Radiation-induced posttranscriptional control of M6P/IGF2r expression in breast cancer cell lines

Lysosomes, curcumin, and anti-tumor effects: how are they linked?

Curcumin is a natural active ingredient from traditional Chinese medicine (TCM) that has multi-target characteristics to exert extensive pharmacological activities and thus has been applied in the treatment of various diseases such as cancer, cardiovascular diseases, nervous system, and autoimmune disorders. As an important class of membranous organelles in the intracellular membrane system, lysosomes are involved in biological processes such as programmed cell death, cell metabolism, and immune regulation, thus affecting tumor initiation and progression. It has been shown that curcumin can modulate lysosomal function through the aforementioned pathways, thereby affecting tumor proliferation, invasion, metastasis, drug resistance, and immune function. This review briefly elaborated the regulatory mechanisms of lysosome biogenesis and summarized curcumin-related studies with its anti-tumor effect, providing a reference for the clinical application of curcumin and anti-tumor research targeting lysosomes.

Altered long non-coding RNAs expression in normal and diseased primary human airway epithelial cells exposed to diesel exhaust particles

BACKGROUND

Exposure to diesel exhaust particles (DEP) has been linked to a variety of adverse health effects, including increased morbidity and mortality from cardiovascular diseases, chronic obstructive pulmonary disease (COPD), metabolic syndrome, and lung cancer. The epigenetic changes caused by air pollution have been associated with increased health risks. However, the exact molecular mechanisms underlying the lncRNA-mediated pathogenesis induced by DEP exposure have not been revealed.

METHODS

Through RNA-sequencing and integrative analysis of both mRNA and lncRNA profiles, this study investigated the role of lncRNAs in altered gene expression in healthy and diseased human primary epithelial cells (NHBE and DHBE-COPD) exposed to DEP at a dose of 30 μg/cm2.

RESULTS

We identified 503 and 563 differentially expressed (DE) mRNAs and a total of 10 and 14 DE lncRNAs in NHBE and DHBE-COPD cells exposed to DEP, respectively. In both NHBE and DHBE-COPD cells, enriched cancer-related pathways were identified at mRNA level, and 3 common lncRNAs OLMALINC, AC069234.2, and LINC00665 were found to be associated with cancer initiation and progression. In addition, we identified two cis-acting (TMEM51-AS1 and TTN-AS1) and several trans-acting lncRNAs (e.g. LINC01278, SNHG29, AC006064.4, TMEM51-AS1) only differentially expressed in COPD cells, which could potentially play a role in carcinogenesis and determine their susceptibility to DEP exposure.

CONCLUSIONS

Overall, our work highlights the potential importance of lncRNAs in regulating DEP-induced gene expression changes associated with carcinogenesis, and individuals suffering from COPD are likely to be more vulnerable to these environmental triggers.

Establishment of a type II insulin-like growth factor receptor gene site-integrated SKBR3 cell line using CRISPR/Cas9

Human epidermal growth factor receptor 2 (HER-2)⁺ breast cancer has a high recurrence rate and a poor prognosis, with drug resistance contributing to disease progression. The present study aimed to establish a SKBR3 cell line with type II insulin-like growth factor receptor (IGR-IIR) gene site integration using the CRISPR/Cas9 system, and to provide a cell model for exploring the mechanism responsible for the effect of IGF-IIR on trastuzumab resistance in HER-2⁺ breast cancer cells. In the present study, six single guide (sg)RNA pairs according to the adeno-associated virus integration site 1 (AAVS1) gene sequence were designed and synthesized, and the Universal CRISPR Activity assay CRISPR/Cas9 rapid construction and activity detection kit was used to connect the annealed oligo with the pCS vector. The sgRNA with the highest efficiency was selected to construct a Cas9/sgRNA expression vector using AsiSI + Bstz17I restriction enzymes to cut IGF-IIR. The fragment was ligated into an human AAVS1-KI vector to construct the IGF-IIR targeting vector. The Cas9/sgRNA and IGF-IIR targeting vectors were electroporated into SKBR3 cells, screened using puromycin and identified via PCR, and the mixed cloned cells generated via IGF-IIR gene targeted integration were obtained. The semi-solid and limited dilution methods were used for monoclonal cell preparation, and the results revealed that a Cas9/sgRNA vector that targeted the AAVS1 was successfully constructed. sgRNA activity detection demonstrated that sgRNA2 had the highest efficiency, while enzyme digestion and sequencing confirmed that the IGF-IIR target vector was successfully constructed. The optimum conditions for electrotransfection were 1,200 V, 20 ms and 2 pulses, and the optimal screening concentration of puromycin was 0.5 µg/ml. Using these conditions, the IGF-IIR targeting vector and pCS-sgRNA2 plasmid were successfully transfected into SKBR3 cells, and PCR identification and sequencing verified the correct genotype of mixed clone fragments. The monoclonal cells proliferate slowly and gradually underwent apoptosis. Overall, the present study successfully obtained a mixed clone cell line with site-specific integration of the IGF-IIR gene at the AAVS1.

The Role of Proinflammatory Cytokine Interleukin-18 in Radiation Injury

Massive radiation-induced inflammatory factors released from injured cells may cause innate and acquired immune reactions that can further result in stress response signal activity-induced local and systemic damage. IL-1 family members IL-1β, IL-18, and IL-33 play key roles in inflammatory and immune responses and have been recognized to have significant influences on the pathogenesis of diseases. IL-1β, IL-18, and IL-33 share similarities of cytokine biology, but differences exist in signaling pathways. A key component of the inflammatory reaction is the inflammasome, which is a caspase-1-containing multiprotein oligomer. Pathological stimuli such as radiation can induce inflammasome and caspase-1 activation, and subsequently cause maturation (activation) of pro-forms of IL-1 and IL-18 upon caspase-1 cleavage. This caspase-1 dependent and IL-1 and IL-18 associated cell damage is defined as pyroptosis. Activated IL-1 and IL-18 as proinflammatory cytokines drive pathology at different immune and inflammatory disorders through Toll-like receptor (TLR) signaling. While the mechanisms of IL-1β-induced pathophysiology of diseases have been well studied, IL-18 has received less attention. The author recently reported that gamma radiation highly increased IL-1β, IL-18 and IL-33 expression in mouse thymus, spleen and/or bone marrow cells; also circulating IL-18 can be used as a radiation biomarker to track radiation injury in mice, minipigs, and nonhuman primates. This mini-review focuses on the role of IL-18 in response to gamma radiation-induced injury.

Circulating IL-18 Binding Protein (IL-18BP) and IL-18 as Dual Biomarkers of Total-Body Irradiation in Mice

We have previously reported that circulating interleukin-18 (IL-18) can be used as a radiation biomarker in mice, minipigs and nonhuman primates. In this study, we further determined the serum levels of IL-18 binding protein (IL-18BP), a natural endogenous antagonist of IL-18, in CD2F1 mice 1-13 days after total-body gamma irradiation (TBI) with different doses (5-10 Gy). We compared the changes in blood lymphocyte, neutrophil and platelet counts as well as the activation of the proapoptotic executioner caspase-3 and caspase-7, and the expression of the inflammatory factor cyclooxygenase 2 (COX-2) in spleen cells, with the changes of IL-18BP and IL-18 in mouse serum. We also evaluated the significance, sensitivity and specificity of alterations in radiation-induced IL-18BP. IL-18 increased from day 1-13 after TBI in a dose-dependent manner that was paralleled with an increase in IL-18 receptor alpha (IL-18Rα) in irradiated mouse spleen cells. IL-18BP rapidly increased (25-63 fold) in mouse serum on day 1 after different doses of TBI. However, it returned to baseline within 3 days after 5-7 Gy doses and within 7 days after 8 Gy dose, and was unaltered thereafter. In contrast, high doses of radiation (9 and 10 Gy) significantly sustained a higher level of IL-18BP in mouse serum and later induced a second phase of increase in IL-18BP on day 9-13 after irradiation, which coincided with the onset of animal mortality. Consistent with this observation, highly activated caspase-3 and -7 in 8-10 Gy irradiated mouse spleen cells exhibited reduced or no activity 24 h after 5 Gy, although radiation induced an inflammatory response, as shown by COX-2 expression in all irradiated cells. Our data suggest that the radiation-induced differential elevation of IL-18 and IL-18BP in animal serum is a dynamic and discriminative indicator of the severity of injury after exposure to ionizing radiation. These findings support the inclusion of the dual biomarkers IL-18BP and IL-18 in the development of a multifactorial strategy for radiation dose and injury assessment.

Links between innate immunity and normal tissue radiobiology

The body senses "danger" from "damaged self" molecules through members of the same receptor superfamily it uses for microbial "non-self", triggering canonical signaling pathways that lead to the generation of acute inflammatory responses. For this reason, the biology of normal tissue responses to moderate and clinically relevant doses of radiation is inextricably connected to innate immunity. The complex sequence of inflammatory events that ensues causes further cell and tissue damage to eliminate potential invaders but also leads to cytoprotective responses that limit the spread of damage and to wound healing through tissue regeneration or replacement. These sequential processes are orchestrated through multiple feedback control mechanisms involving cyclical production of free radicals and cytokines that are common to both radiation and immune signaling. This requires a concerted effort by resident tissue and inflammatory cell types, with macrophages apparently leading the way. The initial response to moderate doses of radiation therefore feeds into a pro-inflammatory paradigm whose eventual outcome is critically dependent upon the properties of the immune cells that are involved in tissue damage, regeneration and repair and that are in part under genetic influence. Importantly, these canonical pathways provide targets for interventions aimed at modifying normal tissue radiation responses. In this review, we examine areas of intersection between innate immunity and normal tissue radiobiology.

Mannose-6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R) in carcinogenesis

The cation-independent mannose-6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R) is a multifunctional receptor. It is involved in a variety of cellular processes which become dysregulated in cancer. Its tumor suppressor role was recognized a long time ago. However, due to its multifunctionality, it is not easy to understand the extent of its relevance to normal cellular physiology. Accordingly, it is even more difficult understanding its role in carcinogenesis. This review presents critical and focused highlights of data relating to M6P/IGF2R, obtained during more than 25 years of cancer research.