Related Experiment Video
Updated: Jan 20, 2026
Culture of Bladder Cancer Organoids as Precision Medicine Tools
Published on: December 28, 2021
Let-7 as biomarker, prognostic indicator, and therapy for precision medicine in cancer
Evgeny Chirshev1, Kerby C Oberg2, Yevgeniya J Ioffe3
1Division of Anatomy, Department of Basic Sciences, Loma Linda University, Loma Linda, CA, USA.
Abstract:
Abnormal regulation and expression of microRNAs (miRNAs) has been documented in various diseases including cancer. The miRNA let-7 (MIRLET7) family controls developmental timing and differentiation. Let-7 loss contributes to carcinogenesis via an increase in its target oncogenes and stemness factors. Let-7 targets include genes regulating the cell cycle, cell signaling, and maintenance of differentiation. It is categorized as a tumor suppressor because it reduces cancer aggressiveness, chemoresistance, and radioresistance. However, in rare situations let-7 acts as an oncogene, increasing cancer migration, invasion, chemoresistance, and expression of genes associated with progression and metastasis. Here, we review let-7 function as tumor suppressor and oncogene, considering let-7 as a potential diagnostic and prognostic marker, and a therapeutic target for cancer treatment. We explain the complex regulation and function of different let-7 family members, pointing to abnormal processes involved in carcinogenesis. Let-7 is a promising option to complement conventional cancer therapy, but requires a tumor specific delivery method to avoid toxicity. While let-7 therapy is not yet established, we make the case that assessing its tumor presence is crucial when choosing therapy. Clinical data demonstrate that let-7 can be used as a biomarker for rational precision medicine decisions, resulting in improved patient survival.
Insights
The microRNA let-7 (MIRLET7) family acts as both a tumor suppressor and oncogene in cancer. Assessing let-7 levels is crucial for personalized cancer therapy and improving patient survival.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- MicroRNAs (miRNAs), including the let-7 (MIRLET7) family, are crucial regulators of gene expression implicated in various diseases, notably cancer.
- Aberrant let-7 expression contributes to carcinogenesis by affecting oncogenes, stemness factors, cell cycle, signaling, and differentiation maintenance.
- The dual role of let-7 as a tumor suppressor (reducing aggressiveness, chemoresistance, radioresistance) and oncogene (promoting migration, invasion, metastasis) highlights its complex involvement in cancer.
Purpose of the Study:
- To review the multifaceted functions of let-7 family members in cancer, encompassing both tumor suppressive and oncogenic roles.
- To explore the potential of let-7 as a diagnostic and prognostic biomarker for cancer.
- To discuss let-7 as a therapeutic target for cancer treatment, considering its complex regulation and delivery challenges.
Main Methods:
- Comprehensive literature review of studies investigating let-7 family members in various cancers.
- Analysis of let-7's regulatory mechanisms and functional consequences on cellular processes relevant to carcinogenesis.
- Evaluation of clinical data supporting let-7's utility as a biomarker and therapeutic agent.
Main Results:
- Let-7 family members exhibit context-dependent roles, acting as tumor suppressors by inhibiting cancer progression and as oncogenes by promoting metastasis.
- Dysregulation of let-7 is frequently observed in carcinogenesis, impacting key cellular pathways.
- Clinical data indicate let-7's potential as a biomarker for precision medicine, guiding therapeutic decisions and improving patient outcomes.
Conclusions:
- Let-7 plays a critical, albeit complex, role in cancer development and progression, functioning as both a tumor suppressor and an oncogene.
- let-7 represents a promising biomarker for personalized cancer therapy and a potential therapeutic target.
- Further research into tumor-specific delivery methods is essential for realizing the full therapeutic potential of let-7 in cancer treatment.
Related Concept Videos
08:39Culture of Bladder Cancer Organoids as Precision Medicine Tools
06:24Establishment of Coloproctitis Cancer Model in Mice and Evaluation of Therapeutic Effect of Chinese Medicine
06:37Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke
02:39Indicators
02:50Combination Therapies and Personalized Medicine
The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and...
07:41Performing Data Mining And Integrative Analysis Of Biomarker in Breast Cancer Using Multiple Publicly Accessible Databases