nonpyroptotic roles of GSDMs in tumorigenesis, such as proliferation, invasion, metastasis, and drug resistance. Thus, this provides a rationale for GSDMs as potential therapeutic targets. Taken together, we shed unbiased light on the pyroptosis-dependent roles of GSDMs in cancer progression and highlighted how GSDMs modulate tumorigenesis in a pyroptosis-independent manner. It is evident that targeting GSDMs seems profound in cancer management; however, several problems require further investigation to target GSDMs from bench to bedside, which is elucidated in the discussion section.

ATG4B and pS383/392-ATG4B serve as potential biomarkers and therapeutic targets of colorectal cancer.

BACKGROUND: Autophagy related protease 4B (ATG4B) is a protease required for autophagy processing, which is strongly implicated in cancer progression.  Phosphorylation of ATG4B is crucial for activation of its protease activity.  However, little is known about the relationship of ATG4B and its phosphorylated form at Ser 383 and 392 sites (pS383/392-ATG4B), with clinical outcomes, particularly in colorectal cancer (CRC). METHODS: The ATG4B gene expression in CRC patients was obtained from The Cancer Genome Atlas (TCGA) database to analyze its clinical relevance. Tissue microarrays composed of 118 CRC patient specimens were used to determine the associations of ATG4B and pS383/392-ATG4B protein levels with prognosis. The biological functions of ATG4B in CRC cells were inspected with cell proliferation, mobility and spheroid culture assays. RESULTS: ATG4B gene expression was elevated in tumor tissues of CRC patients compared to that in adjacent normal tissues and high level of ATG4B expression was associated with poor survival. Similarly, protein levels of ATG4B and pS383/392-ATG4B were highly correlated with worse overall survival and disease-free survival. Stratification analysis results showed that high level of ATG4B had significantly higher risk of mortality in males and elderly patients compared to those female patients and patients 60 years or younger. In contrast, multivariate Cox's regression analysis indicated that high level of pS383/392-ATG4B was significantly linked to unfavorable overall survival and disease-free survival of males and elderly patients, whereas, it had no correlation with female patients and patients 60 years or younger. Moreover, high level of ATG4B was positively associated with increased mortality risk in patients with advanced AJCC stages (III and IV) and lymph node invasion (N1 and N2) for both overall survival and disease-free survival. Nevertheless, high level of pS383/392-ATG4B was positively correlated with increased mortality risk in patients with early AJCC stages (I and II) and without lymph node invasion (N0). In addition, silencing ATG4B attenuated migration, invasion, and further enhanced the cytotoxic effects of chemotherapeutic drugs in two and three-dimensional cultures of CRC cells. CONCLUSIONS: Our results suggest that ATG4B and pS383/392-ATG4B might be suitable biomarkers and therapeutic targets for CRC.

The Role of Exosomes in Pancreatic Ductal Adenocarcinoma Progression and Their Potential as Biomarkers.

Pancreatic ductal adenocarcinoma (PDAC), the most common pancreatic malignancy, is an aggressive and lethal cancer with a dismal five-year survival rate. Despite remarkable improvements in cancer therapeutics, the clinical outcome of PDAC patients remains poor due to late diagnosis of the disease. This highlights the importance of early detection, wherein biomarker evaluation including exosomes would be helpful. Exosomes, small extracellular vesicles (sEVs), are cell-secreted entities with diameters ranging from 50 to 150 nm that deliver cellular contents (e.g., proteins, lipids, and nucleic acids) from parent cells to regulate the cellular processes of targeted cells. Recently, an increasing number of studies have reported that exosomes serve as messengers to facilitate stromal-immune crosstalk within the PDAC tumor microenvironment (TME), and their contents are indicative of disease progression. Moreover, evidence suggests that exosomes with specific surface markers are capable of distinguishing patients with PDAC from healthy individuals. Detectable exosomes in bodily fluids (e.g., blood, urine, saliva, and pancreatic juice) are omnipresent and may serve as promising biomarkers for improving early detection and evaluating patient prognosis. In this review, we shed light on the involvement of exosomes and their cargos in processes related to disease progression, including chemoresistance, angiogenesis, invasion, metastasis, and immunomodulation, and their potential as prognostic markers. Furthermore, we highlight feasible clinical applications and the limitations of exosomes in liquid biopsies as tools for early diagnosis as well as disease monitoring. Taking advantage of exosomes to improve diagnostic capacity may provide hope for PDAC patients, although further investigation is urgently needed.

Inflammation-related pyroptosis, a novel programmed cell death pathway, and its crosstalk with immune therapy in cancer treatment.

In recent decades, chemotherapies targeting apoptosis have emerged and demonstrated remarkable achievements. However, emerging evidence has shown that chemoresistance is mediated by impairing or bypassing apoptotic cell death. Several novel types of programmed cell death, such as ferroptosis, necroptosis, and pyroptosis, have recently been reported to play significant roles in the modulation of cancer progression and are considered a promising strategy for cancer treatment. Thus, the switch between apoptosis and pyroptosis is also discussed. Cancer immunotherapy has gained increasing attention due to breakthroughs in immune checkpoint inhibitors; moreover, ferroptosis, necroptosis, and pyroptosis are highly correlated with the modulation of immunity in the tumor microenvironment. Compared with necroptosis and ferroptosis, pyroptosis is the primary mechanism for host defense and is crucial for bridging innate and adaptive immunity. Furthermore, recent evidence has demonstrated that pyroptosis exerts benefits on cancer immunotherapies, including immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T-cell therapy (CAR-T). Hence, in this review, we elucidate the role of pyroptosis in cancer progression and the modulation of immunity. We also summarize the potential small molecules and nanomaterials that target pyroptotic cell death mechanisms and their therapeutic effects on cancer.

Sagittal Split Ramus Osteotomy in the Shortest Buccal Bone Marrow Distances of the Mandible on the Coronal Plane.

PURPOSE: This study investigated the relationship between the shortest buccal bone marrow of the ramus and skeletal patterns. MATERIALS AND METHODS: Using cone-beam computed tomography data (specifically, the A point-nasion-B point (ANB) angle), we divided patients into three groups as follows: skeletal class I (0° < ANB < 4°), class II (ANB: ≥4°), and class III (ANB: ≤0°). Sixteen vertical sections in the coronal plane were taken starting from slice 0 (original intact mandibular canal) anteriorly at 2 mm intervals to slice 15 (30 mm). The thickness of the mandible (M) and shortest buccal bone marrow (SBM) were measured. The data of SBM were divided into two groups (SBM ≥ 1 mm and SBM < 1 mm). For each skeletal pattern, an SBM value < 1 mm was considered to indicate a high possibility of postoperative nerve paresthesia and bad split. RESULTS: The three skeletal pattern groups also did not significantly differ in their M values for all sections. The mean SBM values of class III (0.91-2.11 mm) at 6-16 mm anterior to the mandibular foramen were significantly smaller than those of class II (1.53-3.17 mm). Comparing the occurrence ratio of SBM < 1 mm, the highest and lowest probabilities in class III (55% and 21.7%, respectively) were significantly larger at 6-20 mm anterior to the mandibular foramen than those in class II (28.3% and 5%, respectively). CONCLUSION: Class III had a significantly shorter SBM distance and higher SBM occurrence probability than class II at the mandibular ramus region, implying that class III participants are more likely than class II participants to have nerve paresthesia and bad split after sagittal split ramus osteotomy.

Curcumin Metabolite Tetrahydrocurcumin in the Treatment of Eye Diseases.

Curcumin is one of the most valuable natural products due to its pharmacological activities. However, the low bioavailability of curcumin has long been a problem for its medicinal use. Large studies have been conducted to improve the use of curcumin; among these studies, curcumin metabolites have become a relatively new research focus over the past few years. Additionally, accumulating evidence suggests that curcumin or curcuminoid metabolites have similar or better biological activity than the precursor of curcumin. Recent studies focus on the protective role of plasma tetrahydrocurcumin (THC), a main metabolite of curcumin, against tumors and chronic inflammatory diseases. Nevertheless, studies of THC in eye diseases have not yet been conducted. Since ophthalmic conditions play a crucial role in worldwide public health, the prevention and treatment of ophthalmic diseases are of great concern. Therefore, the present study investigated the antioxidative, anti-inflammatory, antiangiogenic, and neuroprotective effects of THC on four major ocular diseases: age-related cataracts, glaucoma, age-related macular degeneration (AMD), and diabetic retinopathy (DR). While this study aimed to show curcumin as a promising potential solution for eye conditions and discusses the involved mechanistic pathways, further work is required for the clinical application of curcumin.

An Increased Plasma Level of ApoCIII-Rich Electronegative High-Density Lipoprotein May Contribute to Cognitive Impairment in Alzheimer's Disease.

High-density lipoprotein (HDL) plays a vital role in lipid metabolism and anti-inflammatory activities; a dysfunctional HDL impairs cholesterol efflux pathways. To understand HDL's role in patients with Alzheimer's disease (AD), we analyzed the chemical properties and function. HDL from AD patients (AD-HDL) was separated into five subfractions, H1-H5, using fast-protein liquid chromatography equipped with an anion-exchange column. Subfraction H5, defined as the most electronegative HDL, was increased 5.5-fold in AD-HDL (23.48 ± 17.83%) in comparison with the control HDL (4.24 ± 3.22%). By liquid chromatography mass spectrometry (LC/MSE), AD-HDL showed that the level of apolipoprotein (apo)CIII was elevated but sphingosine-1-phosphate (S1P)-associated apoM and anti-oxidative paraoxonase 1 (PON1) were reduced. AD-HDL showed a lower cholesterol efflux capacity that was associated with the post-translational oxidation of apoAI. Exposure of murine macrophage cell line, RAW 264.7, to AD-HDL induced a vibrant expression of ganglioside GM1 in colocalization with apoCIII on lipid rafts alongside a concomitant increase of tumor necrosis factor-α (TNF-α) detectable in the cultured medium. In conclusion, AD-HDL had a higher proportion of H5, an apoCIII-rich electronegative HDL subfraction. The associated increase in pro-inflammatory (apoCIII, TNF-α) components might favor Amyloid ß assembly and neural inflammation. A compromised cholesterol efflux capacity of AD-HDL may also contribute to cognitive impairment.

Gel-Based Nanocarrier for Intravesical Chemotherapy Delivery: In Vitro and In Vivo Study.

Intravesical administration of chemotherapeutic agents can enhance drug accumulation in tumors and reduce systemic side effects. Nanocarriers were developed for intravesical administration and exploit the permeation enhancement effect. In vitro permeation evaluation, the drug transdermal amount and accumulation amounts in the tissue of gemcitabine-loaded nanocarriers through biological membrane significantly increased about 14.8~33.0-fold and 1.5~14.1-fold respectively, when compared to a control group of 1% gemcitabine saline solution. In in vivo intravesical administration, the drug accumulation amount in bladder tissue of nanocarrier of 75.2 ± 5.4 µg was revealed as being comparably higher than that of the control group of 44.8 ± 6.4 µg. In confocal laser scanning microscopy imagery, the penetration depth of fluorescent dyes-rhodamine was increased from 80 µm up to 120 µm when a nanocarrier was used. This result implies that the nanocarrier is a promising drug delivery agent for intravesical administration.

Direct Binding of Cisplatin to p22phox, an Endoplasmic Reticulum (ER) Membrane Protein, Contributes to Cisplatin Resistance in Oral Squamous Cell Carcinoma (OSCC) Cells.

Prolonged treatment with cisplatin (CDDP) frequently develops chemoresistance. We have previously shown that p22phox, an endoplasmic reticulum (ER) membrane protein, confers CDDP resistance by blocking CDDP nuclear entry in oral squamous cell carcinoma (OSCC) cells; however, the underlying mechanism remains unresolved. Using a fluorescent dye-labeled CDDP, here we show that CDDP can bind to p22phox in both cell-based and cell-free contexts. Subsequent detection of CDDP-peptide interaction by the Tris-Tricine-based electrophoresis revealed that GA-30, a synthetic peptide matching a region of the cytosolic domain of p22phox, could interact with CDDP. These results were further confirmed by liquid chromatography-mass spectrometry (LC-MS) analysis, from which MA-11, an 11-amino acid subdomain of the GA-30 domain, could largely account for the interaction. Amino acid substitutions at Cys50, Met65 and Met73, but not His72, significantly impaired the binding between CDDP and the GA-30 domain, thereby suggesting the potential CDDP-binding residues in p22phox protein. Consistently, the p22phox point mutations at Cys50, Met65 and Met73, but not His72, resensitized OSCC cells to CDDP-induced cytotoxicity and apoptosis. Finally, p22phox might have binding specificity for the platinum drugs, including CDDP, carboplatin and oxaliplatin. Together, we have not only identified p22phox as a novel CDDP-binding protein, but further highlighted the importance of such a drug-protein interaction in drug resistance.

The Role of Necroptosis in ROS-Mediated Cancer Therapies and Its Promising Applications.

Over the past decades, promising therapies targeting different signaling pathways have emerged. Among these pathways, apoptosis has been well investigated and targeted to design diverse chemotherapies. However, some patients are chemoresistant to these therapies due to compromised apoptotic cell death. Hence, exploring alternative treatments aimed at different mechanisms of cell death seems to be a potential strategy for bypassing impaired apoptotic cell death. Emerging evidence has shown that necroptosis, a caspase-independent form of cell death with features between apoptosis and necrosis, can overcome the predicament of drug resistance. Furthermore, previous studies have also indicated that there is a close correlation between necroptosis and reactive oxygen species (ROS); both necroptosis and ROS play significant roles both under human physiological conditions such as the regulation of inflammation and in cancer biology. Several small molecules used in experiments and clinical practice eliminate cancer cells via the modulation of ROS and necroptosis. The molecular mechanisms of these promising therapies are discussed in detail in this review.

Autophagy Is Deficient and May be Negatively Regulated by SERPINB3 in Middle Ear Cholesteatoma.

HYPOTHESIS: Whereas autophagy has been linked to various human diseases, whether it also plays a role in cholesteatoma is virtually unknown. This study aimed to investigate the activity and regulation of autophagy in cholesteatoma. BACKGROUND: The treatment of middle ear cholesteatoma has been challenging due to an insufficient understanding of the underlying disease mechanism. METHODS: Expression of microtubule-associated protein 1A/1B-light chain 3 (LC3), the autophagy protein marker, and phosphorylated Akt (p-Akt), and mammalian target of rapamycin (p-mTOR), the known autophagy regulators, in fresh retroauricular skin and cholesteatoma tissue samples was analyzed by immunoblotting. The results were further confirmed by immunohistochemistry and statistical analyses. Cell proliferation of primary retroauricular skin- and cholesteatoma-derived fibroblasts was evaluated by methyl thiazol tetrazolium (MTT) assay. Ectopic expression of serine proteinase inhibitor, clade B, member 3 (SERPINB3) in the fibroblasts was achieved by electroporation and the expression was detected by immunoblotting. RESULTS: LC3 expression was significantly decreased in cholesteatoma in most of the 15 paired retroauricular skin/cholesteatoma tissue samples. However, p-Akt and p-mTOR expression in the cholesteatoma samples was not significantly different from that in the control subjects. Immunohistochemical studies further demonstrated an inverse correlation between LC3 expression and cholesteatoma. The cholesteatoma fibroblasts proliferated faster than the retroauricular skin fibroblasts, and had higher SERPINB3 but lower LC3 expression. Furthermore, overexpression of SERPINB3 in the retroauricular skin fibroblasts enhanced cell proliferation and downregulated LC3 expression. CONCLUSION: Autophagy is significantly suppressed in cholesteatoma tissues, which may not involve the Akt/mTOR signaling pathway. More importantly, SERPINB3 may promote cell proliferation and negatively regulate autophagy in cholesteatoma fibroblasts. Together, these findings warrant further investigation into the pathogenic mechanism of cholesteatoma.

The Phenoxyphenol Compound 4-HPPP Selectively Induces Antiproliferation Effects and Apoptosis in Human Lung Cancer Cells through Aneupolyploidization and ATR DNA Repair Signaling.

Lung cancer is a leading cause of cancer death worldwide, and non-small-cell lung cancer (NSCLC) accounts for 85% of lung cancer, which is highly metastatic, leading to the poor survival rate of patients. We recently reported that 4-[4-(4-hydroxyphenoxy)phenoxy]phenol (4-HPPP), a phenoxyphenol, exerts antihepatoma effects by inducing apoptosis and autophagy. In this study, we further examined the effect of 4-HPPP and its analogs on NSCLC cells. Colony formation assays showed that 4-HPPP exerts selective cytotoxicity against NSCLC H1299 cells; furthermore, the inhibitory effect of 4-HPPP on the proliferation and migration of NSCLC cells was validated using an in vivo zebrafish-based tumor xenograft assay. The flow cytometry-based dichlorofluorescein diacetate (DCF-DA) assays indicated that 4-HPPP caused an increase in reactive oxygen species (ROS) in NSCLC cells, and Western blot assays showed that the major ROS scavenging enzymes superoxide dismutases- (SODs-) 1/2 were upregulated, whereas peroxidase (PRX) was downregulated. Furthermore, 4-HPPP caused both aneuploidization and the accumulation of γH2AX, a sensor of DNA damage, as well as the activation of double-strand break (DSB) markers, especially Ataxia-telangiectasia-mutated and Rad3-related (ATR) in NSCLC cells. Our present work suggests that the antiproliferative effects of 4-HPPP on lung cancer cells could be due to its phenoxyphenol structure, and 4-HPPP could be a candidate molecule for treating NSCLC by modulating ROS levels and lowering the threshold of polyploidy-specific cell death in the future.

Unfolded Protein Response (UPR) in Survival, Dormancy, Immunosuppression, Metastasis, and Treatments of Cancer Cells.

The endoplasmic reticulum (ER) has diverse functions, and especially misfolded protein modification is in the focus of this review paper. With a highly regulatory mechanism, called unfolded protein response (UPR), it protects cells from the accumulation of misfolded proteins. Nevertheless, not only does UPR modify improper proteins, but it also degrades proteins that are unable to recover. Three pathways of UPR, namely PERK, IRE-1, and ATF6, have a significant role in regulating stress-induced physiological responses in cells. The dysregulated UPR may be involved in diseases, such as atherosclerosis, heart diseases, amyotrophic lateral sclerosis (ALS), and cancer. Here, we discuss the relation between UPR and cancer, considering several aspects including survival, dormancy, immunosuppression, angiogenesis, and metastasis of cancer cells. Although several moderate adversities can subject cancer cells to a hostile environment, UPR can ensure their survival. Excessive unfavorable conditions, such as overloading with misfolded proteins and nutrient deprivation, tend to trigger cancer cell death signaling. Regarding dormancy and immunosuppression, cancer cells can survive chemotherapies and acquire drug resistance through dormancy and immunosuppression. Cancer cells can also regulate the downstream of UPR to modulate angiogenesis and promote metastasis. In the end, regulating UPR through different molecular mechanisms may provide promising anticancer treatment options by suppressing cancer proliferation and progression.

AICAR Induces Apoptosis and Inhibits Migration and Invasion in Prostate Cancer Cells Through an AMPK/mTOR-Dependent Pathway.

Current clinical challenges of prostate cancer management are to restrict tumor growth and prohibit metastasis. AICAR (5-aminoimidazole-4-carbox-amide-1-ß-d-ribofuranoside), an AMP-activated protein kinase (AMPK) agonist, has demonstrated antitumor activities for several types of cancers. However, the activity of AICAR on the cell growth and metastasis of prostate cancer has not been extensively studied. Herein we examine the effects of AICAR on the cell growth and metastasis of prostate cancer cells. Cell growth was performed by MTT assay and soft agar assay; cell apoptosis was examined by Annexin V/propidium iodide (PI) staining and poly ADP ribose polymerase (PARP) cleavage western blot, while cell migration and invasion were evaluated by wound-healing assay and transwell assay respectively. Epithelial-mesenchymal transition (EMT)-related protein expression and AMPK/mTOR-dependent signaling axis were analyzed by western blot. In addition, we also tested the effect of AICAR on the chemosensitivity to docetaxel using MTT assay. Our results indicated that AICAR inhibits cell growth in prostate cancer cells, but not in non-cancerous prostate cells. In addition, our results demonstrated that AICAR induces apoptosis, attenuates transforming growth factor (TGF)-ß-induced cell migration, invasion and EMT-related protein expression, and enhances the chemosensitivity to docetaxel in prostate cancer cells through regulating the AMPK/mTOR-dependent pathway. These findings support AICAR as a potential therapeutic agent for the treatment of prostate cancer.

Genetic variants in the circadian rhythm pathway as indicators of prostate cancer progression.

BACKGROUND: To determine the association between circadian pathway genetic variants and the risk of prostate cancer progression. METHODS: We systematically evaluated 79 germline variants in nine circadian pathway genes in a cohort of 458 patients with localized prostate cancer as the discovery phase. We then replicated the significant findings in another cohort of 324 men with more advanced disease. The association of each variant with prostate cancer progression was evaluated by a log-rank test and Cox regression. RESULTS: A single nucleotide polymorphism of the neuronal PAS domain protein 2 (NPAS2) gene (rs6542993 A>T) was found to be associated with a significantly higher risk of disease progression in both localized (P = 0.001) and advanced (P = 0.039) prostate cancer cases. In silico analysis revealed decreased expression levels of NPAS2 in carriers of the T allele of rs6542993 compared with those carrying the A allele. Consistently, downregulation of NPAS2 expression was associated with more aggressive prostate cancer and poor progression-free survival (log-rank P = 0.002). CONCLUSIONS: The NPAS2 rs6542993 polymorphism may be a promising biomarker, and may shed light on the pathways that govern prostate cancer progression.

The Regulations of Deubiquitinase USP15 and Its Pathophysiological Mechanisms in Diseases.

Deubiquitinases (DUBs) play a critical role in ubiquitin-directed signaling by catalytically removing the ubiquitin from substrate proteins. Ubiquitin-specific protease 15 (USP15), a member of the largest subfamily of cysteine protease DUBs, contains two conservative cysteine (Cys) and histidine (His) boxes. USP15 harbors two zinc-binding motifs that are essential for recognition of poly-ubiquitin chains. USP15 is grouped into the same category with USP4 and USP11 due to high degree of homology in an N-terminal region consisting of domains present in ubiquitin-specific proteases (DUSP) domain and ubiquitin-like (UBL) domain. USP15 cooperates with COP9 signalosome complex (CSN) to maintain the stability of cullin-ring ligase (CRL) adaptor proteins by removing the conjugated ubiquitin chains from RBX1 subunit of CRL. USP15 is also implicated in the stabilization of the human papillomavirus type 16 E6 oncoprotein, adenomatous polyposis coli, and IκBα. Recently, reports have suggested that USP15 acts as a key regulator of TGF-ß receptor-signaling pathways by deubiquitinating the TGF-ß receptor itself and its downstream transducers receptor-regulated SMADs (R-SMADs), including SMAD1, SMAD2, and SMAD3, thus activating the TGF-ß target genes. Although the importance of USP15 in pathologic processes remains ambiguous so far, in this review, we endeavor to summarize the literature regarding the relationship of the deubiquitinating action of USP15 with the proteins involved in the regulation of Parkinson's disease, virus infection, and cancer-related signaling networks.

Chronic hepatitis C infection is associated with insulin resistance and lipid profiles.

BACKGROUND AND AIM: Chronic hepatitis C virus (HCV) infection has been suggested to be associated with non-insulin-dependent diabetes mellitus and lipid profiles. This study aimed to investigate the possible relationships of insulin resistance (IR) and lipid profiles with chronic hepatitis C (CHC) patients in Taiwan. METHODS: We enrolled 160 hospital-based CHC patients with liver biopsy and the 480 controlled individuals without CHC and chronic hepatitis B from communities without known history of non-insulin-dependent diabetes mellitus. Fasting plasma glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TGs), alanine aminotransferase, and serum insulin levels, and homeostasis model assessment (HOMA-IR) were tested. RESULTS: When comparing factors between CHC patients, and sex- and age-matched controls who had no HCV infection, patients with HCV infection had a significantly higher alanine aminotransferase level, fasting plasma glucose level, insulin level, and HOMA-IR (P < 0.001, P = 0.023, P = 0.017, and P = 0.011, respectively), and significantly lower TG level (P = 0.023), total cholesterol, and HDL-C and LDL-C levels (all P < 0.001) than 480 controls. In multivariate logistic regression analyses, a low total cholesterol, a low TGs, and a high HOMA-IR are independent factors significantly associated with chronic HCV infection. In the 160 CHC patients (41 patients with high HOMA-IR [> 2.5]), a high body mass index, TGs, and HCV RNA level are independent factors significantly associated with high HOMA-IR in multivariate logistic analyses. CONCLUSIONS: Chronic HCV infection was associated with metabolic characteristics including IR and lipid profile. IR was also associated with virological characteristics.