Spatial Transcriptomic Profiling of Tetraspanins in Stage 4 Colon Cancer from Primary Tumor and Liver Metastasis

Stage 4 colon cancer (CC) presents a significant global health challenge due to its poor prognosis and limited treatment options. Tetraspanins, the transmembrane proteins involved in crucial cancer processes, have recently gained attention as diagnostic markers and therapeutic targets. However, their spatial expression and potential roles in stage 4 CC tissues remain unknown. Using the GeoMx digital spatial profiler, we profiled all 33 human tetraspanin genes in 48 areas within stage 4 CC tissues, segmented into immune, fibroblast, and tumor compartments. Our results unveiled diverse gene expression patterns across different primary tumor sub-regions. CD53 exhibited distinct overexpression in the immune compartment, hinting at a potential role in immune modulation. TSPAN9 was specifically overexpressed in the fibroblast compartment, suggesting involvement in tumor invasion and metastasis. CD9, CD151, TSPAN1, TSPAN3, TSPAN8, and TSPAN13 displayed specific overexpression in the tumor compartment, indicating potential roles in tumor growth. Furthermore, our differential analysis revealed significant spatial changes in tetraspanin expression between patient-matched stage 4 primary CC and metastatic liver tissues. These findings provide spatially resolved insights into the expression and potential roles of tetraspanins in stage 4 CC progression, proposing their utility as diagnostic markers and therapeutic targets. Understanding this landscape is beneficial for tailoring therapeutic strategies to specific sub-tumor regions in the context of stage 4 CC and liver metastasis.

Exploring extracellular matrix and prostaglandin pathway alterations across varying resection margin distances of right-sided colonic adenocarcinoma

BACKGROUND

Surgical resection followed by indicated adjuvant therapy offers potential curative treatment in colonic adenocarcinoma. Beyond the well-established seed and soil theory of colon cancer progression, the 'normal-appearing' tissues near the tumor are not genuinely normal and remain as remnants in patients following surgery. Our objective was to elucidate the alteration of gene expression and pathways across various distances of resection margins in right-sided colonic adenocarcinoma.

METHODS

Twenty-seven fresh samples of primary cancer and 56 matched non-tumor tissues adjacent to the tumor (NAT) were collected from patients with resectable right-sided colon cancer. NAT were systematically obtained at varying distances (1, 5, and 10 cm) on both proximal and distal sides. Comprehensive gene expression analysis was performed using 770-gene PanCancer Progression Panel, delineating distinctive pathways and functional predictions for each region.

RESULTS

Distinctive gene signatures and pathways exhibited by normal-appearing tissues were discovered at varying distances from cancer. Notably, SFRP2, PTGDS, COL1A1, IL1B, THBS2, PTGIS, COL1A2, NPR1, and BGN were upregulated, while ENPEP, MMP1, and NRCAM were downregulated significantly in 1-cm tissue compared to farther distances. Substantial alterations in the extracellular matrix (ECM) and prostaglandin/thromboxane synthesis were significantly evident at the 1-cm distance. Functional analysis indicated enhanced cell viability and survival, alongside reduced cellular death and apoptosis.

CONCLUSIONS

Different distances exerted a significant impact on gene alteration within the normal-looking mucosa surrounding primary cancer, influenced by various mechanisms. These findings may highlight potential therapeutic targets related to the ECM and prostaglandin/thromboxane pathways for treatment strategies.

Aerosol protection using modified N95 respirator during upper gastrointestinal endoscopy: a randomized controlled trial

Background/Aims

The coronavirus disease 2019 pandemic has affected the worldwide practice of upper gastrointestinal endoscopy. Here we designed a modified N95 respirator with a channel for endoscope insertion and evaluated its efficacy in upper gastrointestinal endoscopy.

Methods

Thirty patients scheduled for upper gastrointestinal endoscopy were randomized into the modified N95 (n=15) or control (n=15) group. The mask was placed on the patient after anesthesia administration and particles were counted every minute before (baseline) and during the procedure by a TSI AeroTrak particle counter (9306-04; TSI Inc.) and categorized by size (0.3, 0.5, 1, 3, 5, and 10 µm). Differences in particle counts between time points were recorded.

Results

During the procedure, the modified N95 group displayed significantly smaller overall particle sizes than the control group (median [interquartile range], 231 [54-385] vs. 579 [213-1,379]×103/m3; p=0.056). However, the intervention group had a significant decrease in 0.3-µm particles (68 [-25-185] vs. 242 [72-588]×103/m3; p=0.045). No adverse events occurred in either group. The device did not cause any inconvenience to the endoscopists or patients.

Conclusions

This modified N95 respirator reduced the number of particles, especially 0.3-µm particles, generated during upper gastrointestinal endoscopy.

Abstract 2241: Transcriptomic analysis of tetraspanins in colorectal cancer

Introduction: Transmembrane proteins and their overexpression have been highly involved in malignancies. In particular, Tetraspanins (TSPANs)—a family of four-span transmembrane proteins—have been proposed as “master organizers” of multi-molecular membrane complexes by associating with specific partners and thus contributed to the progression of many cancer types. To date, transcriptomic analysis of all human TSPANs in colorectal cancer (CRC) has remained unclear. Here, we focused on utilizing next-generation RNA sequencing (RNA-Seq) to explore the expression level of TSPANs in primary tumor tissues of CRC, which is a complex disease and the second cause of cancer mortality worldwide.

Experimental Procedures: Resected primary tumor tissues of CRC were collected from 100 patients along with the written informed consents. Later, total RNA was extracted from all frozen patient tissues. RNA-Seq of those RNA samples was next done before the transcriptomic analysis of TSPANs in CRC was performed. Immunofluorescence (IF) and Immunohistochemistry (IHC) stains were also employed to confirm the target protein expression in formalin-fixed paraffin-embedded tissue (FFPE) slides from CRC patients.

Results: As a result of transcriptomic analysis of TSPANs in CRC tissues, among 33 human TSPANs, the high expression levels (transcript per million above the average of all TSPANs) of TSPAN1, TSPAN8, TSPAN24, TSPAN29 and TSPAN30 were observed in the patient-derived CRC tissues. Notably, the expression level of TSPAN8 was comparable with that of EPCAM, which is a well-known tumor marker. Moreover, the high expression of TSPAN8 protein could be clearly observed in both IF and IHC-stained FFPE slides from CRC patients. Our result highlights the possible relevance of these overexpressed TSPANs in CRC development.

Conclusions: This study is the first RNA-Seq-based transcriptomic analysis of all human TSPANs in CRC. Our finding suggests the significant overexpression of particular TSPANs, especially TSPAN8, in CRC. Further analyses will be beneficial for translational research in CRC. The overexpression of TSPANs may suggest a framework to further explore diagnostic, prognostic, and predictive surface biomarkers, therapeutic targets, and other applications for CRC.

Citation Format: Thanawat Suwatthanarak, Pariyada Tanjak, Amphun Chaiboonchoe, Onchira Acharayothin, Kullanist Thanormjit, Tharathorn Suwatthanarak, Watsaphon Tangkullayanone, Manop Pithukpakorn, Vitoon Chinswangwatanakul. Transcriptomic analysis of tetraspanins in colorectal cancer [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 2241.

Changes in Physical Components after Gastrectomy for Adenocarcinoma of Stomach and Esophagogastric Junction

Objective: Enhanced Recovery After Surgery (ERAS) is a multidisciplinary approach that aims to optimize perioperative management, promote postoperative recovery, reduce postoperative complications, and improve long-term survival. The current study aimed to evaluate and compare the postoperative physical activity after gastrectomy between patients who underwent upper gastrointestinal surgery according to ERAS and those who underwent surgery based on the conventional care (CC) protocol. Materials and Methods: This prospective and retrospective review enrolled 60 patients (n = 31, ERAS group; n = 29, CC protocol group) diagnosed with adenocarcinoma of the stomach and esophagogastric junction who underwent curative surgical resection. Physical outcomes, including body weight, body mass index, body fat percentage, basal metabolic rate, muscle mass, gait speed, and handgrip strength at the preoperative and immediate postoperative periods and at 1, 3, and 6 months postoperatively, were comparedbetween the ERAS and CC protocol groups. Results: One month after surgery, the ERAS group had a lower percentage of body weight loss than the CC protocol group. There was no significant difference in terms of muscle mass loss between the two groups. The hand grip strength of the ERAS group increased after surgery. Further, at 1 month postoperatively, the gait speed of patients who underwent total gastrectomy in the ERAS group was significantly higher than that of patients in the CC protocol group. Conclusion: ERAS for gastrectomy was associated with a lower percentage of weight loss and a trend toward physical activity enhancement in the early postoperative period.

The KRAS-Mutant Consensus Molecular Subtype 3 Reveals an Immunosuppressive Tumor Microenvironment in Colorectal Cancer

Colorectal cancers (CRC) with KRAS mutations (KRAS^mut) are frequently included in consensus molecular subtype 3 (CMS3) with profound metabolic deregulation. We explored the transcriptomic impact of KRAS^mut, focusing on the tumor microenvironment (TME) and pathways beyond metabolic deregulation. The status of KRAS^mut in patients with CRC was investigated and overall survival (OS) was compared with wild-type KRAS (KRAS^wt). Next, we identified CMS, and further investigated differentially expressed genes (DEG) of KRAS^mut and distinctive pathways. Lastly, we used spatially resolved gene expression profiling to define the effect of KRAS^mut in the TME regions of CMS3-classified CRC tissues. CRC patients with KRAS^mut were mainly enriched in CMS3. Their specific enrichments of immune gene signatures in immunosuppressive TME were associated with worse OS. Activation of TGFβ signaling by KRAS^mut was related to reduced pro-inflammatory and cytokine gene signatures, leading to suppression of immune infiltration. Digital spatial profiling in TME regions of KRAS^mut CMS3-classified tissues suggested up-regulated genes, CD40, CTLA4, ARG1, STAT3, IDO, and CD274, that could be characteristic of immune suppression in TME. This study may help to depict the complex transcriptomic profile of KRAS^mut in immunosuppressive TME. Future studies and clinical trials in CRC patients with KRAS^mut should consider these transcriptional landscapes.

Is fascial closure required for a 12-mm trocar? A comparative study on trocar site hernia with long-term follow up

BACKGROUND

Despite the infrequency of trocar site hernias (TSHs), fascial closure continues to be recommended for their prevention when using a ≥ 10-mm trocar.

AIM

To identify the necessity of fascial closure for a 12-mm nonbladed trocar incision in minimally invasive colorectal surgeries.

METHODS

Between July 2010 and December 2018, all patients who underwent minimally invasive colorectal surgery at the Minimally Invasive Surgery Unit of Siriraj Hospital were retrospectively reviewed. All patients underwent cross-sectional imaging for TSH assessment. Clinicopathological characteristics were recorded. Incidence rates of TSH and postoperative results were analyzed.

RESULTS

Of the 254 patients included, 70 (111 ports) were in the fascial closure (closed) group and 184 (279 ports) were in the nonfascial closure (open) group. The median follow up duration was 43 mo. During follow up, three patients in the open group developed TSHs, whereas none in the closed group developed the condition (1.1% vs 0%, P = 0.561). All TSHs occurred in the right lower abdomen. Patients whose drains were placed through the same incision had higher rates of TSHs compared with those without the drain. The open group had a significantly shorter operative time and lower blood loss than the closed group.

CONCLUSION

Routine performance of fascial closure when using a 12-mm nonbladed trocar may not be needed. However, further prospective studies with cross-sectional imaging follow-up and larger sample size are needed to confirm this finding.

Surgical Outcomes of Bariatric Surgery in Siriraj Hospital for the First 100 Morbidly Obese Patients Treated

Objective: Bariatric surgery is considered the most effective treatment for morbid obesity, and is increasingly performed in Thailand and globally. We aimed to establish the outcomes of bariatric surgery performed at Siriraj Hospital, Bangkok. Materials and Methods: This was a retrospective study of patients who underwent bariatric surgery between January 2012 and June 2016. Results: The records of the first 100 patients who underwent bariatric surgery were reviewed, comprising 58 patients who underwent laparoscopic sleeve gastrectomy (LSG) and 42 patients who underwent laparoscopic Roux-en-Y gastric bypass (LRYGB). The median patient age, preoperative body weight, and BMI were 36 years old, 129 kg, and 46.3 kg/m2. All the procedures were performed by a laparoscopic approach. The median operative times for LSG and LRYGB were 156 [85-435] and 265 [180-435] minutes. The median hospital stay was 3 days [3-14]. The major complication rate was 4%. There was no mortality in the 30-day postoperative period. The mean %excess weight loss (%EWL) of LSG was 56.8 ± 19.8%, 59.9 ± 21.7%, and 55.1 ± 21.3%, at 1, 2, and 3 years after surgery. The mean %EWL of LRYGB was 67 ± 18.3%, 66.2 ± 21.4%, and 63.6 ± 19.9%, at 1, 2, and 3 years after surgery. In the patients with type-II diabetes mellitus, 67% had complete diabetic remission at 1 year. The median FBS dropped from 127 to 99 mg/dL (p < 0.001) and HbA1c from 6.6% to 5.5% (p < 0.001). The remission rates of hypertension and dyslipidemia were 58% and 73%. Conclusion: The bariatric procedures are safe with a low complication rate. The procedures also provide good outcomes in postoperative weight loss and comorbidity resolution.

Management of aerosol generation during upper gastrointestinal endoscopy

In the highly contagious coronavirus disease 2019 pandemic, aerosol-generating procedures (AGPs) are associated with high-risk of transmission. Upper gastrointestinal endoscopy is a procedure with the potential to cause dissemination of bodily fluids. At present, there is no consensus that endoscopy is defined as an AGP. This review discusses the current evidence on this topic with additional management. Prevailing publications on coronavirus related to upper gastrointestinal endoscopy and aerosolization from the PubMed and Scopus databases were searched and reviewed. Comparative quantitative analyses showed a significant elevation of particle numbers, implying that aerosols were generated by upper gastrointestinal endoscopy. The associated source events have also been reported. To reduce the dispersion, certain protective measures have been developed. Endoscopic unit protocols are recommended for the concerned personnel. Therefore, upper gastrointestinal endoscopy should be classified as an AGP. Proper practices should be adopted by healthcare workers and patients.

Outcomes of Laparoscopic Common Bile Duct Exploration by Chopstick Technique in Choledocholithiasis

Background and Objectives

Laparoscopic cholecystectomy with common bile duct exploration (LC with LCBDE) remains the preferred technique for difficult common bile duct stone (CBDS) removal. The chopstick method uses commonly available instruments and may be cost-saving compared to other techniques. We studied the outcome of LCBDE using the chopstick technique to determine if it could be considered a first-choice method.

Methods

Data from all patients that underwent LCBDE from January 1, 2012 to April 30, 2019 were retrospectively analyzed. A standard 4-port incision and CBDS permitted extraction with two laparoscopic instruments by chopstick technique via vertical choledochotomy. Demographic data, stone clearance rate, surgical outcomes, complications, and other associated factors were evaluated.

Results

Thirty-two patients underwent LCBDE. The mean number of preoperative endoscopic retrograde cholangiopancreatography (ERCP) sessions was 2.4. In 65.5% of cases, the CBDS was completely removed by the chopstick technique, while 96.9% of stones were removed after using additional tools. The need for additional instruments was associated with increased age, increased numbers of stones, longer period from the latest ERCP session, and previous upper abdominal surgery. The conversion rate to open surgery was 28.1% and was significantly associated with a history of upper abdominal surgery.

Conclusion

The chopstick technique is a good alternative and could be considered as a first-line technique in LCBDE to remove the CBDS in cases with 1 to 2 large suprapancreatic CBDS due to instrument availability, cost-effectiveness, and comparable surgical outcomes.