Germline mutations of homologous recombination genes and clinical outcomes in pancreatic cancer: a multicenter study in Taiwan.

BACKGROUND: Cancer susceptibility germline mutations are associated with pancreatic ductal adenocarcinoma (PDAC). However, the hereditary status of PDAC and its impact on survival is largely unknown in the Asian population. METHODS: Exome sequencing was performed on 527 blood samples from PDAC individuals and analyzed for mutations in 80 oncogenic genes. Pathogenic and likely pathogenic (P/LP) germline variants were diagnosed according to the ACMG variant classification categories. The association between germline homologous recombination gene mutations (gHRmut, including BAP1, BRCA1, BRCA2, PALB2, ATM, BLM, BRIP1, CHEK2, NBN, MUTYH, FANCA and FANCC) and the treatment outcomes was explored in patients with stage III/IV diseases treated with first-line (1L) platinum-based versus platinum-free chemotherapy. RESULTS: Overall, 104 of 527 (19.7%) patients carried germline P/LP variants. The most common mutated genes were BRCA2 (3.60%), followed by ATR (2.66%) and ATM (1.9%). After a median follow-up duration of 38.3-months (95% confidence interval, 95% CI 35.0-43.7), the median overall survival (OS) was not significantly different among patients with gHRmut, non-HR germline mutations, or no mutation (P = 0.43). Among the 320 patients with stage III/IV disease who received 1L combination chemotherapy, 32 (10%) had gHRmut. Of them, patients receiving 1L platinum-based chemotherapy exhibited a significantly longer median OS compared to those with platinum-free chemotherapy, 26.1 months (95% CI 12.7-33.7) versus 9.6 months (95% CI 5.9-17.6), P = 0.001. However, the median OS of patients without gHRmut was 14.5 months (95% CI 13.2-16.9) and 12.6 months (95% CI 10.8-14.7) for patients receiving 1L platinum-based and platinum-free chemotherapy, respectively (P = 0.22). These results were consistent after adjusting for potential confounding factors including age, tumor stage, performance status, and baseline CA 19.9 in the multivariate Cox regression analysis. CONCLUSIONS: Our study showed that nearly 20% of Taiwanese PDAC patients carried germline P/LP variants. The longer survival observed in gHRmut patients treated with 1L platinum-based chemotherapy highlights the importance of germline testing for all patients with advanced PDAC at diagnosis.

The emergence of RAS mutations in patients with RAS wild-type mCRC receiving cetuximab as first-line treatment: a noninterventional, uncontrolled multicenter study.

ABSRTACT: BACKGROUND: Patients treated with anti-epidermal growth factor receptor (anti-EGFR) will ultimately develop acquired resistance promoted by clonal selection, mainly the emergence of mutations in the MAPK pathway (mostly RAS mutations). Baseline assessment of RAS mutations in the blood of patients correlates well with RAS tumour tissue testing and is currently an alternative option in routine clinical practice to guide first-line therapy. The aim of this study was the prevalence of acquired genomic alterations detected in the auxiliary tool of ctDNA testing and investigated the role of RAS ctDNA status for detecting tumour response and predicting benefit to anti-EGFR therapy. METHODS: Only patients with concordant wild-type formalin-fixed, paraffin-embedded (FFPE) tumour tissue and baseline ctDNA RAS wild-type were included. RAS mutations in plasma were evaluated using MassARRAY platform. Blood samples were collected at baseline, every 3 months during first-line treatment, and at disease progression. The primary endpoint was the detection rate of RAS mutations during cetuximab treatment. The correlation between response and survival outcomes and the emergence of circulating RAS mutations was also analysed. RESULTS: The detection rate of RAS mutations during treatment was 9.3% (10/108). RAS mutations detection occurred a median of 3 months prior to radiologic documentation. The subgroup of patients with RAS mutations exhibited significantly inferior progression-free survival and overall survival (P = 0.002 and 0.027, respectively) but the baseline characteristics, response rates, disease control rates, and metastatectomy were not significant (all P > 0.05). CONCLUSIONS: We demonstrated that RAS ctDNA status might be a valuable biomarker for detecting early tumour response and predicting benefit to anti-EGFR therapy. CLINICAL TRIAL REGISTRATION: NCT03401957 (January 17, 2018).

Dual role of sprouty2 as an inhibitor of RAS/ERK-driven proliferation and a promoter of cancer invasion in KRAS wild-type colorectal cancer.

Sprouty2 (SPRY2) is known to inhibit the RAS/MAPK/ERK pathway, and is a potential study target for cancer. The effect of SPRY2 in colorectal cancer (CRC) and whether it is influenced by KRAS mutation are not known. We manipulated SPRY2 gene expression and used an activating KRAS-mutant plasmid to determine its effect on CRC cell function in vitro and/or in vivo. We performed SPRY2 immunohistochemical staining in 143 CRC specimens and analyzed the staining results with various clinicopathological characteristics in relation to KRAS mutation status. SPRY2 knockdown in Caco-2 cells carrying the wild-type (WT) KRAS gene upregulated phosphorylated ERK (p-ERK) levels and increased cell proliferation in vitro, but inhibited cell invasion. However, SPRY2 knockdown in SW480 cells (activating KRAS mutant) or Caco-2 cells transfected with KRAS-mutant plasmid did not significantly alter p-ERK levels, cell proliferation, or invasion. The xenografts of SPRY2-knockdown Caco-2 cells were larger with less deep muscle invasion than those of control cells. The clinical cohort study revealed a positive association of SPRY2 protein expression with pT status, lymphovascular invasion, and perineural invasion in KRAS-WT CRCs. However, the associations were not observed in KRAS-mutant CRCs. Interestingly, high SPRY2 expression was related to shorter cancer-specific survival in both KRAS-WT and KRAS-mutant CRC patients. Our study demonstrated the dual role of SPRY2 as an inhibitor of RAS/ERK-driven proliferation and as a promoter of cancer invasion in KRAS-WT CRC. SPRY2 may promote the invasion and progression of KRAS-WT CRC, and might also enhance KRAS-mutant CRC progression through pathways other than invasion.

CHK2 activation contributes to the development of oxaliplatin resistance in colorectal cancer.

BACKGROUND: Colorectal cancer (CRC), the most common cancer type, causes high morbidity and mortality. Patients who develop drug resistance to oxaliplatin-based regimens have short overall survival. Thus, identifying molecules involved in the development of oxaliplatin resistance is critical for designing therapeutic strategies. METHODS: A proteomic screen was performed to reveal altered protein kinase phosphorylation in oxaliplatin-resistant (OR) CRC tumour spheroids. The function of CHK2 was characterised using several biochemical techniques and evident using in vitro cell and in vivo tumour models. RESULTS: We revealed that the level of phospho-CHK2(Thr68) was elevated in OR CRC cells and in ~30% of tumour samples from patients with OR CRC. We demonstrated that oxaliplatin activated several phosphatidylinositol 3-kinase-related kinases (PIKKs) and CHK2 downstream effectors and enhanced CHK2/PARP1 interaction to facilitate DNA repair. A phosphorylation mimicking CHK2 mutant, CHK2T68D, but not a kinase-dead CHK2 mutant, CHK2D347A, promoted DNA repair, the CHK2/PARP1 interaction, and cell growth in the presence of oxaliplatin. Finally, we showed that a CHK2 inhibitor, BML-277, reduced protein poly(ADP-ribosyl)ation (PARylation), FANCD2 monoubiquitination, homologous recombination and OR CRC cell growth in vitro and in vivo. CONCLUSION: Our findings suggest that CHK2 activity is critical for modulating oxaliplatin response and that CHK2 is a potential therapeutic target for OR CRC.

PD-L1 Expression in High-Risk Early-Stage Colorectal Cancer-Its Clinical and Biological Significance in Immune Microenvironment.

Programmed death-ligand 1 (PD-L1) is an immune checkpoint molecule that can regulate immune responses in the tumor microenvironment (TME); however, the clinical applications of PD-L1 in early-stage colorectal cancer (CRC) remain unclear. In this study, we aimed to investigate the relationship between PD-L1 expression and survival outcome and explore its relevant immune responses in CRC. PD-L1 expression was evaluated by immunohistochemical staining to determine the tumor proportion score and combined positive score (CPS) in a Taiwanese CRC cohort. The oncomine immune response research assay was conducted for immune gene expression analyses. CRC datasets from the TCGA database were reappraised for PD-L1-associated gene enrichment analyses using GSEA. The high expression of PD-L1 (CPS ≥ 5) was associated with longer recurrence-free survival (p = 0.031) and was an independent prognostic factor as revealed by multivariate analysis. High PD-L1 expression was related to six immune-related gene signatures, and CXCL9 is the most significant overexpressed gene in differential analyses. High CXCL9 expression correlated with increased infiltration levels of immune cells in the TME, including CD8+ T lymphocytes and M1 macrophages. These findings suggest that high PD-L1 expression is a prognostic factor of early-stage CRC, and CXCL9 may play a key role in regulating PD-L1 expression.

O6-methylguanine-DNA methyltransferase modulates cisplatin-induced DNA double-strand breaks by targeting the homologous recombination pathway in nasopharyngeal carcinoma.

BACKGROUND: The homologous recombination (HR) pathway is involved in DNA damage response (DDR), which is crucial to cancer cell survival after treatment with DNA damage agents. O6-methylguanine DNA methyltransferase (MGMT) is associated with cisplatin (CDDP) resistance in cancer cells; however, the underlying mechanisms remain unclear. Here, we explored the interactions between MGMT and the HR pathway in CDDP-activated DDR and their clinical implications in nasopharyngeal carcinoma (NPC). METHODS: Human NPC cells were assessed using loss-of-function approaches in vitro. The expression correlations between MGMT and major proteins of the HR pathway were analyzed through Western blotting, quantitative real-time PCR, and bioinformatic analysis by using a public database. The physical interactions between MGMT and HR proteins were studied using co-immunoprecipitation and immunofluorescence analyses. Cell comet tails and γ-H2AX expression levels were examined to evaluate double-strand break (DSB) formation. Established immunofluorescence and reporter analyses were conducted to measure HR activity. Xenograft and cell viability studies were used to assess the therapeutic potential of MGMT inhibition in combination with CDDP and poly(ADP-ribose) polymerase (PARP) inhibitor, respectively. RESULTS: Among major proteins of the HR pathway, MGMT suppression inhibited CDDP-induced RAD51 expression. Bioinformatic analyses showed a positive correlation between MGMT and RAD51 expression in patients with NPC. Moreover, MGMT physically interacted with BRCA1 and regulated CDDP-induced BRCA1 phosphorylation (ser 988). In functional assays, MGMT inhibition increased CDDP-induced DSB formation through attenuation of HR activity. NPC xenograft studies demonstrated that MGMT inhibition combined with CDDP treatment reduced tumor size and downregulated RAD51 expression and BRCA1 phosphorylation. Furthermore, MGMT suppression increased PARP inhibitor-induced cell death and DSB formation in NPC cells. CONCLUSION: MGMT is crucial in the activation of the HR pathway and regulates DDR in NPC cells treated with CDDP and PARP inhibitor. Thus, MGMT is a promising therapeutic target for cancer treatments involving HR-associated DDR.

New Insights Into Oral Squamous Cell Carcinoma: From Clinical Aspects to Molecular Tumorigenesis.

Oral squamous cell carcinoma (SCC) is a prevalent malignant disease worldwide, especially so in Taiwan. Early- or even preclinical-stage detection is critical for reducing morbidity and mortality from oral SCC. Epidemiological and genome association studies are useful for identifying clinicopathological risk factors for preventive, diagnostic, and therapeutic approaches of oral SCC. For advanced oral SCC, effective treatments are critical to prolonging survival and enhancing quality of life. As oral SCC is characteristic of regional invasion with lymph node metastases, understanding the aggressive features of oral SCC, particularly in lymphangiogenesis, is essential for determining effective treatments. Emerging evidence has demonstrated that the tumor microenvironment (TME) plays a pivotal role in tumor growth, invasion, and metastases. Recent clinical successes in immune checkpoint inhibitors either alone or combined with chemotherapy have also supported the therapeutic value of immunotherapy in oral SCC. This review summarizes critical advances in basic knowledge of oral SCC from the perspective of clinicopathological risk factors, molecular tumorigenesis, and the TME. We also highlight our recent investigations on the microbiome, genome association studies, lymphangiogenesis, and immunomodulation in oral SCC. This review may provide new insights for oral SCC treatment by systematically interpreting emerging evidence from various preclinical and clinical studies.

SOD2 Enhancement by Long-Term Inhibition of the PI3K Pathway Confers Multi-Drug Resistance and Enhanced Tumor-Initiating Features in Head and Neck Cancer.

The phosphoinositide-3-kinase (PI3K) pathway has widely been considered as a potential therapeutic target for head and neck cancer (HNC); however, the application of PI3K inhibitors is often overshadowed by the induction of drug resistance with unknown mechanisms. In this study, PII3K inhibitor resistant cancer cells were developed by prolonged culturing of cell lines with BEZ235, a dual PI3K and mammalian target of rapamycin (mTOR) inhibitor. The drug resistant HNC cells showed higher IC50 of the proliferation to inhibitors specifically targeting PI3K and/or mTOR, as compared to their parental cells. These cells also showed profound resistance to drugs of other classes. Molecular analysis revealed persistent activation of phosphorylated AKT at threonine 308 in the drug resistant cells and increased expression of markers for tumor-initiating cells. Interestingly, increased intra-cellular ROS levels were observed in the drug resistant cells. Among anti-oxidant molecules, the expression of SOD2 was increased and was associated with the ALDH-positive tumor-initiating cell features. Co-incubation of SOD inhibitors and BEZ235 decreased the stemness feature of the cells in vitro, as shown by results of the spheroid formation assay. In conclusion, dysregulation of SOD2 might contribute to the profound resistance to PI3K inhibitors and the other drugs in HNC cells.

Treatment monitoring of colorectal cancer by integrated analysis of plasma concentration and sequencing of circulating tumor DNA.

Circulating cell-free DNA (cfDNA) analysis is an important tool for cancer monitoring. The patient-specific mutations identified in colorectal cancer (CRC) tissues are usually used to design the cfDNA analysis. Despite high specificity in predicting relapse, the sensitivity in most studies is around 40-50%. To improve this weakness, we designed a cfDNA panel according to the CRC genomic landscape and recurrent-specific mutations. The pathological variants in cfDNA samples from 60 CRC patients were studied by a next-generation sequencing (NGS) method incorporating the dual molecular barcode. Interestingly, patients in the disease positive group had a significantly higher cfDNA concentration than those in the disease negative group. Based on receiver operating characteristic analysis, the cfDNA concentration of 7 ng/mL was selected into the analytical workflow. The sensitivity in determining the disease status was 72.4%, which represented a considerable improvement on prior studies, and the specificity remained high at 80.6%. Compared to standard imaging and laboratory studies, earlier detection of residual disease and clinical benefits were shown on two cases by this cfDNA assay. We conclude this integrative framework of cfDNA analytical pipeline with a satisfactory sensitivity and specificity could be used in postoperative CRC surveillance.

Emergence of RAS mutations in patients with metastatic colorectal cancer receiving cetuximab-based treatment: a study protocol.

BACKGROUND: In the management of patients with RAS wild-type metastatic colorectal cancer (mCRC), anti-epidermal growth factor receptor (EGFR) therapies have demonstrated a clinical benefit, with longer survival. However, the correlation between the emergence of circulating RAS mutations and secondary resistance to anti-EGFR therapies requires further elucidation. In this study, we aim to examine evolutionary changes in RAS mutations through liquid biopsy in patients with mCRC during and after anti-EGFR therapy. METHODS: A total of 120 patients diagnosed with RAS wild-type mCRC will be enrolled in this study. Patients will receive a cetuximab-based infusional 5-fluorouracil regimen as first-line treatment. Cetuximab-based treatment is expected to continue until disease progression, intolerable toxic effects, or withdrawal of consent. Blood samples from enrolled patients will be collected before and then every 3 months during cetuximab-based treatment and also at disease progression. These blood samples will be evaluated for RAS resistance mutations by using the MassARRAY platform. The primary endpoint is the percentage of RAS mutations detected in circulating DNA from patients during cetuximab treatment. The correlation between the tumor response and survival outcomes of these patients and the emergence of circulating RAS mutations will be further analyzed. DISCUSSION: Liquid biopsy is a powerful technology that can represent tumor heterogeneity in a relatively noninvasive manner. Because RAS mutations play a major role in resistance to anti-EGFR therapy for mCRC, examining evolutionary changes in these mutations during such treatment through liquid biopsy would be useful. After comprehensively analyzing the emergence of circulating RAS mutations and its clinical relevance in this study, our results should provide practical guidance on anti-EGFR therapy for mCRC. TRIAL REGISTRATION: The date of trial registration ( NCT03401957 ) in this study was January 17, 2018.

Enrichment of superoxide dismutase 2 in glioblastoma confers to acquisition of temozolomide resistance that is associated with tumor-initiating cell subsets.

BACKGROUND: Intratumor subsets with tumor-initiating features in glioblastoma are likely to survive treatment. Our goal is to identify the key factor in the process by which cells develop temozolomide (TMZ) resistance. METHODS: Resistant cell lines derived from U87MG and A172 were established through long-term co-incubation of TMZ. Primary tumors obtained from patients were maintained as patient-derived xenograft for studies of tumor-initating cell (TIC) features. The cell manifestations were assessed in the gene modulated cells for relevance to drug resistance. RESULTS: Among the mitochondria-related genes in the gene expression databases, superoxide dismutase 2 (SOD2) was a significant factor in resistance and patient survival. SOD2 in the resistant cells functionally determined the cell fate by limiting TMZ-stimulated superoxide reaction and cleavage of caspase-3. Genetic inhibition of the protein led to retrieval of drug effect in mouse study. SOD2 was also associated with the TIC features, which enriched in the resistant cells. The CD133+ specific subsets in the resistant cells exhibited superior superoxide regulation and the SOD2-related caspase-3 reaction. Experiments applying SOD2 modulation showed a positive correlation between the TIC features and the protein expression. Finally, co-treatment with TMZ and the SOD inhibitor sodium diethyldithiocarbamate trihydrate in xenograft mouse models with the TMZ-resistant primary tumor resulted in lower tumor proliferation, longer survival, and less CD133, Bmi-1, and SOD2 expression. CONCLUSION: SOD2 plays crucial roles in the tumor-initiating features that are related to TMZ resistance. Inhibition of the protein is a potential therapeutic strategy that can be used to enhance the effects of chemotherapy.

New Insights into Mechanisms of Cisplatin Resistance: From Tumor Cell to Microenvironment.

Although cisplatin has been a pivotal chemotherapy drug in treating patients with various types of cancer for decades, drug resistance has been a major clinical impediment. In general, cisplatin exerts cytotoxic effects in tumor cells mainly through the generation of DNA-platinum adducts and subsequent DNA damage response. Accordingly, considerable effort has been devoted to clarify the resistance mechanisms inside tumor cells, such as decreased drug accumulation, enhanced detoxification activity, promotion of DNA repair capacity, and inactivated cell death signaling. However, recent advances in high-throughput techniques, cell culture platforms, animal models, and analytic methods have also demonstrated that the tumor microenvironment plays a key role in the development of cisplatin resistance. Recent clinical successes in combination treatments with cisplatin and novel agents targeting components in the tumor microenvironment, such as angiogenesis and immune cells, have also supported the therapeutic value of these components in cisplatin resistance. In this review, we summarize resistance mechanisms with respect to a single tumor cell and crucial components in the tumor microenvironment, particularly focusing on favorable results from clinical studies. By compiling emerging evidence from preclinical and clinical studies, this review may provide insights into the development of a novel approach to overcome cisplatin resistance.

High chloride channel accessory 1 expression predicts poor prognoses in patients with rectal cancer receiving chemoradiotherapy.

Background: Concurrent chemoradiotherapy (CCRT) has now become the standard of treatments for advanced rectal cancer before surgery. To search the biological molecules with prognostic and therapeutic potential of CCRT could be beneficial for these patients. Recently, aberrant expression of chloride channels has been linked to radio-resistance in glioblastoma; however, its clinical implication has not been well-studied in rectal cancers. Therefore, we examined the clinical significance of targetable drivers associated with chloride channel activity in patients with rectal cancer receiving CCRT. Methods: After datamining from a published transcriptome of rectal cancers, upregulation of CLCA1 gene was recognized to be significantly correlated with non-responders of CCRT. In validation cohort of rectal cancers, the expression levels of CLCA1 were accessed by using immunohistochemistry assays in 172 tumor specimens that were obtained before any treatment. Expression levels of CLCA1 were statistically analyzed with principal clinicopathological features and survival outcomes in this substantial cohort. Results: In validation cohort, high expression of CLCA1 was significantly associated with higher pre-treatment tumor nodal stages (P=0.032), vascular invasion (P=0.028), and inferior tumor regression grade (P=0.042). In survival evaluations, high expression of CLCA1 was significantly correlated with worse local recurrence-free survival (LRFS; P=0.0012), metastasis-free survival (MeFS; P =0.0114), and disease-specific survival (DSS; P=0.0041). Furthermore, high expression of CLCA1 remained an independent prognosticator of shorter LRFS (P=0.029, hazard ratio=2.555), MeFS (P=0.044, hazard ratio=2.125) and DSS (P=0.044, hazard ratio=2.172). Conclusions: High expression of CLCA1 is significantly associated with poor therapeutic response and survival outcomes in rectal cancer patients with CCRT treatment before surgery. With the development of specific inhibitors, our findings indicate not only prognostic but also therapeutic potential of CLCA1 in rectal cancers.

O(6) -methylguanine DNA methyltransferase repairs platinum-DNA adducts following cisplatin treatment and predicts prognoses of nasopharyngeal carcinoma.

Cisplatin (CDDP) is an important anti-cancer drug commonly used in various human cancers, including nasopharyngeal carcinoma (NPC). How to overcome the drug resistance of CDDP provides opportunities to improve clinical outcomes of NPC. O(6) -methylguanine-DNA methyltransferase (MGMT) has been well-characterized to be a therapeutic determinant of O(6) -alkylguanine alkylating drugs. However, the underlying mechanism and clinical relevance between MGMT and CDDP remain poorly defined in NPC. In this study, we showed that MGMT-proficient cells were highly resistant to the cytotoxic effects of CDDP as compared to MGMT-deficient cells. Further studies showed that the platinum level of DNA after CDDP exposure was significantly lower in MGMT-proficient cells than in MGMT-deficient cells. Host cell reactivation assay revealed that MGMT protected NPC cells from CDDP-induced DNA damage by enhancing DNA repair capacity. Importantly, we demonstrated for the first time that MGMT protein directly bound to CDDP-induced DNA damages. Subsequently, CDDP-bound MGMT protein became ubiquitinated and was degraded through ubiquitin-mediated proteasome system. We further analyzed the relationship between MGMT expression and clinical survivals in a cohort of 83 NPC patients. NPC patients who received CDDP-based concurrent chemoradiotherapy (CCRT), with high MGMT expression level, exhibited shorter progression-free survival (PFS; p = 0.022) and overall survival (OS; p = 0.015), than patients with low MGMT expression level. Furthermore, high MGMT expression level remained to be an independent prognostic factor for worse PFS (p = 0.01, hazard ratio 2.23) and OS (p = 0.018, hazard ratio 2.14). Our findings suggest that MGMT protein is important to determine the efficacy of CDDP in NPC.

Deficiency in asparagine synthetase expression in rectal cancers receiving concurrent chemoradiotherapy: negative prognostic impact and therapeutic relevance.

Locally advanced rectal cancers are currently treated with neoadjuvant concurrent chemoradiotherapy (CCRT) followed by surgery, but risk stratification and final outcomes remain suboptimal. In this study, we identify and validate targetable metabolic drivers relevant to the prognosis of patients with rectal cancer treated with CCRT. Using a published transcriptome of rectal cancers, we found that asparagine synthetase (ASNS) gene significantly predicted the response to CCRT. From 172 patients with rectal cancer, the expression levels of ASNS, using immunohistochemistry assays, were further evaluated in tumor specimens initially obtained by using colonoscopy. Expression levels of ASNS were further correlated with major clinicopathological features and clinical survivals in this valid cohort. ASNS deficiency was significantly related to advanced posttreatment tumor (T3, T4; P = .015) and nodal status (N1, N2; P = .004) and inferior tumor regression grade (P < .001). In survival analyses, ASNS deficiency was significantly associated with shorter local recurrence-free survival (LRFS; P = .0039), metastasis-free survival (MeFS; P = .0001), and disease-specific survival (DSS; P = .0006). Furthermore, ASNS deficiency was independently predictive of worse outcomes for MeFS (P = .012, hazard ratio = 3.691) and DSS (P = .022, hazard ratio = 2.845), using multivariate analysis. ASNS deficiency is correlated with poor therapeutic response and worse survivals in patients with rectal cancer receiving neoadjuvant CCRT. These findings indicate that ASNS is a prognostic factor with therapeutic potential for treating rectal cancer.

Comprehensive genomic profiling and therapeutic implications for Taiwanese patients with treatment-naïve breast cancer.

BACKGROUND: Breast cancer is a heterogeneous disease categorized based on molecular characteristics, including hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) expression levels. The emergence of profiling technology has revealed multiple driver genomic alterations within each breast cancer subtype, serving as biomarkers to predict treatment outcomes. This study aimed to explore the genomic landscape of breast cancer in the Taiwanese population through comprehensive genomic profiling (CGP) and identify diagnostic and predictive biomarkers. METHODS: Targeted next-generation sequencing-based CGP was performed on 116 archived Taiwanese breast cancer specimens, assessing genomic alterations (GAs), including single nucleotide variants, copy number variants, fusion genes, tumor mutation burden (TMB), and microsatellite instability (MSI) status. Predictive variants for FDA-approved therapies were evaluated within each subtype. RESULTS: In the cohort, frequent mutations included PIK3CA (39.7%), TP53 (36.2%), KMT2C (9.5%), GATA3 (8.6%), and SF3B1 (6.9%). All subtypes had low TMB, with no MSI-H tumors. Among HR + HER2- patients, 42% (27/65) harbored activating PIK3CA mutations, implying potential sensitivity to PI3K inhibitors and resistance to endocrine therapies. HR + HER2- patients exhibited intrinsic hormonal resistance via FGFR1 gene gain/amplification (15%), exclusive of PI3K/AKT pathway alterations. Aberrations in the PI3K/AKT/mTOR and FGFR pathways were implicated in chemoresistance, with a 52.9% involvement in triple-negative breast cancer. In HER2+ tumors, 50% harbored GAs potentially conferring resistance to anti-HER2 therapies, including PIK3CA mutations (32%), MAP3K1 (2.9%), NF1 (2.9%), and copy number gain/amplification of FGFR1 (18%), FGFR3 (2.9%), EGFR (2.9%), and AKT2 (2.9%). CONCLUSION: This study presents CGP findings for treatment-naïve Taiwanese breast cancer, emphasizing its value in routine breast cancer management, disease classification, and treatment selection.

Topical Antibiotic Prophylaxis for Preventing Surgical Site Infections of Clean Wounds: A Systematic Review and Meta-Analysis.

Background: Topical antibiotic agents are not generally indicated for preventing of surgical site infections (SSIs) in clean incisions, and the drug concentrations that should be delivered to local incision sites remain uncertain. The aim of this study was to critically assess the efficacy of topical antibiotic agents in comparison with non-antibiotic agents for preventing SSIs in clean incisions by performing a systematic review and meta-analysis. Methods: We conducted a search of literature in PubMed, Embase, and Cochrane Databases and included randomized controlled trials (RCTs) on topical antibiotic use for patients with clean post-surgical incisions. The primary outcome was the incidence of SSI, presented as the event rate. Eleven RCTs were included. Results: Using random-effects modeling, the pooled risk ratio (RR) of developing a post-surgical incisions infection was 0.83 (95% confidence interval [CI], 0.61-1.16; I2, 0%). In subgroup analyses, no reductions in SSI were observed when topical antibiotic agents were used to treat incisions due to spinal (RR, 0.75; 95% CI, 0.40-1.38; I2, 0%), orthopedic (RR, 0.69; 95% CI, 0.37-1.29; I2, 0%), dermatologic (RR, 0.77; 95% CI, 0.39-1.55; I2, 65%), or cardiothoracic surgeries (RR, 1.31; 95% CI, 0.83-2.06; I2: 0%). The incidence of SSI across different operative phases did not differ for the application of topical antibiotic agents compared with non-antibiotic agents (RR, 0.80; 95% CI, 0.56-1.14; I2, 0%). Conclusions: The results of this meta-analysis show that topical antibiotic agents provide no clinical benefit for preventing SSI in clean incisions.

Predictive value of FCGBP expression for treatment response and survival in rectal cancer patients undergoing chemoradiotherapy.

Despite neoadjuvant chemoradiotherapy (CRT) being the established standard for treating advanced rectal cancer, clinical outcomes remain suboptimal, necessitating the identification of predictive biomarkers for improved treatment decisions. Previous studies have hinted at the oncogenic properties of the Fc fragment of IgG binding protein (FCGBP) in various cancers; however, its clinical significance in rectal cancer remains unclear. In this study, we first conducted an analysis of a public transcriptome comprising 46 rectal cancer patients. Focusing on cell adhesion during data mining, we identified FCGBP as the most upregulated gene associated with CRT resistance. Subsequently, we assessed FCGBP immunointensity using immunohistochemical staining on 343 rectal cancer tissue blocks. Elevated FCGBP immunointensity correlated with lymph node involvement before treatment (p = 0.001), tumor invasion, and lymph node involvement after treatment (both p < 0.001), vascular invasion (p = 0.001), perineural invasion (p = 0.041), and reduced tumor regression (p < 0.001). Univariate analysis revealed a significant association between high FCGBP immunoexpression and inferior disease-specific survival, local recurrence-free survival, and metastasis-free survival (all p ≤ 0.0002). Furthermore, high FCGBP immunoexpression independently emerged as an unfavorable prognostic factor for all three survival outcomes in the multivariate analysis (all p ≤ 0.025). Enriched pathway analysis substantiated the role of FCGBP in conferring resistance to radiation. In summary, our findings suggest that elevated FCGBP immunoexpression in rectal cancer significantly correlates with a poor response to CRT and diminished patient survival. FCGBP holds promise as a valuable prognostic biomarker for rectal cancer patients undergoing CRT.

SKP2 overexpression is associated with a poor prognosis of rectal cancer treated with chemoradiotherapy and represents a therapeutic target with high potential.

The S-phase kinase-associated protein 2 (SKP2) oncoprotein is an E3 ubiquitin ligase. Overexpression of SKP2 was found in various human cancers, including colorectal cancers, but its potential role as a prognostic marker after neoadjuvant chemoradiotherapy (CRT) and for therapeutic intervention in rectal cancers is unknown. This study examined the correlation of SKP2 expression in the prognosis of rectal cancer patients and the viability of colorectal cancer cells treated with CRT. SKP2 immunoexpression was retrospectively assessed in pretreatment biopsies of 172 rectal cancer patients treated with neoadjuvant CRT followed by surgery. Results were correlated with clinicopathological features, therapeutic responses, and patient survival. Pharmacologic assays were used to evaluate the therapeutic relevance of Bortezomib in two colorectal cancer cell lines (HT-29 and SW480). High expression of SKP2 was correlated with the advanced Post-Tx nodal status (p = 0.002), Post-Tx International Union for Cancer Control stage (p = 0.002), and a lower-degree tumor regression grade (p < 0.001). Moreover, high expression of SKP2 (p = 0.027, hazard ratio 3.21) was an independent prognostic factor for local recurrence-free survival. In vitro, Bortezomib downregulated SKP2 expression, induced caspase activation, and decreased the viability of colorectal cancer cells with or without a combination with fluorouracil. Bortezomib also promoted caspase activation and gamma-H2AX formation in colorectal cancer cells concurrently treated with CRT. High expression of SKP2 was associated with a poor therapeutic response and adverse outcomes in rectal cancer patients treated with neoadjuvant CRT. In the presence of chemotherapy with or without radiotherapy, the promoted sensitivity of colorectal cancer cells to Bortezomib with an SKP2-repressing effect indicated that it is a potential therapeutic target.

Dissecting the EGFR-PI3K-AKT pathway in oral cancer highlights the role of the EGFR variant III and its clinical relevance.

BACKGROUND: Dysregulated epidermal growth factor receptor (EGFR)-phosphoinositide-3-kinase (PI3K)-AKT signaling is considered pivotal for oral cancer, and the pathway is a potential candidate for therapeutic targeting. RESULTS: A total of 108 archival samples which were from surgically resected oral cancer were examined. Immunohistochemical staining showed the protein expression of membranous wild-type EGFR and cytoplasmic phosphorylated AKT was detected in 63.9% and 86.9% of the specimens, respectively. In 49.1% of the samples, no phosphatase and tensin homolog (PTEN) expression was detected. With regard to the EGFR variant III (EGFRvIII), 75.0% of the samples showed positive expression for moderate to severe staining, 31.5% of which had high expression levels. Real-time polymerase chain reaction assays for gene copy number assessment of PIK3CA revealed that 24.8% of the samples had alterations, and of EGFR showed that 49.0% had amplification. Direct sequencing of PIK3CA gene showed 2.3% of the samples had a hotspot point mutation. Statistical assessment showed the expression of the EGFRvIII correlated with the T classification and TNM stage. The Kaplan-Meier analyses for patient survival showed that the individual status of phosphorylated AKT and EGFRvIII led to significant differences in survival outcome. The multivariate analysis indicated that phosphorylated AKT, EGFRvIII expression and disease stage were patient survival determinants. CONCLUSIONS: Aberrations in the EGFR-PI3K-AKT pathway were frequently found in oral cancers. EGFRvIII and phosphorylated AKT were predictors for the patient survival and clinical outcome.