Correction: Gupta et al. Androgen Receptor Activation Induces Senescence in Thyroid Cancer Cells. 2023, , 2198.

In the original publication [...

Androgen Receptor Activation Induces Senescence in Thyroid Cancer Cells.

Thyroid cancer (TC) is the most common endocrine malignancy, with an approximately three-fold higher incidence in women. TCGA data indicate that androgen receptor (AR) RNA is significantly downregulated in PTC. In this study, AR-expressing 8505C (anaplastic TC) (84E7) and K1 (papillary TC) cells experienced an 80% decrease in proliferation over 6 days of exposure to physiological levels of 5α-dihydrotestosterone (DHT).

Declining BRCA-Mediated DNA Repair in Sperm Aging and its Prevention by Sphingosine-1-Phosphate.

Recent data suggest that paternal age can have major impact on reproductive outcomes, and with increased age, there is increased likelihood of chromosomal abnormalities in the sperm. Here, we studied DNA damage and repair as a function of male aging and assessed whether sphingosine-1-phosphate (S1P), a ceramide-induced death inhibitor, can prevent sperm aging by enhancing DNA double-strand breaks (DSB) repair. We observed a significant increase in DNA damage with age and this increase was associated with a decline in the expression of key DNA DSB repair genes in mouse sperm.

Assessment of DNA Susceptibility to Denaturation as a Marker of Chromatin Structure.

The susceptibility of DNA in situ to denaturation is modulated by its interactions with histone and nonhistone proteins, as well as with other chromatin components related to the maintenance of the 3D nuclear structure. Measurement of DNA proclivity to denature by cytometry provides insight into chromatin structure and thus can be used to recognize cells in different phases of the cell cycle, including mitosis, quiescence (G ), and apoptosis, as well as to identify the effects of drugs that modify chromatin structure. Particularly useful is the method's ability to detect chromatin changes in sperm cells related to DNA fragmentation and infertility.

Detection of Histone H2AX Phosphorylation on Ser-139 as an Indicator of DNA Damage.

This unit describes immunocytochemical detection of histone H2AX phosphorylated on Ser-139 (γH2AX) to reveal DNA damage, particularly when the damage involves the presence of DNA double-strand breaks (DSBs). These breaks often result from DNA damage induced by ionizing radiation or by treatment with anticancer drugs such as DNA topoisomerase inhibitors. Furthermore, DSBs are generated in the course of DNA fragmentation during apoptosis.

Concurrent detection of lysosome and tissue transglutaminase activation in relation to cell cycle position during apoptosis induced by different anticancer drugs.

Described is the new cytometric approach do detect either stimulation or a collapse of lysosomal proton pump (lysosomes rupture) combined with activation of transglutaminase 2 (TG2) during induction of apoptosis. Apoptosis of human lymphoblastoid TK6 cells was induced by combination of 2-deoxyglucose with the isoquinoline alkaloid berberine, by DNA topoisomerase I inhibitor camptothecin, its analog topotecan, topoisomerase II inhibitors etoposide or mitoxantrone, as well as by the cytotoxic anticancer ribonuclease ranpirnase (onconase). Activity of the proton pump of lysosomes was assessed by measuring entrapment and accumulation of the basic fluorochrome acridine orange (AO) resulting in its metachromatic red luminescence (F ) within these organelles.

Upregulation of PD‑L1 expression by resveratrol and piceatannol in breast and colorectal cancer cells occurs via HDAC3/p300‑mediated NF‑κB signaling.

Programmed cell death ligand 1 (PD‑L1) expressed in cancer cells interacting with its receptor programmed cell death 1 (PD‑1) expressed in immune cells represents a regulatory axis linked to the suppression and evasion of host immune functions. The blockade of PD‑1/PD‑L1 interaction using monoclonal antibodies has emerged as an effective therapy for several solid tumors; however, durable response has been observed in a subset of patients with PD‑L1-positive tumors. Thus, the understanding of the mechanisms responsible for the expression of PD‑L1 in tumor cells may help to improve the response to PD‑L1 blockade therapies.

Fluorochrome-Labeled Inhibitors of Caspases: Expedient In Vitro and In Vivo Markers of Apoptotic Cells for Rapid Cytometric Analysis.

Activation of caspases is a characteristic event of apoptosis. Various cytometric methods distinguishing this event have been developed to serve as specific apoptotic markers for the assessment of apoptotic frequency within different cell populations. The method described in this chapter utilizes fluorochrome labeled inhibitors of caspases (FLICA) and is applicable to fluorescence microscopy, flow- and imaging-cytometry as well as to confocal imaging.

ATM Activation and H2AX Phosphorylation Induced by Genotoxic Agents Assessed by Flow- and Laser Scanning Cytometry.

Activation of Ataxia Telangiectasia Mediated protein kinase (ATM) by its phosphorylation on serine 1981 and phosphorylation of histone H2AX on serine 139 (γH2AX) are the key events reporting DNA damage, primarily formation of DNA double strand breaks. These events are detected immunocytochemically in individual cells using phospho-specific Abs. The protocols are presented that describe the methodology of immunofluorescent labeling of cells in conjunction with specific staining of cellular DNA.

DNA Damage Response Resulting from Replication Stress Induced by Synchronization of Cells by Inhibitors of DNA Replication: Analysis by Flow Cytometry.

Cell synchronization is often achieved by transient inhibition of DNA replication. When cultured in the presence of such inhibitors as hydroxyurea, aphidicolin or excess of thymidine the cells that become arrested at the entrance to S-phase upon release from the block initiate progression through S then G and M. However, exposure to these inhibitors at concentrations commonly used to synchronize cells leads to activation of ATR and ATM protein kinases as well as phosphorylation of Ser139 of histone H2AX.

Synergy of 2-deoxy-D-glucose combined with berberine in inducing the lysosome/autophagy and transglutaminase activation-facilitated apoptosis.

Utilizing a variety of flow cytometric methods evidence was obtained indicating that a combination of the glucose analog 2-deoxy-D-glucose (2-dG) and the plant alkaloid berberine (BRB) produces synergistic effect in the induction of apoptosis in human lymphoblastoid TK6 cells. The synergistic effect is seen at concentrations of the drugs at which each of them alone shows no cytotoxicity at all. The data suggest that the combination of these drugs, which are known in terms of their overall toxicity, side effects and pharmacokinetics may be considered for further studies as chemopreventive and cancer treatment modalities.

Assessment of red blood cell distribution width as a prognostic marker in chronic lymphocytic leukemia.

Red blood cell distribution width (RDW) is a quantitative measure of the variability in size of circulating erythrocytes. It was recently reported that RDW is a prognostic factor for infection diseases, cardiovascular and pulmonary diseases, as well as some neoplasms. Moreover, RDW is remarkably strong predictor of longevity, including all causes of death, for adults aged 45 years and older.

Designing a broad-spectrum integrative approach for cancer prevention and treatment.

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.

mTOR inhibitors sensitize thyroid cancer cells to cytotoxic effect of vemurafenib.

Treatment options for advanced metastatic thyroid cancer patients are limited. Vemurafenib, a BRAFV600E inhibitor, has shown promise in clinical trials although cellular resistance occurs. Combination therapy that includes BRAFV600E inhibition and avoids resistance is a clinical need.

Broad targeting of resistance to apoptosis in cancer.

Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer.

Sustained proliferation in cancer: Mechanisms and novel therapeutic targets.

Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth.

Genomic instability in human cancer: Molecular insights and opportunities for therapeutic attack and prevention through diet and nutrition.

Genomic instability can initiate cancer, augment progression, and influence the overall prognosis of the affected patient. Genomic instability arises from many different pathways, such as telomere damage, centrosome amplification, epigenetic modifications, and DNA damage from endogenous and exogenous sources, and can be perpetuating, or limiting, through the induction of mutations or aneuploidy, both enabling and catastrophic. Many cancer treatments induce DNA damage to impair cell division on a global scale but it is accepted that personalized treatments, those that are tailored to the particular patient and type of cancer, must also be developed.

Therapeutic targeting of replicative immortality.

One of the hallmarks of malignant cell populations is the ability to undergo continuous proliferation. This property allows clonal lineages to acquire sequential aberrations that can fuel increasingly autonomous growth, invasiveness, and therapeutic resistance. Innate cellular mechanisms have evolved to regulate replicative potential as a hedge against malignant progression.

Cancer prevention and therapy through the modulation of the tumor microenvironment.

Cancer arises in the context of an in vivo tumor microenvironment. This microenvironment is both a cause and consequence of tumorigenesis. Tumor and host cells co-evolve dynamically through indirect and direct cellular interactions, eliciting multiscale effects on many biological programs, including cellular proliferation, growth, and metabolism, as well as angiogenesis and hypoxia and innate and adaptive immunity.

Immune evasion in cancer: Mechanistic basis and therapeutic strategies.

Cancer immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Although considerable progress has been made in understanding how cancers evade destructive immunity, measures to counteract tumor escape have not kept pace. There are a number of factors that contribute to tumor persistence despite having a normal host immune system.

Evasion of anti-growth signaling: A key step in tumorigenesis and potential target for treatment and prophylaxis by natural compounds.

The evasion of anti-growth signaling is an important characteristic of cancer cells. In order to continue to proliferate, cancer cells must somehow uncouple themselves from the many signals that exist to slow down cell growth. Here, we define the anti-growth signaling process, and review several important pathways involved in growth signaling: p53, phosphatase and tensin homolog (PTEN), retinoblastoma protein (Rb), Hippo, growth differentiation factor 15 (GDF15), AT-rich interactive domain 1A (ARID1A), Notch, insulin-like growth factor (IGF), and Krüppel-like factor 5 (KLF5) pathways.

Broad targeting of angiogenesis for cancer prevention and therapy.

Deregulation of angiogenesis--the growth of new blood vessels from an existing vasculature--is a main driving force in many severe human diseases including cancer. As such, tumor angiogenesis is important for delivering oxygen and nutrients to growing tumors, and therefore considered an essential pathologic feature of cancer, while also playing a key role in enabling other aspects of tumor pathology such as metabolic deregulation and tumor dissemination/metastasis. Recently, inhibition of tumor angiogenesis has become a clinical anti-cancer strategy in line with chemotherapy, radiotherapy and surgery, which underscore the critical importance of the angiogenic switch during early tumor development.

In search of antiaging modalities: evaluation of mTOR- and ROS/DNA damage-signaling by cytometry.

This review presents the evidence in support of the IGF-1/mTOR/S6K1 signaling as the primary factor contributing to aging and cellular senescence. Reviewed are also specific interactions between mTOR/S6K1 and ROS-DNA damage signaling pathways. Outlined are critical sites along these pathways, including autophagy, as targets for potential antiaging (gero-suppressive) and/or chemopreventive agents.

DNA damage signaling, impairment of cell cycle progression, and apoptosis triggered by 5-ethynyl-2'-deoxyuridine incorporated into DNA.

The "click chemistry" approach utilizing 5-ethynyl-2'-deoxyuridine (EdU) as a DNA precursor was recently introduced to assess DNA replication and adapted to flow- and imaging-cytometry. In the present study, we observed that EdU, once incorporated into DNA, induces DNA damage signaling (DDS) such as phosphorylation of ATM on Ser1981, of histone H2AX on Ser139, of p53 on Ser15, and of Chk2 on Thr68. It also perturbs progression of cells through the cell cycle and subsequently induces apoptosis.