Aquaporin 8 involvement in human cervical cancer SiHa migration via the EGFR-Erk1/2 pathway

Reducing the Invasiveness of Low- and High-Grade Endometrial Cancers in Both Primary Human Cancer Biopsies and Cell Lines by the Inhibition of Aquaporin-1 Channels

Aquaporin (AQP) channels in endometrial cancer (EC) cells are of interest as pharmacological targets to reduce tumor progression. A panel of compounds, including AQP1 ion channel inhibitors (AqB011 and 5-(phenoxymethyl) furan-2-carbaldehyde, PMFC), were used to test the hypothesis that inhibition of key AQPs can limit the invasiveness of low- and high-grade EC cells. We evaluated the effects on transwell migration in EC cell lines (Ishikawa, MFE-280) and primary EC cells established from surgical tissues (n = 8). Quantitative PCR uncovered classes of AQPs not previously reported in EC that are differentially regulated by hormonal signaling. With estradiol, Ishikawa showed increased AQPs 5, 11, 12, and decreased AQPs 0 and 4; MFE-280 showed increased AQPs 0, 1, 3, 4, 8, and decreased AQP11. Protein expression was confirmed by Western blot and immunocytochemistry. AQPs 1, 4, and 11 were colocalized with plasma membrane marker; AQP8 was intracellular in Ishikawa and not detectable in MFE-280. AQP1 ion channel inhibitors (AqB011; PMFC) reduced invasiveness of EC cell lines in transwell chamber and spheroid dispersal assays. In Ishikawa cells, transwell invasiveness was reduced ~41% by 80 µM AqB011 and ~55% by 0.5 mM 5-PMFC. In MFE-280, 5-PMFC inhibited invasion by ~77%. In contrast, proposed inhibitors of AQP water pores (acetazolamide, ginsenoside, KeenMind, TGN-020, IMD-0354) were not effective. Treatments of cultured primary EC cells with AqB011 or PMFC significantly reduced the invasiveness of both low- and high-grade primary EC cells in transwell chambers. We confirmed the tumors expressed moderate to high levels of AQP1 detected by immunohistochemistry, whereas expression levels of AQP4, AQP8, and AQP11 were substantially lower. The anti-invasive potency of AqB011 treatment for EC tumor tissues showed a positive linear correlation with AQP1 expression levels. In summary, AQP1 ion channels are important for motility in both low- and high-grade EC subtypes. Inhibition of AQP1 is a promising strategy to inhibit EC invasiveness and improve patient outcomes.

Exploring the Phytochemical Profile and Biological Activities of Clerodendrum infortunatum

Clerodendrum infortunatum (C. infortunatum), the hill glory bower, is reputed as the prodigious treasure for Indian folk medicine. The study has focused on exploring the phytochemistry and antitumor potential of the C. infortunatum root extract in vitro and in vivo. The ethyl acetate root extract has demonstrated the highest cytotoxicity in a series of nine human tumor cell lines. Further fractionation of the same has yielded seven compounds. The structures of these compounds were confirmed with spectroscopic techniques. Considering the toxicity observed with the crude extract, cytotoxicity of these compounds was further assessed in two breast carcinoma cell lines (MCF-7[ER/PR-positive HER2-negative] and MDA-MB-231 [ER/PR/HER2-negative]) and in two cervical cancer [human papilloma virus (HPV)-negative C33A and HPV-positive SiHa] cell lines. Betulinic acid (BA) was found as the active principle contributing the cytotoxic activity, and cervical cancer cell lines documented the minimum IC₅₀ value in 24 h. In order to validate the in vitro experimental data, we have established a xenograft model of HPV-positive cervical cancer in female NOD/SCID mice treated with BA using doxorubicin as the positive control. BA treatment gradually reduced the tumor size, maintaining healthy hematological and biochemical parameters, and improved the survival rate of tumor-bearing mice considerably. Thus, our findings suggest that the C. infortunatum root extract has a promising anticancer property against HPV-positive cervical cancer and supports its usage by traditional healers for treating cervical cancer.

Aquaporins in Tumor

Recent researches have demonstrated that aquaporins (AQPs), including water-selective channels, aquaglyceroporins and superaquaporins, are generally expressed in various tumors, such as lung, colorectal, liver, brain, breast tumors, etc. Therefore, it is imperative to study the accurate relationship between AQPs and tumor, which may provide innovative approaches to treat and prevent tumor development. In this chapter, we mainly reviewed the expression and pathophysiological function of AQPs in tumor, and summarize recent work on AQPs in tumor. Although, the underlying mechanism of AQP in tumor is not very clear, growing evidences suggest that cell migration, adhesion, angiogenesis, and division contribute to tumor development, in which AQPs might be involved. Therefore, it is still necessary to conduct further studies to determine the specific roles of AQPs in the tumor.

Aquaporins in insulin resistance and diabetes: More than channels!

Aquaporins (AQPs) are part of the family of the integral membrane proteins. Their function is dedicated to the transport of water, glycerol, ammonia, urea, H₂O₂, and other small molecules across the biological membranes. Although for many years they were scarcely considered, AQPs have a relevant role in the development of many diseases. Recent discoveries suggest, that AQPs may play an important role in the process of fat accumulation and regulation of oxidative stress, two crucial aspects of insulin resistance and type-2 diabetes (T2D).

Insulin resistance (IR) and T2D are multi-faceted systemic diseases with multiple connections to obesity and other comorbidities such as hypertension, dyslipidemia and metabolic syndrome. Both IR and T2D transcends different tissues and organs, creating the maze of mutual relationships between adipose fat depots, skeletal muscle, liver and other insulin-sensitive organs. AQPs with their heterogenous properties, distinctive tissue distribution and documented involvement in both the lipid metabolism and regulation of the oxidative stress appear to be feasible candidates in the search for the explanation to this third-millennium plague. A lot of research has been assigned to adipose tissue AQP7 and liver tissue AQP9, clarifying their relationship and coordinated work in the induction of hepatic insulin resistance. Novel research points also to other aquaporins, such as AQP11 which may be associated with the induction of insulin resistance and T2D through its involvement in hydrogen peroxide transport.

In this review we collected recent discoveries in the field of AQP's involvement in the insulin resistance and T2D. Novel paths which connect AQPs with metabolic disorders can give new fuel to the research on obesity, insulin resistance and T2D - one of the most worrying problems of the modern society.

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Presentation of the current knowledge on the involvement of aquaporins in disease state.

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Overview on latest research regarding insulin resistance and AQPs.

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Conceptualisation of an AQPs network involved regulation of lipid-related metabolism.

A Comprehensive Understanding of the Anticancer Mechanisms of FDY2004 Against Cervical Cancer Based on Network Pharmacology

Herbal drugs are continuously being developed and used as effective therapeutics for various cancers, such as cervical cancer (CC); however, their mechanisms of action at a systemic level have not been explored fully. To study such mechanisms, we conducted a network pharmacological investigation of the anti-CC mechanisms of FDY2004, an herbal drug consisting of Moutan Radicis Cortex, Persicae Semen , and Rhei Radix et Rhizoma. We found that FDY2004 inhibited the viability of human CC cells. By performing pharmacokinetic evaluation and network analysis of the phytochemical components of FDY2004, we identified 29 bioactive components and their 116 CC-associated pharmacological targets. Gene ontology enrichment analysis showed that the modulation of cellular functions, such as apoptosis, growth, proliferation, and survival, might be mediated through the FDY2004 targets. The therapeutic targets were also key components of CC-associated oncogenic and tumor-suppressive pathways, including PI3K-Akt, human papillomavirus infection, IL-17, MAPK, TNF, focal adhesion, and viral carcinogenesis pathways. In conclusion, our data present a comprehensive insight for the mechanisms of the anti-CC properties of FDY2004.

Targeting Aquaporins in Novel Therapies for Male and Female Breast and Reproductive Cancers

Aquaporins are membrane channels in the broad family of major intrinsic proteins (MIPs), with 13 classes showing tissue-specific distributions in humans. As key physiological modulators of water and solute homeostasis, mutations, and dysfunctions involving aquaporins have been associated with pathologies in all major organs. Increases in aquaporin expression are associated with greater severity of many cancers, particularly in augmenting motility and invasiveness for example in colon cancers and glioblastoma. However, potential roles of altered aquaporin (AQP) function in reproductive cancers have been understudied to date. Published work reviewed here shows distinct classes aquaporin have differential roles in mediating cancer metastasis, angiogenesis, and resistance to apoptosis. Known mechanisms of action of AQPs in other tissues are proving relevant to understanding reproductive cancers. Emerging patterns show AQPs 1, 3, and 5 in particular are highly expressed in breast, endometrial, and ovarian cancers, consistent with their gene regulation by estrogen response elements, and AQPs 3 and 9 in particular are linked with prostate cancer. Continuing work is defining avenues for pharmacological targeting of aquaporins as potential therapies to reduce female and male reproductive cancer cell growth and invasiveness.

Systems Pharmacology Study of the Anticervical Cancer Mechanisms of FDY003

Increasing data support that herbal medicines are beneficial in the treatment of cervical cancer; however, their mechanisms of action remain to be elucidated. In the current study, we used a systems pharmacology approach to explore the pharmacological mechanisms of FDY003, an anticancer herbal formula comprising Lonicera japonica Thunberg, Artemisia capillaris Thunberg, and Cordyceps militaris (Linn.) Link, in the treatment of cervical cancer. Through the pharmacokinetic assessment of absorption-distribution-metabolism-excretion characteristics, we found 18 active compounds that might interact with 106 cervical cancer-related targets responsible for the pharmacological effects. FDY003 targets were significantly associated with gene ontology terms related to the regulation of cellular behaviors, including cell proliferation, cell cycle processes, cell migration, cell apoptosis, cell death, and angiogenesis. The therapeutic targets of the herbal drug were further enriched in various oncogenic pathways that are implicated in the tumorigenesis and progression of cervical cancer, including the phosphatidylinositol 3-kinase, mitogen-activated protein kinase, focal adhesion, human papillomavirus infection, and tumor necrosis factor signaling pathways. Our study provides a systematic approach to explore the anticancer properties of herbal medicines against cervical cancer.

Combined Systematic Review and Transcriptomic Analyses of Mammalian Aquaporin Classes 1 to 10 as Biomarkers and Prognostic Indicators in Diverse Cancers

Aquaporin (AQP) channels enable regulated transport of water and solutes essential for fluid homeostasis, but they are gaining attention as targets for anticancer therapies. Patterns of AQP expression and survival rates for patients were evaluated by systematic review (PubMed and Embase) and transcriptomic analyses of RNAseq data (Human Protein Atlas database). Meta-analyses confirmed predominantly negative associations between AQP protein and RNA expression levels and patient survival times, most notably for AQP1 in lung, breast and prostate cancers; AQP3 in esophageal, liver and breast cancers; and AQP9 in liver cancer. Patterns of AQP expression were clustered for groups of cancers and associated with risk of death. A quantitative transcriptomic analysis of AQP1-10 in human cancer biopsies similarly showed that increased transcript levels of AQPs 1, 3, 5 and 9 were most frequently associated with poor survival. Unexpectedly, increased AQP7 and AQP8 levels were associated with better survival times in glioma, ovarian and endometrial cancers, and increased AQP11 with better survival in colorectal and breast cancers. Although molecular mechanisms of aquaporins in pathology or protection remain to be fully defined, results here support the hypothesis that overexpression of selected classes of AQPs differentially augments cancer progression. Beyond fluid homeostasis, potential roles for AQPs in cancers (suggested from an expanding appreciation of their functions in normal tissues) include cell motility, membrane process extension, transport of signaling molecules, control of proliferation and apoptosis, increased mechanical compliance, and gas exchange. AQP expression also has been linked to differences in sensitivity to chemotherapy treatments, suggesting possible roles as biomarkers for personalized treatments. Development of AQP pharmacological modulators, administered in cancer-specific combinations, might inspire new interventions for controlling malignant carcinomas.

Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Erlotinib Induces Dry Skin via Decreased in Aquaporin-3 Expression

An adverse reaction of dry skin occurs frequently during treatment with anticancer epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). In this study, we conducted basic research to clarify the mechanism of EGFR-TKI-induced dry skin and propose new treatments or preventative measures. Dermal water content was significantly lower in the erlotinib-treated mice than in the control group. An assessment of the expression levels of functional genes in the skin revealed that only the expression of the water channel aquaporin-3 (AQP3) was significantly decreased in the erlotinib-treated group. When erlotinib was added to epidermal keratinocyte HaCaT cells, the expression levels of both AQP3 mRNA and protein decreased. Erlotinib treatment also significantly decreased the expression levels of phospho-EGFR and phospho-extracellular signal-regulated kinase (ERK), both in HaCaT cells and mouse skin. Dry skin due to erlotinib may be caused by the decreased expression of AQP3 in the skin, thereby limiting water transport from the vascular side to the corneum side. The decrease in AQP3 may also be attributable to ERK suppression via inhibition of EGFR activity by erlotinib. Therefore, substances that increase AQP3 expression may be effective for erlotinib-induced dry skin.

Mechanisms of Aquaporin-Facilitated Cancer Invasion and Metastasis

Cancer is a leading cause of death worldwide, and its incidence is rising with numbers expected to increase 70% in the next two decades. The fact that current mainline treatments for cancer patients are accompanied by debilitating side effects prompts a growing demand for new therapies that not only inhibit growth and proliferation of cancer cells, but also control invasion and metastasis. One class of targets gaining international attention is the aquaporins, a family of membrane-spanning water channels with diverse physiological functions and extensive tissue-specific distributions in humans. Aquaporins−1,−2,−3,−4,−5,−8, and−9 have been linked to roles in cancer invasion, and metastasis, but their mechanisms of action remain to be fully defined. Aquaporins are implicated in the metastatic cascade in processes of angiogenesis, cellular dissociation, migration, and invasion. Cancer invasion and metastasis are proposed to be potentiated by aquaporins in boosting tumor angiogenesis, enhancing cell volume regulation, regulating cell-cell and cell-matrix adhesions, interacting with actin cytoskeleton, regulating proteases and extracellular-matrix degrading molecules, contributing to the regulation of epithelial-mesenchymal transitions, and interacting with signaling pathways enabling motility and invasion. Pharmacological modulators of aquaporin channels are being identified and tested for therapeutic potential, including compounds derived from loop diuretics, metal-containing organic compounds, plant natural products, and other small molecules. Further studies on aquaporin-dependent functions in cancer metastasis are needed to define the differential contributions of different classes of aquaporin channels to regulation of fluid balance, cell volume, small solute transport, signal transduction, their possible relevance as rate limiting steps, and potential values as therapeutic targets for invasion and metastasis.

Effect of selective inhibition of aquaporin 1 on chemotherapy sensitivity of J82 human bladder cancer cells

The occurrence of resistance to mitomycin C (MMC) often limits its clinical effectiveness. Combination therapy thus is employed to overcome this treatment resistance. The present study aimed to establish a novel J82 bladder cancer cell line so as to study the effect of inhibition of aquaporin 1 (AQP-1) on chemotherapy sensitivity of J82 bladder cancer cells. A novel J82 bladder cancer cell line whose expression of AQP-1 is inhibited was established through transfection of J82 cells with newly constructed recombinant plasmid. The resulting cell line was designated J82-short hairpin (sh)AQP1 and was subjected to further analyses together with J82 cell line. Reverse transcription-polymerase chain reaction was used to quantify the expression of AQP-1mRNA in the cells; cell viability was analyzed with MTT assay and apoptosis was measured by flow cytometry. The expression of cell proliferation and cell apoptosis-associated proteins, proliferating cell nuclear antigen (PCNA), B cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax) and caspase-3, were detected by Western blot. A statistically significant decrease in the transcription and expression of AQP1 was observed in the J82-shAQP1 cells as compared with J82 cells. J82-shAQP1 cells treated by MMC, also had a lower cell viability than J82 cells treated by MMC and showed enhanced apoptosis. Western blot analysis revealed J82-shAQP1 cells treated by MMC had less expression of PCNA, lower bcl-2/Bax ratio and more expression of caspase-3 as compared with the J82 cells treated by MMC. Selective inhibition of AQP-1 enhanced MMC chemotherapy sensitivity of J82 bladder cancer cells, suggesting combination of AQP-1 inhibition with MMC treatment as a promising treatment strategy to overcome bladder cancer treatment resistance.

The involvement of aquaporin 1 in the hepatopulmonary syndrome rat serum-induced migration of pulmonary arterial smooth muscle cells via the p38-MAPK pathway

Hepatopulmonary syndrome (HPS) is characterized by arterial oxygenation defects induced by intrapulmonary vascular dilation (IPVD). Pulmonary vascular remodeling (PVR) is an important pathological feature of IPVD; however, the details regarding the underlying mechanisms of this process remain undefined. Recent studies have determined that the abnormal migration of pulmonary arterial smooth muscle cells (PASMCs) plays a role in the pathogenesis of the PVR associated with HPS. Additionally, aquaporin 1 (AQP1) not only functions as a water channel molecule but also promotes cell migration by facilitating water transport in the lamellipodia of migrating cells. Common bile duct ligation (CBDL) rat is a well-accepted HPS model; we determined that the immunoperoxidase labeling of AQP1 was enhanced in the media of the pulmonary vessels in CBDL rats. HPS rat serum mediated the overexpression of AQP1 in PASMCs, and also upregulated PASMC migration. Small interfering RNAs (siRNAs) that targeted rat AQP1 caused significant downregulation of AQP1, which resulted in decreased PASMC migration. Furthermore, the inhibition of the p38-MAPK pathway abolished AQP1-dependent PASMC migration. In conclusion, this study demonstrated that AQP1 enhanced PASMC migration via the p38-MAPK pathway in rat with HPS and may represent a potential therapeutic strategy in the setting of pulmonary vascular remodeling associated with HPS.

Expression of aquaporin 1 in bladder uroepithelial cell carcinoma and its relevance to recurrence

OBJECTIVES

To explore the expression of aquaporin 1 (AQP1) in bladder uroepithelium cell carcinoma (BUCC) and its relevance to recurrence.

MATERIALS AND METHODS

Tissue samples from 45 BUCC patients who underwent total cystectomy or transurethral resection of bladder tumor (TURBT) and from 40 patients with non-bladder cancers who underwent special detection or treatments were collected. The level of expression of AQP1 in BUCC tissues and normal bladder tissues was assessed by immunohistochemistry so as to analyze the relevance to pathological patterns and time of recurrence in BUCC patients.

RESULTS

The expression levels of AQP1 normal bladder tissues and BUCC tissues were 2.175±0.693 and 3.689±0.701, respectively, and the difference was significant (t=9.99, P<0.0001). Marked increase was noted with BUCC histological grade and pathological stage (P<0.01). Moreover, the expression of AQP1 was evidently higher in cancerous tissues with lymph node metastasis than in those without (P<0.01). With short-term recurrence, the positive cell expression rate of AQP1 was higher in primary tissues, which increased obviously after recurrence. Additionally, the recurrent time of BUCC was negatively associated with the positive cell expression rate of AQP1 and the difference between the expression of AQP1 before and after recurrence (r=-0.843, F=39.302, P=0.000; r=-0.829, F=35.191, P=0.000).

CONCLUSIONS

AQP1, which reflects the grade, stage, lymph node metastasis and recurrence of BUCC, has potential guiding significance in the diagnosis and treatment of bladder cancarcinoma.

Modification of aquaporin expression in response to fenretinide-induced transdifferentiation of ARPE-19 cells into neuronal-like cells

PURPOSE

The goal of this study was to investigate the modifications of aquaporin (AQP) expression in ARPE-19 cells in response to fenretinide-induced transdifferentiation into neuronal-like cells

METHODS

ARPE-19 cells were treated daily for 7 days with 3 μm fenretinide or dimethyl sulphoxide as control. mRNA and protein expression were evaluated by real-time quantitative PCR, Western blot analysis and immunofluorescence.

RESULTS

Control ARPE-19 cells expressed AQP1, AQP4, AQP6 and AQP11 at the mRNA level, but only AQP4, AQP6 and AQP11 at the protein level. Fenretinide induced the transdifferentiation of ARPE-19 cells into neuronal-like cells. Indeed, fenretinide induced morphological changes similar to neurons characterized by elongated cell body and the formation of neurite branching. Moreover, ARPE-19 cells transdifferentiated to neuron-like cells were characterized by significant decrease in retinal pigmented epithelium markers, for example cytokeratin 8 and cellular retinaldehyde-binding protein, as well as an increase in neuronal markers such as synaptophysin and calretinin. AQP4 expression, at both mRNA and protein levels, and AQP6 expression, only at protein level, were significantly decreased in ARPE-19 cells transdifferentiated into neuronal-like cells.

CONCLUSIONS

The expression of AQP4 and AQP6 is downregulated during fenretinide-induced transdifferentiation.

Role of epidermal growth factor in pathogenesis of uterine leiomyomas

OBJECTIVE

To investigate the role of epidermal growth factor (EGF) in the pathogenesis of uterine leiomyomas.

METHODS

Human myometrial smooth muscle cells (HM-SMCs) and smooth muscle cells of human uterine leiomyomas (HL-SMCs) were separated from patients' specimens and cultured. After processed by EGF or PD98059 (inhibitor of MKK/MEK) +EGF, the proliferation rate of both SMCs was detected by BrdU method and the phosphorylation level of p44/42 mitogen-activated protein kinase (MAPK) was determined by Western-blot. After different processing time by EGF, the phosphorylation levels of p44/42 MAPK and AKT and p27 expression level in both SMCs were detected by Western-blot.

RESULTS

EGF could significantly promote HL-SMCs proliferation and PD98059 could inhibit this effect (P<0.05); besides, PD98059 could inhibit the increase of the phosphorylation level of p44/42 MAPK in both SMCs induced by EGF. When the processing time by EGF was over 15min, the phosphorylation levels of p44/42 MAPK and AKT in both SMCs decreased sharply and were close to zero; p27 expression in HM-SMCs raised significantly while the upregulation in HL-SMCs was little.

CONCLUSIONS

EGF could not cause activation of EGFR because of the dephosphorylation of p44/42 MAPK and AKT in HL-SMCs, which caused p27 expression insufficiently and cell cycle dysregulation.