Clinical study of colorectal cancer operation: Survival analysis

Expression Pattern of PDE4B, PDE4D, and SFRP5 Markers in Colorectal Cancer

Background and Objectives: Colorectal cancer (CRC) is the most frequently diagnosed malignant disease of the gastrointestinal system, and new diagnostic and prognostic markers are needed to elucidate the complete tumor profile. Materials and Methods: We used CRC tumor tissues (Dukes' A-D) and adjacent noncancerous tissues of 43 patients. Immunohistochemistry was used to examine the expression of phosphodiesterase 4B (PDE4B), phosphodiesterase 4D (PDE4D), and secreted frizzled related protein 5 (SFRP5) markers. We also analyzed the expression levels of PDE4B, PDE4D, and SFRP5 in CRC tissues compared to control tissues using RNA-sequencing data from the UCSC Xena browser. Results: In CRC stages, the distribution of PDE4B-positive cells varied, with differing percentages between epithelium and lamina propria. Statistically significant differences were found in the number of PDE4B-positive epithelial cells between healthy controls and all CRC stages, as well as between different CRC stages. Similarly, significant differences were observed in the number of PDE4B-positive cells in the lamina propria between healthy controls and all CRC stages, as well as between different CRC stages. CRC stage Dukes' C exhibited a significantly higher number of PDE4B-positive cells in the lamina propria compared to CRC stage Dukes' B. Significant differences were noted in the number of PDE4D-positive epithelial cells between healthy controls and CRC stages Dukes' A, B, and D, as well as between CRC stage Dukes' C and stages A, B, and D. CRC stage Dukes' A had significantly more PDE4D-positive cells in the lamina propria compared to stage D. Significant differences were also observed in the number of SFRP5-positive cells in the lamina propria between healthy controls and all CRC stages, as well as between CRC stages Dukes' A and D. While the expression of PDE4D varied across CRC stages, the expression of SFRP5 remained consistently strong in both epithelium and lamina propria, with significant differences noted mainly in the lamina propria. The expression levels of PDE4B, PDE4D, and SFRP5 reveal significant differences in the expression of these genes between CRC patients and healthy controls, with notable implications for patient prognosis. Namely, our results demonstrate that PDE4B, PDE4D, and SFRP5 are significantly under-expressed in CRC tissues compared to control tissues. The Kaplan-Meier survival analysis and the log-rank (Mantel-Cox) test revealed distinct prognostic implications where patients with lower expression levels of SFRP5 exhibited significantly longer overall survival. The data align with our immunohistochemical results and might suggest a potential tumor-suppressive role for these genes in CRC. Conclusions: Considering significantly lower gene expression, aligned with our immunohistochemical data in tumor tissue in comparison to the control tissue, as well as the significantly poorer survival rate in the case of its higher expression, we can hypothesize that SFRP5 is the most promising biomarker for CRC out of the observed proteins. These findings suggest alterations in PDE4B, PDE4D, and SFRP5 expression during CRC progression, as well as between different stages of CRC, with potential implications for understanding the molecular mechanisms involved in CRC development and progression.

Exploring the Key Signaling Pathways and ncRNAs in Colorectal Cancer

Colorectal cancer (CRC) is the third most prevalent cancer to be diagnosed, and it has a substantial mortality rate. Despite numerous studies being conducted on CRC, it remains a significant health concern. The disease-free survival rates notably decrease as CRC progresses, emphasizing the urgency for effective diagnostic and therapeutic approaches. CRC development is caused by environmental factors, which mostly lead to the disruption of signaling pathways. Among these pathways, the Wingless/Integrated (Wnt) signaling pathway, Phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway, Mitogen-Activated Protein Kinase (MAPK) signaling pathway, Transforming Growth Factor-β (TGF-β) signaling pathway, and p53 signaling pathway are considered to be important. These signaling pathways are also regulated by non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). They have emerged as crucial regulators of gene expression in CRC by changing their expression levels. The altered expression patterns of these ncRNAs have been implicated in CRC progression and development, suggesting their potential as diagnostic and therapeutic targets. This review provides an overview of the five key signaling pathways and regulation of ncRNAs involved in CRC pathogenesis that are studied to identify promising avenues for diagnosis and treatment strategies.

Targeting the "tumor microenvironment": RNA-binding proteins in the spotlight in colorectal cancer therapy

Colorectal cancer (CRC) is the third most common cancer and has the second highest mortality rate among cancers. The development of CRC involves both genetic and epigenetic abnormalities, and recent research has focused on exploring the ex-transcriptome, particularly post-transcriptional modifications. RNA-binding proteins (RBPs) are emerging epigenetic regulators that play crucial roles in post-transcriptional events. Dysregulation of RBPs can result in aberrant expression of downstream target genes, thereby affecting the progression of colorectal tumors and the prognosis of patients. Recent studies have shown that RBPs can influence CRC pathogenesis and progression by regulating various components of the tumor microenvironment (TME). Although previous research on RBPs has primarily focused on their direct regulation of colorectal tumor development, their involvement in the remodeling of the TME has not been systematically reported. This review aims to highlight the significant role of RBPs in the intricate interactions within the CRC tumor microenvironment, including tumor immune microenvironment, inflammatory microenvironment, extracellular matrix, tumor vasculature, and CRC cancer stem cells. We also highlight several compounds under investigation for RBP-TME-based treatment of CRC, including small molecule inhibitors such as antisense oligonucleotides (ASOs), siRNAs, agonists, gene manipulation, and tumor vaccines. The insights gained from this review may lead to the development of RBP-based targeted novel therapeutic strategies aimed at modulating the TME, potentially inhibiting the progression and metastasis of CRC.

Evaluation of Stages, Treatment Protocols, and Outcomes of Colorectal Cancer among West Bank Patients

Background: Colorectal cancer (CRC) is the second most widespread cancer among Palestinian patients. As cancer care improves in hospitals across the West Bank, services like palliative care, targeted therapy, bone marrow transplantation, and individualized therapy are still limited. This study aimed to assess the CRC stages, treatment protocols, and survival rates of patients in the West Bank. Methodology: This retrospective study collected data from the medical records of Al-Najah University Hospital (NUH), which specializes in the care of cancer patients. Patients with confirmed CRC (stages I-IV) undergoing surgical or medical treatment were included in the study. Data collection was standardized by using a data collection form to gather information from the medical records included in the study. All statistical analyses were performed using SPSS (version v27), and survival was assessed using a regression analysis of the number of days from the time of diagnosis to the most recent visit against the type of treatment (e.g., surgery, chemotherapy, radiotherapy). Results: A sample of 252 patients with CRC from NUH was collected, including 143 males and 109 females aged between 27 and 86 years, with the average age being 60.6 ± 11.4 years. The sample included 183 patients (72.6%) diagnosed with colon cancer only, 29 patients (11.5%) diagnosed with rectal cancer only, and 40 patients (15.9%) diagnosed with both. Diagnosis took place at CRC stage I for 3 patients (1.2%), stage II for 33 patients (13.1%), stage III for 57 patients (22.6%), and stage IV for 159 patients (63.1%). Surgery was the most prevailing mode of treatment for 230 patients (91.3%), while 227 patients (90.1%) received chemotherapy treatment, and 38 patients (15.1%) received radiotherapy. Of the 252 patients, 40 patients (15.8%) received FOLFOX (i.e., folinic acid, fluorouracil, oxaliplatin), and 25 patients (9.9%) received FOLFIRI (i.e., folinic acid, fluorouracil, irinotecan), while the 187 remaining patients (74.2%) were treated with capecitabine, oxaliplatin, bevacizumab, cetuximab, regorafenib, cisplatin, etoposide, gemcitabine, or a combination thereof. The sample was categorized into six outcomes: (1) death, (2) cure, (3) disease progression, (4) disease recurrence, (5) under-treatment, and (6) unknown. Mortality was high, with 104 patients (41.3%) dying within a short time after diagnosis, and may have been attributable to delayed diagnosis. Surgical treatment had a positive impact on increasing the survival years, and it was significant (p = 0.033). Conclusions: A high percentage of patients were diagnosed in advanced CRC stages. The treatment modes were adopted from general international guidelines; however, the cure rates were low, and mortality was high. More studies need to be undertaken to investigate the actual application of chemotherapy protocols, and survival would benefit from the involvement of clinical pharmacists in the chemotherapy protocol selection, dosing, frequency, and follow-up. The present study advocates for greater public awareness of CRC and attests to the merits of screening by primary care professionals, which can help to avoid this serious illness and to promote a better prognosis.

AutoPepVax, a Novel Machine-Learning-Based Program for Vaccine Design: Application to a Pan-Cancer Vaccine Targeting EGFR Missense Mutations

The current epitope selection methods for peptide vaccines often rely on epitope binding affinity predictions, prompting the need for the development of more sophisticated in silico methods to determine immunologically relevant epitopes. Here, we developed AutoPepVax to expedite and improve the in silico epitope selection for peptide vaccine design. AutoPepVax is a novel program that automatically identifies non-toxic and non-allergenic epitopes capable of inducing tumor-infiltrating lymphocytes by considering various epitope characteristics. AutoPepVax employs random forest classification and linear regression machine-learning-based models, which are trained with datasets derived from tumor samples. AutoPepVax, along with documentation on how to run the program, is freely available on GitHub. We used AutoPepVax to design a pan-cancer peptide vaccine targeting epidermal growth factor receptor (EGFR) missense mutations commonly found in lung adenocarcinoma (LUAD), colorectal adenocarcinoma (CRAD), glioblastoma multiforme (GBM), and head and neck squamous cell carcinoma (HNSCC). These mutations have been previously targeted in clinical trials for EGFR-specific peptide vaccines in GBM and LUAD, and they show promise but lack demonstrated clinical efficacy. Using AutoPepVax, our analysis of 96 EGFR mutations identified 368 potential MHC-I-restricted epitope-HLA pairs from 49,113 candidates and 430 potential MHC-II-restricted pairs from 168,669 candidates. Notably, 19 mutations presented viable epitopes for MHC I and II restrictions. To evaluate the potential impact of a pan-cancer vaccine composed of these epitopes, we used our program, PCOptim, to curate a minimal list of epitopes with optimal population coverage. The world population coverage of our list ranged from 81.8% to 98.5% for MHC Class II and Class I epitopes, respectively. From our list of epitopes, we constructed 3D epitope-MHC models for six MHC-I-restricted and four MHC-II-restricted epitopes, demonstrating their epitope binding potential and interaction with T-cell receptors. AutoPepVax's comprehensive approach to in silico epitope selection addresses vaccine safety, efficacy, and broad applicability. Future studies aim to validate the AutoPepVax-designed vaccines with murine tumor models that harbor the studied mutations.

Performance and Dimensionality of Pretreatment MRI Radiomics in Rectal Carcinoma Chemoradiotherapy Prediction

(1) Background: This study aimed to develop a machine learning model based on radiomics of pretreatment magnetic resonance imaging (MRI) 3D T2W contrast sequence scans combined with clinical parameters (CP) to predict neoadjuvant chemoradiotherapy (nCRT) response in patients with locally advanced rectal carcinoma (LARC). The study also assessed the impact of radiomics dimensionality on predictive performance. (2) Methods: Seventy-five patients were prospectively enrolled with clinicopathologically confirmed LARC and nCRT before surgery. Tumor properties were assessed by calculating 2141 radiomics features. Least absolute shrinkage selection operator (LASSO) and multivariate regression were used for feature selection. (3) Results: Two predictive models were constructed, one starting from 72 CP and 107 radiomics features, and the other from 72 CP and 1862 radiomics features. The models revealed moderately advantageous impact of increased dimensionality, with their predictive respective AUCs of 0.86 and 0.90 in the entire cohort and 0.84 within validation folds. Both models outperformed the CP-only model (AUC = 0.80) which served as the benchmark for predictive performance without radiomics. (4) Conclusions: Predictive models developed in this study combining pretreatment MRI radiomics and clinicopathological features may potentially provide a routine clinical predictor of chemoradiotherapy responders, enabling clinicians to personalize treatment strategies for rectal carcinoma.

Three-dimensional laparoscopic surgery for colorectal cancer: A 2-year follow-up study at Hue Central Hospital

Background

Laparoscopic surgery has brought about a revolution in clinical practice since its inception. Using a new generation three-dimensional (3D) HD laparoscopic system can be seen as a beneficial "hybrid" created by fusing two different elements: increased vision quality and the viability and diffusion of laparoscopy. This study aims to determine the surgical outcomes and two-year survival of colorectal cancer patients after 3D laparoscopic surgery.

Methods

A prospective study was conducted on 60 patients with a definitive diagnosis of primary colorectal cancer. All patients underwent 3D laparoscopic colorectal resection from January 2020 to December 2021 by a single surgical team. Data were prospectively collected from Hue Central Hospital, including operative parameters and survival time.

Results

The mean age was 62.0 ± 10.6 years old. D3 lymphadenectomy accounted for most cases (96.7 %). There were no intraoperative complications or conversion to open surgery. The mean operation time was 162.3 ± 25.8 min. Postoperative complications included incisional fluid collection (5 %), wound infection (3.3 %), and drainage site bleeding (1.7 %). The average length of hospital stay was 10.4 ± 4.6 days. Overall survival rate after two years was 93 %.

Conclusions

3D laparoscopic surgery for radical treatment of colorectal cancer is feasible, effective, and safe. This surgical technique offers a positive prognosis for patients.

Chemotherapy reduces long-term quality of life in recurrence-free colon cancer survivors (LaTE study)-a nationwide inverse probability of treatment-weighted registry-based cohort study and survey

AIM

Stage III colon cancer is routinely treated with adjuvant chemotherapy, which causes significant short-term morbidity. Its effect on long-term quality of life (QoL) is poorly investigated. The aim of this study was to investigate long-term QoL after curative treatment for colon cancer and explore the impact of chemotherapy on general and disease-specific QoL.

METHOD

All patients aged under 75 years operated on for colon cancer between 30 September 2007 and 1 October 2019 were identified by the Cancer Registry of Norway. Exclusion criteria were distant metastasis, recurrence, dementia and rectal/rectosigmoid cancer operation. The primary outcome measure was Gastrointestinal Quality of Life Index (GIQLI). Secondary outcome measures included the Short Form Health Survey (SF-36). To achieve balanced groups when assessing differences in outcome measures the analyses were weighted by inverse probability weights based on a multiple logistic regression model with prechosen confounders.

RESULTS

A total of 8627 patients were invited and 3109 responded (36% response rate). After exclusions 3025 patients were included, of whom 1148 (38%) had received adjuvant chemotherapy and 1877 (62%) had surgery alone, with mean follow-up of 75.5 versus 74.5 months, respectively. The GIQLI differed significantly between the groups [mean 111.0 (SD 18.4) vs. 115.6 (SD 17.8), respectively; mean difference: -4.6 (95% CI -5.9; -3.2); p < 0.001]. Those with the highest neurotoxicity exhibited the lowest GIQLI. The adjuvant chemotherapy group scored significantly lower in six of eight SF-36 domains compared with the surgery alone group. The main differences were found in social, physical and emotional function.

CONCLUSION

Long-term QoL was significantly lower in patients who received adjuvant chemotherapy than in patients who did not. Neurotoxicity was closely related to reduced QoL in these patients. The low response rate limits the generalizability of the results.

Diabetic severity and oncological outcomes of colorectal cancer following curative resection: A population-based cohort study in Taiwan

BACKGROUND

Although diabetes is a poor prognostic factor for colorectal cancer (CRC), whether diabetes severity provides an additional predictive value for CRC prognosis remains unclear. The study aimed to investigate the prognostic differences after curative CRC resection among patients with different diabetic severities.

METHODS

This population-based retrospective cohort study analyzed data registered between 2007 and 2015 in the Cancer Registry Database, which is linked to the National Health Insurance Research Database and National Death Registry. Patients with CRC who underwent curative radical resection for stage I-III disease were evaluated, with their diabetic status subdivided into no diabetes, diabetes without complication, and diabetes with complications. Cox regressions were applied to determine the association between diabetes severity and CRC survival, including overall survival (OS), disease-free survival (DFS), time to recurrence, and cancer-specific survival (CSS).

RESULTS

A total of 59,202 patients with CRC were included. Compared with the no diabetes group, the diabetes without complication group has insignificantly worse OS (hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.01-1.09), DFS (HR, 1.08; 95% CI, 1.04-1.12), and CSS (HR, 0.98; 95% CI, 0.93-1.03), whereas those with complicated diabetes had a significantly higher risk of poor survival (OS: HR, 1.85; 95% CI, 1.78-1.92; DFS: HR, 1.75; 95% CI, 1.69-1.82; CSS: HR, 1.41; 95% CI, 1.33-1.49). Patients with CRC and diabetes also had a higher risk of recurrence than did those without diabetes. Sex and TNM staging were important effect modifiers.

CONCLUSIONS

Among patients with CRC who undergo curative resection, the severity of the diabetes is inversely correlated with long-term outcomes, especially in women and patients in the earlier stages of CRC.

PLAIN LANGUAGE SUMMARY

The prognostic impact of diabetes severity in colorectal cancer (CRC) is yet to be clarified. In this cohort study of 59,202 patients with CRC, compared with patients with CRC and without diabetes, those with uncomplicated diabetes had an insignificantly worse CRC survival, whereas those with complicated diabetes had a significantly higher risk of poor survival. Multidisciplinary medical care to prevent progression into diabetes with complications is needed to improve survival among patients with CRC and diabetes.

Local interventions for colorectal cancer metastases to liver and lung

BACKGROUND

Colorectal cancer is a common cause of cancer-related deaths. About 1/3 of all cases present with distant metastasis, with the liver as the leading site and the lung as the most common extra-abdominal site.

AIMS

It was aimed to evaluate the clinical characteristics and the outcomes of colorectal cancer patients with liver or lung metastasis who had received local treatments.

METHODS

This is a retrospective, cross-sectional, and descriptive study. The study was performed with colorectal cancer patients that referred to the medical oncology clinic of a university hospital between December 2013 and August 2021.

RESULTS

A total number of 122 patients who have received local treatments were included. Radiofrequency ablation was applied in 32 patients (26.2%), metastasis was surgically resected in 84 patients (68.9%), and stereotactic body radiotherapy was preferred in six patients (4.9%). At the first follow-up control after completion of local or multimodal treatment, no residual tumor was determined with radiological assessment in 88 patients (72.1%). The median progression-free survival (16.7 months vs 9.7 months) (p = .000) and the median overall survival (37.3 months vs 25.5 months) (p = .004) of these patients were significantly better than the patients with residual disease.

CONCLUSIONS

Local interventions that are applied to highly selected patients may improve the survival of metastatic colorectal cancer patients. A close follow-up after local therapies is important to diagnose recurrent disease because repeated local interventions may be possible to achieve better outcomes.

Clinicopathologic Significance of Heat Shock Protein 60 as a Survival Predictor in Colorectal Cancer

The role of heat shock protein 60 (HSP60), a mitochondrial chaperone, in tumor progression or its anti-tumor effects remains controversial. This study aimed to confirm the possibility of using HSP60 as a prognostic marker in patients with colorectal cancer (CRC), considering TNM classification for precise prediction. HSP60 expression increased with differentiation and p53 mutations in patients. However, compared to patients with high HSP60 expression, patients with low HSP60 expression had event-free survival and disease-specific survival hazard ratios (HRs) of 1.42 and 1.69, respectively. Moreover, when the survival rate was analyzed by combining TNM classification and HSP60 expression, the prognosis was poor, particularly when HSP60 expression was low in the late/advanced stage. This pattern was also observed with HSP family D member 1, HSPD1, the gene that encodes HSP60. Low HSPD1 expression was linked to lower overall survival and relapse-free survival rates, with HRs of 1.80 and 1.87, respectively. When TNM classification and HSPD1 expression were considered, CRC patients with low HSPD1 expression and advanced malignancy had a poorer prognosis than those with high HSPD1 expression. Thus, HSPD1/HSP60 can be a useful biomarker for a sophisticated survival prediction in late- and advanced-stage CRC, allowing the design of individualized treatment strategies.

Exosomal lncRNAs in gastrointestinal cancer

Gastrointestinal cancer (GIC) remains a leading cause of morbidity and mortality worldwide. Unfortunately, these cancers are diagnosed in advanced metastatic stages due to lack of reliable biomarkers that are sufficiently specific and sensitive in early disease. There has been growing evidence that circulating exosomes can be used to diagnose cancer non-invasively with limited risks and side effects. Furthermore, exosomal long non-coding RNAs (lncRNAs) are emerging as a new class of promising biomarkers in cancer. This review provides an overview of the extraction and detection of exosomal lncRNAs with a focus on their potential role in GIC.

Ethyl Protocatechuate Encapsulation in Solid Lipid Nanoparticles: Assessment of Pharmacotechnical Parameters and Preliminary In Vitro Evaluation for Colorectal Cancer Treatment

Colorectal cancer is one of the most diffused tumoral diseases. Since most medicaments employed for its treatment are debilitating, the use of naturally derived products, which can be effective against the mutated cells and, in addition, can reduce most inflammatory-related effects, could be extremely beneficial for the continued treatment of this disease. In this research, ethyl protocatechuate (PCAEE), a protocatechuic acid prodrug, was encapsulated in solid lipid nanoparticles (SLN) (prepared without and with Tween 80), which were characterized in terms of size, polydispersity index (PDI), zeta potential and thermotropic behavior. Encapsulation efficiency, release profile and interaction with a model of biomembrane were also assessed. The nanoparticles were tested in vitro on both healthy cells and on a model of tumoral cells. SLN prepared with Tween 80 was promising in terms of physicochemical properties (z-average of 190 nm, PDI 0.150 and zeta potential around -20 mV) and encapsulation efficiency (56%); they showed a desirable release profile, demonstrated an ability to penetrate and release the encapsulated PCAEE into a biomembrane model and were nontoxic on healthy cells. In addition, they caused a greater dose-dependent decrease in the viability of CaCo-2 cells than PCAEE alone. In conclusion, the formulation could be proposed for further studies to assess its suitability for the treatment of colorectal cancer.

Anti-metastatic effects of 1,2,3,4,6-Penta-O-galloyl-β-D-glucose in colorectal cancer: Regulation of cathepsin B-mediated extracellular matrix dynamics and epithelial-to-mesenchymal transition

Despite significant advances in the diagnosis and treatment of colorectal cancer (CRC), metastatic colorectal cancer still poses serious threat to CRC patients. The natural gallotannin 1,2,3,4,6-penta-O-galloyl-β-D-glucose (PGG) has been shown to possess anti-tumor effects on colon cancer cells, but its anti-metastatic effect is yet to be investigated. In this study, the effects of PGG on cell proliferation, colony formation ability, motility, migration were investigated in colon cancer cells using BrdU, colony formation, scratch, and transwell assays, respectively. Western blot assay was used for assessing protein expression. The orthotopic colon tumor-bearing mouse model and human colon cancer metastatic mouse model were employed to evaluate the anti-metastatic effects of PGG. Results showed that PGG exhibited not only anti-proliferative and colony formation inhibitory effects, but also inhibition on cell adhesion, motility, and migration in both HCT116 and colon 26-M01 cells via modulating protein expression of cathepsin B, FAK, cofilin, and epithelial-to-mesenchymal transition related proteins. In addition, PGG (10 or 15 mg/kg, i.p.) could significantly inhibit liver and lung metastasis in colon cancer metastatic mice models. Furthermore, PGG could regulate the populations of T cells, macrophages, and MDSCs, while the levels of IL-2, IL-6, IL-10, IFN-γ, and TNF-α were altered after PGG treatment in metastatic CRC mice. This is the first report of the anti-metastatic effects of PGG by regulating cathepsin B-mediated extracellular matrix dynamics and epithelial-to-mesenchymal transition process in CRC. Our findings suggested that PGG has great potential to be developed as an anti-metastatic agent for metastatic CRC.

Nanomaterial-Based Fluorescence Resonance Energy Transfer (FRET) and Metal-Enhanced Fluorescence (MEF) to Detect Nucleic Acid in Cancer Diagnosis

Nucleic acids, including DNA and RNA, have received prodigious attention as potential biomarkers for precise and early diagnosis of cancers. However, due to their small quantity and instability in body fluids, precise and sensitive detection is highly important. Taking advantage of the ease-to-functionality and plasmonic effect of nanomaterials, fluorescence resonance energy transfer (FRET) and metal-enhanced fluorescence (MEF)-based biosensors have been developed for accurate and sensitive quantitation of cancer-related nucleic acids. This review summarizes the recent strategies and advances in recently developed nanomaterial-based FRET and MEF for biosensors for the detection of nucleic acids in cancer diagnosis. Challenges and opportunities in this field are also discussed. We anticipate that the FRET and MEF-based biosensors discussed in this review will provide valuable information for the sensitive detection of nucleic acids and early diagnosis of cancers.