Stable Dual miR-143 and miR-506 Upregulation Inhibits Proliferation and Cell Cycle Progression

The mainstays of lung cancer pathogenesis are cell cycle progression dysregulation, impaired apoptosis, and unregulated cell proliferation. While individual microRNA (miR) targeting or delivering is a promising approach that has been extensively studied, combination of miR targeting can enhance therapeutic efficacy and overcome limitations present in individual miR regulations. We previously reported on the use of a miR-143 and miR-506 combination via transient transfections against lung cancer. In this study, we evaluated the effect of miR-143 and miR-506 under stable deregulations in A549 lung cancer cells. We used lentiviral transductions to either up- or downregulate the two miRs individually or in combination. The cells were sorted and analyzed for miR deregulation via qPCR. We determined the miR deregulations' effects on the cell cycle, cell proliferation, cancer cell morphology, and cell motility. Compared to the individual miR deregulations, the combined miR upregulation demonstrated a miR-expression-dependent G2 cell cycle arrest and a significant increase in the cell doubling time, whereas the miR-143/506 dual downregulation demonstrated increased cellular motility. Furthermore, the individual miR-143 and miR-506 up- and downregulations exhibited cellular responses lacking an apparent miR-expression-dependent response in the respective analyses. Our work here indicates that, unlike the individual miR upregulations, the combinatorial miR treatment remained advantageous, even under prolonged miR upregulation. Finally, our findings demonstrate potential advantages of miR combinations vs. individual miR treatments.

Abstract 3759: Impact of individual and combined deregulation of miR-143 and miR-506 on cytokinetic and morphometric parameters in A549 lung cancer cells

Lung cancer (LC) is among the leading causes of death from malignancies worldwide. miRNAs (miRs), small noncoding RNAs capable of regulating gene expression through the cell’s RNAi mechanism, have emerged as promising molecules for cancer treatment. In our previous work, we identified two miRs, miR-143 and miR-506, whose transient transfection induced apoptosis, cell cycle inhibition, and cyclin-dependent kinase (CDK) 1, 4, and 6 downregulations. Here, we developed stable deregulations of the miRs’ expressions in A549 cells, individually or in combination, to evaluate their effect on LC cell behavior. To establish homogeneous populations of deregulated cells, A549 cells with stable up and downregulated miR-143 and miR-506, alone or in combination, were sorted according to marker expression using fluorescence-activated cell sorting (FACS). miR deregulations were confirmed with quantitative real-time polymerase chain reaction (qRT -PCR) analysis, and the cells were analyzed for changes in cell proliferation through cell cycle analysis using flow cytometry and cell doubling time using Quantitative Phase Imaging (QPI). With the same method, morphometric characteristics were quantified. Finally, we evaluated the motility of the cells using a scratch assay and determined the gene expression of CDKs. Taqman qPCR analysis indicated a >5-fold increase of the respective miR’s basal expression due to the stable transfections. The cell cycle analysis indicated a complex behavior for the individual miRs, while, in contrast, the combined upregulation of the two miRs indicated a G2 inhibition, representing a well-defined behavior in comparison to both the control and downregulation groups. Furthermore, the combined miR upregulation increased the cell doubling time compared to the control and respective downregulations. Similarly, using QPI microscopy, we observed that the miR combination upregulation had higher cellular sphericity, perimeter, and area compared to the control group. The wound healing assay did not indicate statistically significant differences among the different groups, with miR-506 upregulation demonstrating the slowest closure rate, followed by miR -143. In contrast, the differences between the miR-combination and control group were small, although the anti-miR-combination indicated an accelerated closure. In conclusion, the combined upregulation of both miRs inhibited cell proliferation through a G2 arrest, while the deregulation of the individual miRs demonstrated a complex behavior. Thus, the miR-combination’s consistent, promising behavior would indicate potential benefits using the two miRs against LC that merits further evaluation.

Citation Format: Archana Shrestha, Behnaz Lahooti, Mahboubeh Madadi, Constantinos M. Mikelis, George Mattheolabakis. Impact of individual and combined deregulation of miR-143 and miR-506 on cytokinetic and morphometric parameters in A549 lung cancer cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3759.

Endothelial-Specific Targeting of RhoA Signaling via CD31 Antibody-Conjugated Nanoparticles

Existing vascular endothelial growth factor-oriented antiangiogenic approaches are known for their high potency. However, significant side effects associated with their use drive the need for novel antiangiogenic strategies. The small GTPase RhoA is an established regulator of actin cytoskeletal dynamics. Previous studies have highlighted the impact of endothelial RhoA pathway on angiogenesis. Rho-associate kinase (ROCK), a direct RhoA effector, is potently inhibited by Fasudil, a clinically relevant ROCK inhibitor. Here, we aimed to target the RhoA signaling in endothelial cells by generating Fasudil-encapsulated CD31-targeting liposomes as a potential antiangiogenic therapy. The liposomes presented desirable characteristics, preferential binding to CD31-expressing HEK293T cells and to endothelial cells, inhibited stress fiber formation and cytoskeletal-related morphometric parameters, and inhibited in vitro angiogenic functions. Overall, this work shows that the nanodelivery-mediated endothelial targeting of RhoA signaling can offer a promising strategy for angiogenesis inhibition in vascular-related diseases. SIGNIFICANCE STATEMENT: Systemic administration of antiangiogenic therapeutics induces side effects to non-targeted tissues. This study, among others, has shown the impact of the RhoA signaling in the endothelial cells and their angiogenic functions. Here, to minimize potential toxicity, this study generated CD31-targeting liposomes with encapsulated Fasudil, a clinically relevant Rho kinase inhibitor, and successfully targeted endothelial cells. In this proof-of-principle study, the efficient Fasudil delivery, its impact on the endothelial signaling, morphometric alterations, and angiogenic functions verify the benefits of site-targeted antiangiogenic therapy.

Longitudinal optical imaging technique to visualize progressive axonal damage after brain injury in mice reveals responses to different minocycline treatments

A high-resolution, three-dimensional, optical imaging technique for the murine brain was developed to identify the effects of different therapeutic windows for preclinical brain research. This technique tracks the same cells over several weeks. We conducted a pilot study of a promising drug to treat diffuse axonal injury (DAI) caused by traumatic brain injury, using two different therapeutic windows, as a means to demonstrate the utility of this novel longitudinal imaging technique. DAI causes immediate, sporadic axon damage followed by progressive secondary axon damage. We administered minocycline for three days commencing one hour after injury in one treatment group and beginning 72 hours after injury in another group to demonstrate the method’s ability to show how and when the therapeutic drug exerts protective and/or healing effects. Fewer varicosities developed in acutely treated mice while more varicosities resolved in mice with delayed treatment. For both treatments, the drug arrested development of new axonal damage by 30 days. In addition to evaluation of therapeutics for traumatic brain injury, this hybrid microlens imaging method should be useful to study other types of brain injury and neurodegeneration and cellular responses to treatment.

Analyzing factors associated with women's attitudes and behaviors toward screening mammography using design-based logistic regression

We examined the factors associated with screening mammography adherence behaviors and influencing factors on women's attitudes toward mammography in non-adherent women. Design-based logistic regression models were developed to characterize the influencing factors, including socio-demographic, health related, behavioral characteristics, and knowledge of breast cancer/mammography, on women's compliance with and attitudes toward mammography using the 2003 Health Information National Trends Survey data. Findings indicate significant associations among adherence to mammography and marital status, income, health coverage, being advised by a doctor to have a mammogram, having had Pap smear before, perception of chance of getting breast cancer, and knowledge of mammography (frequency of doing mammogram) in both women younger than 65 and women aged 65 and older. However, number of visits to a healthcare provider per year and lifetime number of smoked cigarettes are only significant for women younger than 65. Factors significantly associated with attitudes toward mammography in non-adherent women are age, being advised by a doctor to have a mammogram, and seeking cancer information. To enhance adherence to mammography programs, physicians need to continue to advise their patients to obtain mammograms. In addition, increasing women's knowledge about the frequency and starting age for screening mammography may improve women's adherence. Financially related factors such as income and insurance are also shown to be significant factors. Hence, healthcare policies aimed at providing breast cancer screening services to underserved women will likely enhance mammography participation.