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Open Access Publications from the University of California

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This series is automatically populated with publications deposited by UC San Diego School of Medicine Department of Surgery researchers in accordance with the University of California’s open access policies. For more information see Open Access Policy Deposits and the UC Publication Management System.

Cover page of Computational Analysis Suggests That AsnGTT 3-tRNA-Derived Fragments Are Potential Biomarkers in Papillary Thyroid Carcinoma.

Computational Analysis Suggests That AsnGTT 3-tRNA-Derived Fragments Are Potential Biomarkers in Papillary Thyroid Carcinoma.

(2024)

Transfer-RNA-derived fragments (tRFs) are a novel class of small non-coding RNAs that have been implicated in oncogenesis. tRFs may act as post-transcriptional regulators by recruiting AGO proteins and binding to highly complementary regions of mRNA at seed regions, resulting in the knockdown of the transcript. Therefore, tRFs may be critical to tumorigenesis and warrant investigation as potential biomarkers. Meanwhile, the incidence of papillary thyroid carcinoma (PTC) has increased in recent decades and current diagnostic technology stands to benefit from new detection methods. Although small non-coding RNAs have been studied for their role in oncogenesis, there is currently no standard for their use as PTC biomarkers, and tRFs are especially underexplored. Accordingly, we aim to identify dysregulated tRFs in PTC that may serve as biomarker candidates. We identified dysregulated tRFs and driver genes between PTC primary tumor samples (n = 511) and adjacent normal tissue samples (n = 59). Expression data were obtained from MINTbase v2.0 and The Cancer Genome Atlas. Dysregulated tRFs and genes were analyzed in tandem to find pairs with anticorrelated expression. Significantly anticorrelated tRF-gene pairs were then tested for potential binding affinity using RNA22-if a heteroduplex can form via complementary binding, this would support the hypothesized RNA silencing mechanism. Four tRFs were significantly dysregulated in PTC tissue (p < 0.05), with only AsnGTT 3-tRF being upregulated. Binding affinity analysis revealed that tRF-30-RY73W0K5KKOV (AsnGTT 3-tRF) exhibits sufficient complementarity to potentially bind to and regulate transcripts of SLC26A4, SLC5A8, DIO2, and TPO, which were all found to be downregulated in PTC tissue. In the present study, we identified dysregulated tRFs in PTC and found that AsnGTT 3-tRF is a potential post-transcriptional regulator and biomarker.

Cover page of Association of Depression and Antidepressant Use With Driving Behaviors in Older Adults: A LongROAD Study.

Association of Depression and Antidepressant Use With Driving Behaviors in Older Adults: A LongROAD Study.

(2024)

Older adults aged 70 and older who drive have higher crash death rates per mile driven compared to middle aged (35-54 years) adults who drive in the US. Prior studies have found that depression and or antidepressant medication use in older adults are associated with an increase in the vehicular crash rate. Using data from the prospective multi-site AAA Longitudinal Research on Aging Drivers Study, this analysis examined the independent and interdependent associations of self-reported depression and antidepressant use with driving behaviors that can increase motor vehicle crash risk such as hard braking, speeding, and night-time driving in adults over age 65. Of the 2951 participants, 6.4% reported having depression and 21.9% were on an antidepressant medication. Correcting for age, race, gender, and education level, participants on an antidepressant had increased hard braking events (1.22 [1.10-1.34]) but self-reported depression alone was not associated with changes in driving behaviors.

Cover page of Accurate Co-Localization of Luciferase Expression and Fluorescent Anti-CEA Antibody Targeting of Liver Metastases in an Orthotopic Mouse Model of Colon Cancer.

Accurate Co-Localization of Luciferase Expression and Fluorescent Anti-CEA Antibody Targeting of Liver Metastases in an Orthotopic Mouse Model of Colon Cancer.

(2024)

BACKGROUND: The present study aimed to validate the accuracy of a tumor-specific antibody to target liver metastases of colorectal cancer. METHODS: A humanized anti-CEA antibody conjugated to a fluorescent dye (M5A-IR800) was tested for targeting human colorectal cancer liver metastases (CRLMs) expressing luciferase in an orthotopic mouse model. Orthotopic mouse models of CRLMs were established by implanting fragments of a luciferase-expressing human colorectal cancer cell line, LS174T, in the liver of nude mice. Mice received 50 µg M5A-IR800 72 h prior to imaging. To test co-localization, bioluminescence imaging was performed using D-luciferin, which was given via intraperitoneal injection just prior to imaging. RESULTS: Tumors were able to be visualized non-invasively through the skin with the luciferase-luciferin signal. Intra-abdominal imaging showed accurate labeling of CRLMs with M5A-IR800, which co-localized with the luciferase-luciferin signal. CONCLUSIONS: The present results validate the accuracy of a tumor-specific anti-CEA antibody in targeting liver metastases of colorectal cancer.

Cover page of The Long Haul to Surgery: Long COVID Has Minimal Burden on Surgical Departments.

The Long Haul to Surgery: Long COVID Has Minimal Burden on Surgical Departments.

(2024)

Many patients infected with the SARS-CoV-2 virus (COVID-19) continue to experience symptoms for weeks to years as sequelae of the initial infection, referred to as Long COVID. Although many studies have described the incidence and symptomatology of Long COVID, there are little data reporting the potential burden of Long COVID on surgical departments. A previously constructed database of survey respondents who tested positive for COVID-19 was queried, identifying patients reporting experiencing symptoms consistent with Long COVID. Additional chart review determined whether respondents had a surgical or non-routine invasive procedure on or following the date of survey completion. Outcomes from surgeries on patients reporting Long COVID symptoms were compared to those from asymptomatic patients. A total of 17.4% of respondents had surgery or a non-routine invasive procedure in the study period. A total of 48.8% of these patients reported experiencing symptoms consistent with Long COVID. No statistically significant differences in surgical outcomes were found between groups. The results of this analysis demonstrate that Long COVID does not appear to have created a significant burden of surgical disease processes on the healthcare system despite the wide range of chronic symptoms and increased healthcare utilization by this population. This knowledge can help guide surgical operational resource allocation as a result of the pandemic and its longer-term sequelae.

Cover page of Percutaneous auricular neuromodulation (nerve stimulation) for the treatment of pain following cholecystectomy and hernia repair: a randomized, double-masked, sham-controlled pilot study.

Percutaneous auricular neuromodulation (nerve stimulation) for the treatment of pain following cholecystectomy and hernia repair: a randomized, double-masked, sham-controlled pilot study.

(2024)

BACKGROUND: Percutaneous auricular nerve stimulation (neuromodulation) involves implanting electrodes around the ear and administering an electric current. A device is currently available within the USA cleared to treat symptoms from opioid withdrawal, and multiple reports suggest a possible postoperative analgesic effect. The current randomized controlled pilot study was undertaken to (1) determine the feasibility and optimize the protocol for a subsequent definitive clinical trial; and (2) estimate the treatment effect of auricular neuromodulation on postoperative pain and opioid consumption following two ambulatory surgical procedures. METHODS: Within the recovery room following cholecystectomy or hernia repair, an auricular neuromodulation device (NSS-2 Bridge, Masimo, Irvine, California, USA) was applied. Participants were randomized to 5 days of either electrical stimulation or sham in a double-blinded fashion. RESULTS: In the first 5 days, the median (IQR) pain level for active stimulation (n=15) was 0.6 (0.3-2.4) vs 2.6 (1.1-3.7) for the sham group (n=15) (p=0.041). Concurrently, the median oxycodone use for the active stimulation group was 0 mg (0-1), compared with 0 mg (0-3) for the sham group (p=0.524). Regarding the highest pain level experienced over the entire 8-day study period, only one participant (7%) who received active stimulation experienced severe pain, versus seven (47%) in those given sham (p=0.031). CONCLUSIONS: Percutaneous auricular neuromodulation reduced pain scores but not opioid requirements during the initial week after cholecystectomy and hernia repair. Given the ease of application as well as a lack of systemic side effects and reported complications, a definitive clinical trial appears warranted. TRIAL REGISTRATION NUMBER: NCT05521516.

Cover page of Targeting Patient-Derived Orthotopic Gastric Cancers with a Fluorescent Humanized Anti-CEA Antibody

Targeting Patient-Derived Orthotopic Gastric Cancers with a Fluorescent Humanized Anti-CEA Antibody

(2024)

Background

Gastric cancer poses a major diagnostic and therapeutic challenge as surgical resection provides the only opportunity for a cure. Specific labeling of gastric cancer could distinguish resectable and nonresectable disease and facilitate an R0 resection, which could improve survival.

Methods

Two patient-derived gastric cancer lines, KG8 and KG10, were established from surgical specimens of two patients who underwent gastrectomy for gastric adenocarcinoma. Harvested tumor fragments were implanted into the greater curvature of the stomach to establish patient-derived orthotopic xenograft (PDOX) models. M5A (humanized anti-CEA antibody) or IgG control antibodies were conjugated with the near-infrared dye IRDye800CW. Mice received 50 µg of M5A-IR800 or 50 µg of IgG-IR800 intravenously and were imaged after 72 hr. Fluorescence imaging was performed by using the LI-COR Pearl Imaging System. A tumor-to-background ratio (TBR) was calculated by dividing the mean fluorescence intensity of the tumor versus adjacent stomach tissue.

Results

M5A-IR800 administration resulted in bright labeling of both KG8 and K10 tumors. In the KG8 PDOX models, the TBR for M5A-IR800 was 5.85 (SE ± 1.64) compared with IgG-IR800 at 0.70 (SE ± 0.17). The K10 PDOX models had a TBR of 3.71 (SE ± 0.73) for M5A-IR800 compared with 0.66 (SE ± 0.12) for IgG-IR800.

Conclusions

Humanized anti-CEA (M5A) antibodies conjugated to fluorescent dyes provide bright and specific labeling of gastric cancer PDOX models. This tumor-specific fluorescent antibody is a promising potential clinical tool to detect the extent of disease for the determination of resectability as well as to visualize tumor margins during gastric cancer resection.

Cover page of The Mutational and Microenvironmental Landscape of Cutaneous Squamous Cell Carcinoma: A Review.

The Mutational and Microenvironmental Landscape of Cutaneous Squamous Cell Carcinoma: A Review.

(2024)

Cutaneous squamous cell carcinoma (cSCC) manifests through the complex interactions of UV-induced DNA damage, genetic mutations, and alterations in the tumor microenvironment. A high mutational burden is present in cSCC, as well as both cSCC precursors and normal skin, making driver genes difficult to differentiate. Despite this, several key driver genes have been identified, including TP53, the NOTCH family, CDKN2A, PIK3CA, and EGFR. In addition to mutations, the tumor microenvironment and the manipulation and evasion of the immune system play a critical role in cSCC progression. Novel therapeutic approaches, such as immunotherapy and EGFR inhibitors, have been used to target these dysregulations, and have shown promise in treating advanced cSCC cases, emphasizing the need for targeted interventions considering both genetic and microenvironmental factors for improved patient outcomes.

INF2-mediated actin polymerization at ER-organelle contacts regulates organelle size and movement.

(2024)

Proper regulation of organelle dynamics and inter-organelle contacts is critical for cellular health and function. Both the endoplasmic reticulum (ER) and actin cytoskeleton are known to regulate organelle dynamics, but how, when, and where these two subcellular components are coordinated to control organelle dynamics remains unclear. Here, we show that ER-associated actin consistently marks mitochondrial, endosomal, and lysosomal fission sites. We also show that actin polymerization by the ER-anchored isoform of the formin protein INF2 is a key regulator of the morphology and mobility of these organelles. Together, our findings establish a mechanism by which INF2-mediated polymerization of ER-associated actin at ER-organelle contacts regulates organelle dynamics.